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Sample records for nonlocal envelope equations

  1. Nonlocal Equations with Measure Data

    NASA Astrophysics Data System (ADS)

    Kuusi, Tuomo; Mingione, Giuseppe; Sire, Yannick

    2015-08-01

    We develop an existence, regularity and potential theory for nonlinear integrodifferential equations involving measure data. The nonlocal elliptic operators considered are possibly degenerate and cover the case of the fractional p-Laplacean operator with measurable coefficients. We introduce a natural function class where we solve the Dirichlet problem, and prove basic and optimal nonlinear Wolff potential estimates for solutions. These are the exact analogs of the results valid in the case of local quasilinear degenerate equations established by Boccardo and Gallouët (J Funct Anal 87:149-169, 1989, Partial Differ Equ 17:641-655, 1992) and Kilpeläinen and Malý (Ann Scuola Norm Sup Pisa Cl Sci (IV) 19:591-613, 1992, Acta Math 172:137-161, 1994). As a consequence, we establish a number of results that can be considered as basic building blocks for a nonlocal, nonlinear potential theory: fine properties of solutions, Calderón-Zygmund estimates, continuity and boundedness criteria are established via Wolff potentials. A main tool is the introduction of a global excess functional that allows us to prove a nonlocal analog of the classical theory due to Campanato (Ann Mat Pura Appl (IV) 69:321-381, 1965). Our results cover the case of linear nonlocal equations with measurable coefficients, and the one of the fractional Laplacean, and are new already in such cases.

  2. Nonlocal electrical diffusion equation

    NASA Astrophysics Data System (ADS)

    Gómez-Aguilar, J. F.; Escobar-Jiménez, R. F.; Olivares-Peregrino, V. H.; Benavides-Cruz, M.; Calderón-Ramón, C.

    2016-07-01

    In this paper, we present an analysis and modeling of the electrical diffusion equation using the fractional calculus approach. This alternative representation for the current density is expressed in terms of the Caputo derivatives, the order for the space domain is 0<β≤1 and for the time domain is 0<γ≤2. We present solutions for the full fractional equation involving space and time fractional derivatives using numerical methods based on Fourier variable separation. The case with spatial fractional derivatives leads to Levy flight type phenomena, while the time fractional equation is related to sub- or super diffusion. We show that the mathematical concept of fractional derivatives can be useful to understand the behavior of semiconductors, the design of solar panels, electrochemical phenomena and the description of anomalous complex processes.

  3. A dispersive wave equation using nonlocal elasticity

    NASA Astrophysics Data System (ADS)

    Challamel, Noël; Rakotomanana, Lalaonirina; Le Marrec, Loïc

    2009-08-01

    Nonlocal continuum mechanics allows one to account for the small length scale effect that becomes significant when dealing with micro- or nano-structures. This Note investigates a model of wave propagation in a nonlocal elastic material. We show that a dispersive wave equation is obtained from a nonlocal elastic constitutive law, based on a mixture of a local and a nonlocal strain. This model comprises both the classical gradient model and the Eringen's integral model. The dynamic properties of the model are discussed, and corroborate well some recent theoretical studies published to unify both static and dynamics gradient elasticity theories. Moreover, an excellent matching of the dispersive curve of the Born-Kármán model of lattice dynamics is obtained with such nonlocal model. To cite this article: N. Challamel et al., C. R. Mecanique 337 (2009).

  4. Chaotic Orbits for Systems of Nonlocal Equations

    NASA Astrophysics Data System (ADS)

    Dipierro, Serena; Patrizi, Stefania; Valdinoci, Enrico

    2016-07-01

    We consider a system of nonlocal equations driven by a perturbed periodic potential. We construct multibump solutions that connect one integer point to another one in a prescribed way. In particular, heteroclinic, homoclinic and chaotic trajectories are constructed. This is the first attempt to consider a nonlocal version of this type of dynamical systems in a variational setting and the first result regarding symbolic dynamics in a fractional framework.

  5. Nonlocalization of Nonlocal Symmetry and Symmetry Reductions of the Burgers Equation

    NASA Astrophysics Data System (ADS)

    Jin, Yan; Jia, Man; Lou, Sen-Yue

    2012-12-01

    Symmetry reduction method is one of the best ways to find exact solutions. In this paper, we study the possibility of symmetry reductions of the well known Burgers equation including the nonlocal symmetry. The related new group invariant solutions are obtained. Especially, the interactions among solitons, Airy waves, and Kummer waves are explicitly given.

  6. Symmetries and nonlocal conservation laws of the general magma equation

    NASA Astrophysics Data System (ADS)

    Khamitova, Raisa

    2009-11-01

    In this paper the general magma equation modelling a melt flow in the Earth's mantle is discussed. Applying the new theorem on nonlocal conservation laws [Ibragimov NH. A new conservation theorem. J Math Anal Appl 2007;333(1):311-28] and using the symmetries of the model equation nonlocal conservation laws are computed. In accordance with Ibragimov [Ibragimov NH. Quasi-self-adjoint differential equations. Preprint in Archives of ALGA, vol. 4, BTH, Karlskrona, Sweden: Alga Publications; 2007. p. 55-60, ISSN: 1652-4934] it is shown that the general magma equation is quasi-self-adjoint for arbitrary m and n and self-adjoint for n = -m. These important properties are used for deriving local conservation laws.

  7. Solution of K-V envelope equations

    SciTech Connect

    Anderson, O.A.

    1995-04-01

    The envelope equations for a KV beam with space charge have been analyzed systematically by an e expansion followed by integrations. The focusing profile as a function of axial length is assumed to be symmetric but otherwise arbitrary. Given the bean current, emittance, and peak focusing field, we find the envelopes a(s) and b(s) and obtain , a{sub max}, {sigma}, and {sigma}{sub 0}. Explicit results are presented for various truncations of the expansion. The zeroth order results correspond to those from the well-known smooth approximation; the same convenient format is retained for the higher order cases. The first order results, involving single correction terms, give 3--10 times better accuracy and are good to {approximately}1% at {sigma}{sub 0} = 70{degree}. Third order gives a factor of 10--30 improvement over the smooth approximation and derived quantities accurate to {approximately}1% at {sigma}{sub 0} = 112 {degree}. The first order expressions are convenient design tools. They lend themselves to variable energy problems and have been applied to the design, construction, and testing of ESQ accelerators at LBL.

  8. On a class of nonlocal wave equations from applications

    NASA Astrophysics Data System (ADS)

    Beyer, Horst Reinhard; Aksoylu, Burak; Celiker, Fatih

    2016-06-01

    We study equations from the area of peridynamics, which is a nonlocal extension of elasticity. The governing equations form a system of nonlocal wave equations. We take a novel approach by applying operator theory methods in a systematic way. On the unbounded domain ℝn, we present three main results. As main result 1, we find that the governing operator is a bounded function of the governing operator of classical elasticity. As main result 2, a consequence of main result 1, we prove that the peridynamic solutions strongly converge to the classical solutions by utilizing, for the first time, strong resolvent convergence. In addition, main result 1 allows us to incorporate local boundary conditions, in particular, into peridynamics. This avenue of research is developed in companion papers, providing a remedy for boundary effects. As main result 3, employing spherical Bessel functions, we give a new practical series representation of the solution which allows straightforward numerical treatment with symbolic computation.

  9. Nonlocalized modulation of periodic reaction diffusion waves: The Whitham equation

    NASA Astrophysics Data System (ADS)

    Johnson, Mathew A.; Noble, Pascal; Rodrigues, L. Miguel; Zumbrun, Kevin

    2013-02-01

    In a companion paper, we established nonlinear stability with detailed diffusive rates of decay of spectrally stable periodic traveling-wave solutions of reaction diffusion systems under small perturbations consisting of a nonlocalized modulation plus a localized ( L 1) perturbation. Here, we determine time-asymptotic behavior under such perturbations, showing that solutions consist of a leading order of a modulation whose parameter evolution is governed by an associated Whitham averaged equation.

  10. Fault diagnosis of rolling bearing based on fast nonlocal means and envelop spectrum.

    PubMed

    Lv, Yong; Zhu, Qinglin; Yuan, Rui

    2015-01-01

    The nonlocal means (NL-Means) method that has been widely used in the field of image processing in recent years effectively overcomes the limitations of the neighborhood filter and eliminates the artifact and edge problems caused by the traditional image denoising methods. Although NL-Means is very popular in the field of 2D image signal processing, it has not received enough attention in the field of 1D signal processing. This paper proposes a novel approach that diagnoses the fault of a rolling bearing based on fast NL-Means and the envelop spectrum. The parameters of the rolling bearing signals are optimized in the proposed method, which is the key contribution of this paper. This approach is applied to the fault diagnosis of rolling bearing, and the results have shown the efficiency at detecting roller bearing failures. PMID:25585105

  11. Fault Diagnosis of Rolling Bearing Based on Fast Nonlocal Means and Envelop Spectrum

    PubMed Central

    Lv, Yong; Zhu, Qinglin; Yuan, Rui

    2015-01-01

    The nonlocal means (NL-Means) method that has been widely used in the field of image processing in recent years effectively overcomes the limitations of the neighborhood filter and eliminates the artifact and edge problems caused by the traditional image denoising methods. Although NL-Means is very popular in the field of 2D image signal processing, it has not received enough attention in the field of 1D signal processing. This paper proposes a novel approach that diagnoses the fault of a rolling bearing based on fast NL-Means and the envelop spectrum. The parameters of the rolling bearing signals are optimized in the proposed method, which is the key contribution of this paper. This approach is applied to the fault diagnosis of rolling bearing, and the results have shown the efficiency at detecting roller bearing failures. PMID:25585105

  12. Exact solutions of fractional Schroedinger-like equation with a nonlocal term

    SciTech Connect

    Jiang Xiaoyun; Xu Mingyu; Qi Haitao

    2011-04-15

    We study the time-space fractional Schroedinger equation with a nonlocal potential. By the method of Fourier transform and Laplace transform, the Green function, and hence the wave function, is expressed in terms of H-functions. Graphical analysis demonstrates that the influence of both the space-fractal parameter {alpha} and the nonlocal parameter {nu} on the fractional quantum system is strong. Indeed, the nonlocal potential may act similar to a fractional spatial derivative as well as fractional time derivative.

  13. Improved Envelope And Centroid Equations for High Current Beams

    NASA Astrophysics Data System (ADS)

    Genoni, Thomas C.; Hughes, Thomas P.

    2002-04-01

    The standard envelope equation for electron beams (e.g., Lee-Cooper), neglects self-field contributions from the beam rotation and the slope of the beam envelope. We have carried out an expansion which includes these effects to first order, resulting in a new equation for the beam edge radius. The change in beam kinetic energy due to spacecharge depression as the beam radius varies is also included. For the centroid equation, we have included the "self-steering" effect due to the curvature of the beam orbit. To leading order, there is a cancellation between the self-steering effect and the spacecharge depression of the beam energy, so that a more accurate centroid equation is obtained by using the undepressed value of the energy (i.e., the total beam energy) to calculate the orbit. We have implemented the envelope and centroid equations in the LAMDA code. The effect of the new terms will be illustrated with calculations for the DARHT accelerators at Los Alamos National Laboratory.

  14. Improved Envelope and Centroid Equations for High Current Beams

    NASA Astrophysics Data System (ADS)

    Genoni, Thomas C.; Hughes, Thomas P.; Thoma, Carsten H.

    2002-12-01

    The standard envelope equation for charged particle beams (e.g., Lee-Cooper) neglects self-field contributions from the beam rotation and the slope of the beam envelope. We have carried out an expansion that includes these effects to first order, resulting in a new equation for the edge radius. The change in beam kinetic energy due to space-charge depression as the beam radius varies is also included. For the centroid equation, we have included the "self-steering" effect due to the curvature of the beam orbit. To leading order, there is a cancellation between the self-steering effect and the space-charge depression of the beam energy, so that a more accurate centroid equation is obtained by using the undepressed value of the energy (i.e., the total beam energy) to calculate the orbit. We have implemented the envelope and centroid equations in the Lamda code [1]. The effect of the new terms will be illustrated with calculations for the DARHT accelerators at the Los Alamos National Laboratory [2].

  15. Nonlocal operators, parabolic-type equations, and ultrametric random walks

    SciTech Connect

    Chacón-Cortes, L. F. Zúñiga-Galindo, W. A.

    2013-11-15

    In this article, we introduce a new type of nonlocal operators and study the Cauchy problem for certain parabolic-type pseudodifferential equations naturally associated to these operators. Some of these equations are the p-adic master equations of certain models of complex systems introduced by Avetisov, V. A. and Bikulov, A. Kh., “On the ultrametricity of the fluctuation dynamicmobility of protein molecules,” Proc. Steklov Inst. Math. 265(1), 75–81 (2009) [Tr. Mat. Inst. Steklova 265, 82–89 (2009) (Izbrannye Voprosy Matematicheskoy Fiziki i p-adicheskogo Analiza) (in Russian)]; Avetisov, V. A., Bikulov, A. Kh., and Zubarev, A. P., “First passage time distribution and the number of returns for ultrametric random walks,” J. Phys. A 42(8), 085003 (2009); Avetisov, V. A., Bikulov, A. Kh., and Osipov, V. A., “p-adic models of ultrametric diffusion in the conformational dynamics of macromolecules,” Proc. Steklov Inst. Math. 245(2), 48–57 (2004) [Tr. Mat. Inst. Steklova 245, 55–64 (2004) (Izbrannye Voprosy Matematicheskoy Fiziki i p-adicheskogo Analiza) (in Russian)]; Avetisov, V. A., Bikulov, A. Kh., and Osipov, V. A., “p-adic description of characteristic relaxation in complex systems,” J. Phys. A 36(15), 4239–4246 (2003); Avetisov, V. A., Bikulov, A. H., Kozyrev, S. V., and Osipov, V. A., “p-adic models of ultrametric diffusion constrained by hierarchical energy landscapes,” J. Phys. A 35(2), 177–189 (2002); Avetisov, V. A., Bikulov, A. Kh., and Kozyrev, S. V., “Description of logarithmic relaxation by a model of a hierarchical random walk,” Dokl. Akad. Nauk 368(2), 164–167 (1999) (in Russian). The fundamental solutions of these parabolic-type equations are transition functions of random walks on the n-dimensional vector space over the field of p-adic numbers. We study some properties of these random walks, including the first passage time.

  16. A note on the nonlocal boundary value problem for a third order partial differential equation

    NASA Astrophysics Data System (ADS)

    Belakroum, Kheireddine; Ashyralyev, Allaberen; Guezane-Lakoud, Assia

    2016-08-01

    The nonlocal boundary-value problem for a third order partial differential equation d/3u (t ) d t3 +A d/u (t ) d t =f (t ), 0 nonlocal boundary value problem is established. In applications, the stability estimates for the solution of three nonlocal boundary value problems for the third order partial differential equations are obtained.

  17. New Exact Solutions of the CDGSK Equation Related to a Non-local Symmetry

    NASA Astrophysics Data System (ADS)

    Lou, Senyue; Ruan, Hangyu; Chen, Weizhong; Wang, Zhenli; Chen, Lili

    1994-10-01

    A non-local symmetry of the Caudrey-Dodd-Gibbon-Sawada-Kotera (CDGSK) equation has been used for finding exact solution in two different ways. Firstly, using the standard prolongation approach, we obtain the finite Lie Bäcklund transformation and the single soliton solution. Secondly, combining some local symmetries and the nonlocal symmetry, we get the group invariant solution which is described by the Weierstrass elliptic function and is deduced to the so-called interacting soliton for a special parameter.

  18. Imaginary Time Step Method to Solve the Dirac Equation with Nonlocal Potential

    SciTech Connect

    Zhang Ying; Liang Haozhao; Meng Jie

    2009-08-26

    The imaginary time step (ITS) method is applied to solve the Dirac equation with nonlocal potentials in coordinate space. Taking the nucleus {sup 12}C as an example, even with nonlocal potentials, the direct ITS evolution for the Dirac equation still meets the disaster of the Dirac sea. However, following the recipe in our former investigation, the disaster can be avoided by the ITS evolution for the corresponding Schroedinger-like equation without localization, which gives the convergent results exactly the same with those obtained iteratively by the shooting method with localized effective potentials.

  19. Interaction solutions for mKP equation with nonlocal symmetry reductions and CTE method

    NASA Astrophysics Data System (ADS)

    Ren, Bo

    2015-06-01

    The nonlocal symmetries for the modified Kadomtsev-Petviashvili (mKP) equation are obtained with the truncated Painlevé method. The nonlocal symmetries can be localized to the Lie point symmetries by introducing auxiliary dependent variables. The finite symmetry transformations and similarity reductions related with the nonlocal symmetries are computed. The multi-solitary wave solution and interaction solutions among a soliton and cnoidal waves of the mKP equation are presented. In the meantime, the consistent tanh expansion method is applied to the mKP equation. The explicit interaction solutions among a soliton and other types of nonlinear waves such as cnoidal periodic waves and multiple resonant soliton solutions are given.

  20. Asymptotic reductions and solitons of nonlocal nonlinear Schrödinger equations

    NASA Astrophysics Data System (ADS)

    Horikis, Theodoros P.; Frantzeskakis, Dimitrios J.

    2016-05-01

    Asymptotic reductions of a defocusing nonlocal nonlinear Schrödinger model in (3 + 1)-dimensions, in both Cartesian and cylindrical geometry, are presented. First, at an intermediate stage, a Boussinesq equation is derived, and then its far-field, in the form of a variety of Kadomtsev–Petviashvilli (KP) equations for right- and left-going waves, is found. KP models include versions of the KP-I and KP-II equations, in Cartesian and cylindrical geometry. Solitary waves solutions, planar or ring-shaped, and of dark or anti-dark type, are also predicted to occur. Their nature and stability is determined by a parameter defined by the physical parameters of the original nonlocal system. It is thus found that (dark) anti-dark solitary waves are only supported by a weak (strong) nonlocality, and are unstable (stable) in higher-dimensions. Our analytical predictions are corroborated by direct numerical simulations.

  1. CTE Solvability, Exact Solutions and Nonlocal Symmetries of the Sharma-Tasso-Olver Equation

    NASA Astrophysics Data System (ADS)

    Pu, Huan; Jia, Man

    2015-12-01

    In this letter, we prove that the STO equation is CTE solvable and obtain the exact solutions of solitons fission and fusion. We also provide the nonlocal symmetries of the STO equation related to CTE. The nonlocal symmetries are localized by prolonging the related enlarged system. Supported by National Natural Science Foundation of China under Grant Nos. 11205092, 11175092 and 11435005, Ningbo Natural Science Foundation under Grant Nos. 2015A610159 and 2012A610178 and by the Opening Project of Zhejiang Provincial Top Key Discipline of Physics Sciences in Ningbo University under Grant No. xkzw11502. And the authors were sponsored by K. C. Wong Magna Fund in Ningbo University

  2. Nonlocal Symmetry Reductions, CTE Method and Exact Solutions for Higher-Order KdV Equation

    NASA Astrophysics Data System (ADS)

    Ren, Bo; Liu, Xi-Zhong; Liu, Ping

    2015-02-01

    The nonlocal symmetries for the higher-order KdV equation are obtained with the truncated Painlevé method. The nonlocal symmetries can be localized to the Lie point symmetries by introducing suitable prolonged systems. The finite symmetry transformations and similarity reductions for the prolonged systems are computed. Moreover, the consistent tanh expansion (CTE) method is applied to the higher-order KdV equation. These methods lead to some novel exact solutions of the higher-order KdV system.

  3. Dynamical Behavior of Solution in Integrable Nonlocal Lakshmanan—Porsezian—Daniel Equation

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Qiu, De-Qin; Wu, Zhi-Wei; He, Jing-Song

    2016-06-01

    The integrable nonlocal Lakshmanan—Porsezian—Daniel (LPD) equation which has the higher-order terms (dispersions and nonlinear effects) is first introduced. We demonstrate the integrability of the nonlocal LPD equation, provide its Lax pair, and present its rational soliton solutions and self-potential function by using the degenerate Darboux transformation. From the numerical plots of solutions, the compression effects of the real refractive index profile and the gain-or-loss distribution produced by δ are discussed. Supported by the National Natural Science Foundation of China under Grant No. 11271210 and the K.C. Wong Magna Fund in Ningbo University

  4. Nonlocal growth equations-a test case for dynamic renormalization group analysis

    NASA Astrophysics Data System (ADS)

    Schwartz, Moshe; Katzav, Eytan

    2003-12-01

    In this paper we discuss nonlocal growth equations such as the generalization of the Kardar-Parisi-Zhang (KPZ) equation that includes long-range interactions, also known as the Nonlocal-Kardar-Parisi-Zhang (NKPZ) equation, and the nonlocal version of the molecular-beam-epitaxy (NMBE) equation. We show that the steady-state strong coupling solution for nonlocal models such as NKPZ and NMBE can be obtained exactly in one dimension for some special cases, using the Fokker-Planck form of these equations. The exact results we derive do not agree with previous results obtained by Dynamic Renormalization Group (DRG) analysis. This discrepancy is important because DRG is a common method used extensively to deal with nonlinear field equations. While difficulties with this method for d>1 has been realized in the past, it has been believed so far that DRG is still safe in one dimension. Our result shows differently. The reasons for the failure of DRG to recover the exact one-dimensional results are also discussed.

  5. Solution of the three-dimensional Helmholtz equation with nonlocal boundary conditions

    NASA Technical Reports Server (NTRS)

    Hodge, Steve L.; Zorumski, William E.; Watson, Willie R.

    1995-01-01

    The Helmholtz equation is solved within a three-dimensional rectangular duct with a nonlocal radiation boundary condition at the duct exit plane. This condition accurately models the acoustic admittance at an arbitrarily-located computational boundary plane. A linear system of equations is constructed with second-order central differences for the Helmholtz operator and second-order backward differences for both local admittance conditions and the gradient term in the nonlocal radiation boundary condition. The resulting matrix equation is large, sparse, and non-Hermitian. The size and structure of the matrix makes direct solution techniques impractical; as a result, a nonstationary iterative technique is used for its solution. The theory behind the nonstationary technique is reviewed, and numerical results are presented for radiation from both a point source and a planar acoustic source. The solutions with the nonlocal boundary conditions are invariant to the location of the computational boundary, and the same nonlocal conditions are valid for all solutions. The nonlocal conditions thus provide a means of minimizing the size of three-dimensional computational domains.

  6. Nonlocal Symmetry and Interaction Solutions of a Generalized Kadomtsev—Petviashvili Equation

    NASA Astrophysics Data System (ADS)

    Huang, Li-Li; Chen, Yong; Ma, Zheng-Yi

    2016-08-01

    A generalized Kadomtsev—Petviashvili equation is studied by nonlocal symmetry method and consistent Riccati expansion (CRE) method in this paper. Applying the truncated Painlevé analysis to the generalized Kadomtsev—Petviashvili equation, some Bäcklund transformations (BTs) including auto-BT and non-auto-BT are obtained. The auto-BT leads to a nonlocal symmetry which corresponds to the residual of the truncated Painlevé expansion. Then the nonlocal symmetry is localized to the corresponding nonlocal group by introducing two new variables. Further, by applying the Lie point symmetry method to the prolonged system, a new type of finite symmetry transformation is derived. In addition, the generalized Kadomtsev—Petviashvili equation is proved consistent Riccati expansion (CRE) solvable. As a result, the soliton-cnoidal wave interaction solutions of the equation are explicitly given, which are difficult to be found by other traditional methods. Moreover, figures are given out to show the properties of the explicit analytic interaction solutions. Supported by the Global Change Research Program of China under Grant No. 2015CB953904, National Natural Science Foundation of under Grant Nos. 11275072 and 11435005, Doctoral Program of Higher Education of China under Grant No. 20120076110024, the Network Information Physics Calculation of Basic Research Innovation Research Group of China under Grant No. 61321064, and Shanghai Collaborative Innovation Center of Trustworthy Software for Internet of Things under Grant No. ZF1213, and Zhejiang Provincial Natural Science Foundation of China under Grant No. LY14A010005

  7. Asymptotics semiclassically concentrated on curves for the nonlocal Fisher–Kolmogorov–Petrovskii–Piskunov equation

    NASA Astrophysics Data System (ADS)

    Levchenko, E. A.; Shapovalov, A. V.; Trifonov, A. Yu

    2016-07-01

    In this paper we construct asymptotic solutions for the nonlocal multidimensional Fisher–Kolmogorov–Petrovskii–Piskunov equation in the class of functions concentrated on a one-dimensional manifold (curve) using a semiclassical approximation technique. We show that the construction of these solutions can be reduced to solving a similar problem for the nonlocal Fisher–Kolmogorov–Petrovskii–Piskunov in the class of functions concentrated at a point (zero-dimensional manifold) together with an additional operator condition. The general approach is exemplified by constructing a two-dimensional two-parametric solution, which describes quasi-steady-state patterns on a circumference.

  8. Nonlocal Symmetries, Explicit Solutions, and Wave Structures for the Korteweg-de Vries Equation

    NASA Astrophysics Data System (ADS)

    Ma, Zheng-Yi; Fei, Jin-Xi

    2016-08-01

    From the known Lax pair of the Korteweg-de Vries (KdV) equation, the Lie symmetry group method is successfully applied to find exact invariant solutions for the KdV equation with nonlocal symmetries by introducing two suitable auxiliary variables. Meanwhile, based on the prolonged system, the explicit analytic interaction solutions related to the hyperbolic and Jacobi elliptic functions are derived. Figures show the physical interaction between the cnoidal waves and a solitary wave.

  9. Towards a gauge-equivalent magnetic structure of the nonlocal nonlinear Schrödinger equation

    NASA Astrophysics Data System (ADS)

    Gadzhimuradov, T. A.; Agalarov, A. M.

    2016-06-01

    It is shown that the nonlocal nonlinear Schrödinger equation recently proposed by Ablowitz and Musslimani [Phys. Rev. Lett. 110, 064105 (2013), 10.1103/PhysRevLett.110.064105] is gauge equivalent to the unconventional system of coupled Landau-Lifshitz equations. The first integrals of motion and one-soliton solution of an obtained model are given. The physical and geometrical aspects of model and their effect on expected metamagnetic structures are studied.

  10. Modulational instability in nonlinear nonlocal equations of regularized long wave type

    NASA Astrophysics Data System (ADS)

    Hur, Vera Mikyoung; Pandey, Ashish Kumar

    2016-06-01

    We study the stability and instability of periodic traveling waves in the vicinity of the origin in the spectral plane, for equations of Benjamin-Bona-Mahony (BBM) and regularized Boussinesq types permitting nonlocal dispersion. We extend recent results for equations of Korteweg-de Vries type and derive modulational instability indices as functions of the wave number of the underlying wave. We show that a sufficiently small, periodic traveling wave of the BBM equation is spectrally unstable to long wavelength perturbations if the wave number is greater than a critical value and a sufficiently small, periodic traveling wave of the regularized Boussinesq equation is stable to square integrable perturbations.

  11. Nonlocal Symmetry and its Applications in Perturbed mKdV Equation

    NASA Astrophysics Data System (ADS)

    Ren, Bo; Lin, Ji

    2016-06-01

    Based on the modified direct method, the variable-coefficient perturbed mKdV equation is changed to the constant-coefficient perturbed mKdV equation. The truncated Painlevé method is applied to obtain the nonlocal symmetry of the constant-coefficient perturbed mKdV equation. By introducing one new dependent variable, the nonlocal symmetry can be localized to the Lie point symmetry. Thanks to the localization procedure, the finite symmetry transformation is presented by solving the initial value problem of the prolonged systems. Furthermore, many explicit interaction solutions among different types of solutions such as solitary waves, rational solutions, and Painlevé II solutions are obtained using the symmetry reduction method to the enlarged systems. Two special concrete soliton-cnoidal interaction solutions are studied in both analytical and graphical ways.

  12. Tolman-Oppenheimer-Volkoff equations in nonlocal f(R) gravity

    NASA Astrophysics Data System (ADS)

    Momeni, Davood; Gholizade, H.; Raza, Muhammad; Myrzakulov, Ratbay

    2015-06-01

    Nonlocal f(R) gravity was proposed as a powerful alternative to general relativity (GR). This theory has potentially adverse implications for infrared (IR) regime as well as ultraviolet (UV) early epochs. However, there are a lot of powerful features, making it really user-friendly. A scalar-tensor frame comprising two auxiliary scalar fields is used to reduce complex action. However, this is not the case for the modification complex which plays a distinct role in modified theories for gravity. In this work, we study the dynamics of a static, spherically symmetric object. The interior region of space-time had rapidly filled the perfect fluid. However, it is possible to derive a physically based model which relates interior metric to nonlocal f(R). The Tolman-Oppenheimer-Volkoff (TOV) equations would be a set of first-order differential equations from which we can deduce all mathematical (physical) truths and derive all dynamical objects. This set of dynamical equations govern pressure p, density ρ, mass m and auxiliary fields {ψ, ξ}. The full conditional solutions are evaluated and inverted numerically to obtain exact forms of the compact stars Her X-1, SAX J 1808.4-3658 and 4U 1820-30 for nonlocal Starobinsky model of f(◻-1 R) = ◻-1 R+α(◻-1 R)2. The program solves the differential equations numerically using adaptive Gaussian quadrature. An ascription of correctness is supposed to be an empirical equation of state (P)/(Pc) = a (1- e-bρ/ρc) for star which is informative in so far as it excludes an alternative nonlocal approach to compact star formation. This model is most suited for astrophysical observation.

  13. A Legendre tau-Spectral Method for Solving Time-Fractional Heat Equation with Nonlocal Conditions

    PubMed Central

    Bhrawy, A. H.; Alghamdi, M. A.

    2014-01-01

    We develop the tau-spectral method to solve the time-fractional heat equation (T-FHE) with nonlocal condition. In order to achieve highly accurate solution of this problem, the operational matrix of fractional integration (described in the Riemann-Liouville sense) for shifted Legendre polynomials is investigated in conjunction with tau-spectral scheme and the Legendre operational polynomials are used as the base function. The main advantage in using the presented scheme is that it converts the T-FHE with nonlocal condition to a system of algebraic equations that simplifies the problem. For demonstrating the validity and applicability of the developed spectral scheme, two numerical examples are presented. The logarithmic graphs of the maximum absolute errors is presented to achieve the exponential convergence of the proposed method. Comparing between our spectral method and other methods ensures that our method is more accurate than those solved similar problem. PMID:25057507

  14. A Widder's Type Theorem for the Heat Equation with Nonlocal Diffusion

    NASA Astrophysics Data System (ADS)

    Barrios, Begoña; Peral, Ireneo; Soria, Fernando; Valdinoci, Enrico

    2014-08-01

    The main goal of this work is to prove that every non-negative strong solution u( x, t) to the problem can be written as where and This result shows uniqueness in the setting of non-negative solutions and extends some classical results for the heat equation by Widder in [15] to the nonlocal diffusion framework.

  15. Positive or sign-changing solutions for a critical semilinear nonlocal equation

    NASA Astrophysics Data System (ADS)

    Long, Wei; Yang, Jing

    2016-06-01

    We consider the following critical semilinear nonlocal equation involving the fractional Laplacian (-Δ)su = K(|x|)|u|^{2^{*}s-2}u,quad in {R}^N, where {K(|x|)} is a positive radial function, {N > 2 + 2s, 0 < s < 1}, and {2^{*}s = 2N/N-2s}. Under some asymptotic assumptions on K( x) at an extreme point, we show that this problem has infinitely many nonradial positive or sign-changing solutions.

  16. Global stability of travelling wave fronts for non-local diffusion equations with delay

    NASA Astrophysics Data System (ADS)

    Wang, X.; Lv, G.

    2014-04-01

    This paper is concerned with the global stability of travelling wave fronts for non-local diffusion equations with delay. We prove that the non-critical travelling wave fronts are globally exponentially stable under perturbations in some exponentially weighted L^\\infty-spaces. Moreover, we obtain the decay rates of \\sup_{x\\in{R}}\\vert u(x,t)-\\varphi(x+ct)\\vert using weighted energy estimates.

  17. Monotone waves for non-monotone and non-local monostable reaction-diffusion equations

    NASA Astrophysics Data System (ADS)

    Trofimchuk, Elena; Pinto, Manuel; Trofimchuk, Sergei

    2016-07-01

    We propose a new approach for proving existence of monotone wavefronts in non-monotone and non-local monostable diffusive equations. This allows to extend recent results established for the particular case of equations with local delayed reaction. In addition, we demonstrate the uniqueness (modulo translations) of obtained monotone wavefront within the class of all monotone wavefronts (such a kind of conditional uniqueness was recently established for the non-local KPP-Fisher equation by Fang and Zhao). Moreover, we show that if delayed reaction is local then each monotone wavefront is unique (modulo translations) within the class of all non-constant traveling waves. Our approach is based on the construction of suitable fundamental solutions for linear integral-differential equations. We consider two alternative scenarios: in the first one, the fundamental solution is negative (typically holds for the Mackey-Glass diffusive equations) while in the second one, the fundamental solution is non-negative (typically holds for the KPP-Fisher diffusive equations).

  18. Nonlocal symmetry and exact solutions of the (2+1)-dimensional modified Bogoyavlenskii–Schiff equation

    NASA Astrophysics Data System (ADS)

    Li-Li, Huang; Yong, Chen

    2016-06-01

    In this paper, the truncated Painlevé analysis, nonlocal symmetry, Bäcklund transformation of the (2+1)-dimensional modified Bogoyavlenskii–Schiff equation are presented. Then the nonlocal symmetry is localized to the corresponding nonlocal group by the prolonged system. In addition, the (2+1)-dimensional modified Bogoyavlenskii–Schiff is proved consistent Riccati expansion (CRE) solvable. As a result, the soliton–cnoidal wave interaction solutions of the equation are explicitly given, which are difficult to find by other traditional methods. Moreover figures are given out to show the properties of the explicit analytic interaction solutions. Project supported by the Global Change Research Program of China (Grant No. 2015CB953904), the National Natural Science Foundation of China (Grant Nos. 11275072 and 11435005), the Doctoral Program of Higher Education of China (Grant No. 20120076110024), the Network Information Physics Calculation of Basic Research Innovation Research Group of China (Grant No. 61321064), and the Fund from Shanghai Collaborative Innovation Center of Trustworthy Software for Internet of Things (Grant No. ZF1213).

  19. Internal noise-driven generalized Langevin equation from a nonlocal continuum model.

    PubMed

    Sarkar, Saikat; Chowdhury, Shubhankar Roy; Roy, Debasish; Vasu, Ram Mohan

    2015-08-01

    Starting with a micropolar formulation, known to account for nonlocal microstructural effects at the continuum level, a generalized Langevin equation (GLE) for a particle, describing the predominant motion of a localized region through a single displacement degree of freedom, is derived. The GLE features a memory-dependent multiplicative or internal noise, which appears upon recognizing that the microrotation variables possess randomness owing to an uncertainty principle. Unlike its classical version, the present GLE qualitatively reproduces the experimentally measured fluctuations in the steady-state mean square displacement of scattering centers in a polyvinyl alcohol slab. The origin of the fluctuations is traced to nonlocal spatial interactions within the continuum, a phenomenon that is ubiquitous across a broad class of response regimes in solids and fluids. This renders the proposed GLE a potentially useful model in such cases. PMID:26382386

  20. Internal noise-driven generalized Langevin equation from a nonlocal continuum model

    NASA Astrophysics Data System (ADS)

    Sarkar, Saikat; Chowdhury, Shubhankar Roy; Roy, Debasish; Vasu, Ram Mohan

    2015-08-01

    Starting with a micropolar formulation, known to account for nonlocal microstructural effects at the continuum level, a generalized Langevin equation (GLE) for a particle, describing the predominant motion of a localized region through a single displacement degree of freedom, is derived. The GLE features a memory-dependent multiplicative or internal noise, which appears upon recognizing that the microrotation variables possess randomness owing to an uncertainty principle. Unlike its classical version, the present GLE qualitatively reproduces the experimentally measured fluctuations in the steady-state mean square displacement of scattering centers in a polyvinyl alcohol slab. The origin of the fluctuations is traced to nonlocal spatial interactions within the continuum, a phenomenon that is ubiquitous across a broad class of response regimes in solids and fluids. This renders the proposed GLE a potentially useful model in such cases.

  1. Standing wave and global existence to nonlocal nonlinear Schrödinger equations: the two-dimensional case

    NASA Astrophysics Data System (ADS)

    Gan, Zaihui

    2016-07-01

    In this paper, we consider the standing waves and the global existence for two-dimensional nonlocal nonlinear Schrödinger equations. It is a coupled system which describes the spontaneous generation of a magnetic field in a cold plasma under the static limit. The main difficulty in the proofs lies in exploring the inner structure of the equations due to the fact that the nonlocal terms violate the inner scaling invariance, which may cause the non-zero energy for the ground state. For this reason, we first make a proper use of the inner structure of the equations to establish the existence of standing waves, and then we apply an energy scaling to obtain the instability of standing waves. Finally we show a sharp threshold for the global existence of solutions to the nonlocal nonlinear Schrödinger equations by a variational method, which depends again on the inner structure of the equations under consideration.

  2. Microphase separation patterns in diblock copolymers on curved surfaces using a nonlocal Cahn-Hilliard equation.

    PubMed

    Jeong, Darae; Kim, Junseok

    2015-11-01

    We investigate microphase separation patterns on curved surfaces in three-dimensional space by numerically solving a nonlocal Cahn-Hilliard equation for diblock copolymers. In our model, a curved surface is implicitly represented as the zero level set of a signed distance function. We employ a discrete narrow band grid that neighbors the curved surface. Using the closest point method, we apply a pseudo-Neumann boundary at the boundary of the computational domain. The boundary treatment allows us to replace the Laplace-Beltrami operator by the standard Laplacian operator. In particular, we can apply standard finite difference schemes in order to approximate the nonlocal Cahn-Hilliard equation in the discrete narrow band domain. We employ a type of unconditionally stable scheme, which was introduced by Eyre, and use the Jacobi iterative to solve the resulting implicit discrete system of equations. In addition, we use the minimum number of grid points for the discrete narrow band domain. Therefore, the algorithm is simple and fast. Numerous computational experiments are provided to study microphase separation patterns for diblock copolymers on curved surfaces in three-dimensional space. PMID:26577816

  3. Study of a family of higher order nonlocal degenerate parabolic equations: From the porous medium equation to the thin film equation

    NASA Astrophysics Data System (ADS)

    Tarhini, Rana

    2015-12-01

    In this paper, we study a nonlocal degenerate parabolic equation of order α + 2 for α ∈ (0, 2). The equation is a generalization of the one arising in the modeling of hydraulic fractures studied by Imbert and Mellet in 2011. Using the same approach, we prove the existence of solutions for this equation for 0 < α < 2 and for nonnegative initial data satisfying appropriate assumptions. The main difference is the compactness results due to different Sobolev embeddings. Furthermore, for α > 1, we construct a nonnegative solution for nonnegative initial data under weaker assumptions.

  4. Nonlocal diffusion problems that approximate a parabolic equation with spatial dependence

    NASA Astrophysics Data System (ADS)

    Molino, Alexis; Rossi, Julio D.

    2016-06-01

    In this paper, we show that smooth solutions to the Dirichlet problem for the parabolic equation v_t(x,t)=sum_{i,j=1}N a_{ij}(x)partial2v(x,t)/partial{xipartial{x}j} + sum_{i =1}N bi(x)partial{v}(x,t)/partial{x_i} qquad x in Ω, with v( x, t) = g( x, t), {x in partial Ω,} can be approximated uniformly by solutions of nonlocal problems of the form ut^{\\varepsilon}(x,t)=int_{mathbb{R}n} K_{\\varepsilon}(x,y)(u^{\\varepsilon}(y,t)-u^{\\varepsilon}(x,t))dy, quad x in Ω, with {u^{\\varepsilon}(x,t)=g(x,t)}, {x notin Ω}, as {\\varepsilon to 0}, for an appropriate rescaled kernel {K_{\\varepsilon}}. In this way, we show that the usual local evolution problems with spatial dependence can be approximated by nonlocal ones. In the case of an equation in divergence form, we can obtain an approximation with symmetric kernels, that is, {K_{\\varepsilon}(x,y) = K_{\\varepsilon}(y,x)}.

  5. Long-term behavior of reaction-diffusion equations with nonlocal boundary conditions on rough domains

    NASA Astrophysics Data System (ADS)

    Gal, Ciprian G.; Warma, Mahamadi

    2016-08-01

    We investigate the long term behavior in terms of finite dimensional global and exponential attractors, as time goes to infinity, of solutions to a semilinear reaction-diffusion equation on non-smooth domains subject to nonlocal Robin boundary conditions, characterized by the presence of fractional diffusion on the boundary. Our results are of general character and apply to a large class of irregular domains, including domains whose boundary is Hölder continuous and domains which have fractal-like geometry. In addition to recovering most of the existing results on existence, regularity, uniqueness, stability, attractor existence, and dimension, for the well-known reaction-diffusion equation in smooth domains, the framework we develop also makes possible a number of new results for all diffusion models in other non-smooth settings.

  6. Efficient computation of matched solutions of the KV envelope equations for periodic focusing lattices.

    SciTech Connect

    Lund, S M; Chilton, S H; Lee, E P

    2006-01-17

    A new iterative method is developed to numerically calculate the periodic, matched beam envelope solution of the coupled Kapchinskij-Vladimirskij (KV) equations describing the transverse evolution of a beam in a periodic, linear focusing lattice of arbitrary complexity. Implementation of the method is straightforward. It is highly convergent and can be applied to all usual parameterizations of the matched envelope solutions. The method is applicable to all classes of linear focusing lattices without skew couplings, and also applies to parameters where the matched beam envelope is strongly unstable. Example applications are presented for periodic solenoidal and quadrupole focusing lattices. Convergence properties are summarized over a wide range of system parameters.

  7. Analytic structure of two 1D-transport equations with nonlocal fluxes

    NASA Astrophysics Data System (ADS)

    Baker, Gregory R.; Li, Xiao; Morlet, Anne C.

    We replace the flux term in Burger's equation by two simple alternates that contain contributions depending globally on the solution. In one case, the term is in the form of a hyperbolic equation where the characteristic speed is nonlocal, and in the other the term is in conservation form. In both cases, the nonanalytic is due to the presence of the Hilbert transform. The equations have a loose analogy to the motion of vortex sheets. In particular, they both form singularities in finite time in the absence of viscous effects. Our motivation then is to study the influence of viscosity. In one case, viscosity does not prevent singularity formation. In the other, we can prove solutions exist for all time, and determine the likely weak solution as viscosity vanishes. An interesting aspect of our work is that singularity formation can be viewed as the motion of singularities in the complex physical plane that reach the real axis in finite time. In one case, the singularity is a pole and causes the solution to blow up when it reaches the real axis. In the other, numerical solutions and an asymptotic analysis suggest that the weak solution contains a square root singularity that reaches the real axis in finite time, and then propagates along it. We hope our results will spur further interest in the role of singularities in the complex spatial plane in solutions to transport equations.

  8. Fast-varying envelope transient equation for supercontinuum generation

    NASA Astrophysics Data System (ADS)

    Huang, Jing

    2016-01-01

    The transient nonlinear Schrodinger equation in which the frequency is a function of time is established to describe the fast-varying field in the process of supercontinuum generation. It is solved with two methods and validated by comparing its simulation results with those of reported experiments. Based on the simulations of this extended equation, it is also demonstrated that the second-order differential of the field to longitude (z) can be ignored in the supercontinuum generation, and the additive item caused by the relationship between frequency and time will induce a homogeneous frequency shift.

  9. Global existence for a nonlocal and nonlinear Fokker-Planck equation

    NASA Astrophysics Data System (ADS)

    Dreyer, Wolfgang; Huth, Robert; Mielke, Alexander; Rehberg, Joachim; Winkler, Michael

    2015-04-01

    We consider a Fokker-Planck equation on a compact interval where, as a constraint, the first moment is a prescribed function of time. Eliminating the associated Lagrange multiplier, one obtains nonlinear and nonlocal terms. After establishing suitable local existence results, we use the relative entropy as an energy functional. However, the time-dependent constraint leads to a source term such that a delicate analysis is needed to show that the dissipation terms are strong enough to control the work done by the constraint. We obtain global existence of solutions as long as the prescribed first moment stays in the interior of an interval. If the prescribed moment converges to a constant value inside the interior of the interval, then the solution stabilises to the unique steady state.

  10. Entire solutions of nonlocal dispersal equations with monostable nonlinearity in space periodic habitats

    NASA Astrophysics Data System (ADS)

    Li, Wan-Tong; Wang, Jia-Bing; Zhang, Li

    2016-08-01

    This paper is concerned with the new types of entire solutions other than traveling wave solutions of nonlocal dispersal equations with monostable nonlinearity in space periodic habitats. We first establish the existence and properties of spatially periodic solutions connecting two steady states. Then new types of entire solutions are constructed by combining the rightward and leftward pulsating traveling fronts with different speeds and a spatially periodic solution. Finally, for a class of special heterogeneous reaction, we further establish the uniqueness of entire solutions and the continuous dependence of such an entire solution on parameters, such as wave speeds and the shifted variables. In other words, we build a five-dimensional manifold of solutions and the traveling wave solutions are on the boundary of the manifold.

  11. Multivalley envelope function equations and effective potentials for phosphorus impurity in silicon

    NASA Astrophysics Data System (ADS)

    Klymenko, M. V.; Rogge, S.; Remacle, F.

    2015-11-01

    We propose a system of real-space envelope function equations without fitting parameters for modeling the electronic spectrum and wave functions of a phosphorus donor atom embedded in silicon. The approach relies on the Burt-Foreman envelope function representation and leads to coupled effective-mass Schrödinger equations containing smooth effective potentials. These potentials result from the spatial filtering imposed on the exact potential energy matrix elements in the envelope function representation. The corresponding filter function is determined from the definition of the envelope function. The resulting effective potentials and the system of envelope functions jointly reproduce the valley-orbit coupling effect in doped silicon. It is found that including the valley-orbit coupling not only of the 1 s but also for 2 s atomic orbitals, as well as static dielectric screening, is crucial to accurately reproduce experimental data. The measured binding energies are recovered with a maximum relative error of 1.53%. The computed wave functions are in good agreement with experimental measurements of the electron density provided by scanning tunneling microscopy.

  12. A non-local evolution equation model of cell–cell adhesion in higher dimensional space

    PubMed Central

    Dyson, Janet; Gourley, Stephen A.; Webb, Glenn F.

    2013-01-01

    A model for cell–cell adhesion, based on an equation originally proposed by Armstrong et al. [A continuum approach to modelling cell–cell adhesion, J. Theor. Biol. 243 (2006), pp. 98–113], is considered. The model consists of a nonlinear partial differential equation for the cell density in an N-dimensional infinite domain. It has a non-local flux term which models the component of cell motion attributable to cells having formed bonds with other nearby cells. Using the theory of fractional powers of analytic semigroup generators and working in spaces with bounded uniformly continuous derivatives, the local existence of classical solutions is proved. Positivity and boundedness of solutions is then established, leading to global existence of solutions. Finally, the asymptotic behaviour of solutions about the spatially uniform state is considered. The model is illustrated by simulations that can be applied to in vitro wound closure experiments. AMS Classifications: 35A01; 35B09; 35B40; 35K57; 92C17 PMID:23289870

  13. Existence and uniqueness of steady state solutions of a nonlocal diffusive logistic equation

    NASA Astrophysics Data System (ADS)

    Sun, Linan; Shi, Junping; Wang, Yuwen

    2013-08-01

    In this paper, we consider a dynamical model of population biology which is of the classical Fisher type, but the competition interaction between individuals is nonlocal. The existence, uniqueness, and stability of the steady state solution of the nonlocal problem on a bounded interval with homogeneous Dirichlet boundary conditions are studied.

  14. Nontrivial solution for Schrödinger-Poisson equations involving a fractional nonlocal operator via perturbation methods

    NASA Astrophysics Data System (ADS)

    Feng, Xiaojing

    2016-06-01

    This paper focuses on the following Schrödinger-Poisson equations involving a fractional nonlocal operator -Δ u+u+φ u=f(x,u),&in {R}^3,(-Δ)^{α/2}φ=u^2,lim_{|x|to ∞}φ(x)=0,&in {R}^3, where {α in (1,2]}. Under certain assumptions, we obtain the existence of nontrivial solution of the above problem without compactness by using the methods of perturbation and the mountain pass theorem.

  15. A pseudo-spectral method for a non-local KdV-Burgers equation posed on R

    NASA Astrophysics Data System (ADS)

    de la Hoz, Francisco; Cuesta, Carlota M.

    2016-04-01

    In this paper, we present a new pseudo-spectral method to solve the initial value problem associated to a non-local KdV-Burgers equation involving a Caputo-type fractional derivative. The basic idea is, using an algebraic map, to transform the whole real line into a bounded interval where we can apply a Fourier expansion. Special attention is given to the correct computation of the fractional derivative in this setting.

  16. Local and global solution for a nonlocal Fokker-Planck equation related to the adaptive biasing force process

    NASA Astrophysics Data System (ADS)

    Alrachid, Houssam; Lelièvre, Tony; Talhouk, Raafat

    2016-05-01

    We prove global existence, uniqueness and regularity of the mild, Lp and classical solution of a non-linear Fokker-Planck equation arising in an adaptive importance sampling method for molecular dynamics calculations. The non-linear term is related to a conditional expectation, and is thus non-local. The proof uses tools from the theory of semigroups of linear operators for the local existence result, and an a priori estimate based on a supersolution for the global existence result.

  17. A Class Of Generalized Kapchinskij-Vladimirskij Solutions And Associated Envelope Equations For High-intensity Charged Particle Beams

    SciTech Connect

    Hong Qin and Ronald C. Davidson

    2012-04-25

    A class of generalized Kapchinskij-Vladimirskij solutions of the nonlinear Vlasov-Maxwell equations and the associated envelope equations for high-intensity beams in a periodic lattice is derived. It includes the classical Kapchinskij-Vladimirskij solution as a special case. For a given lattice, the distribution functions and the envelope equations are specified by eight free parameters. The class of solutions derived captures a wider range of dynamical envelope behavior for high-intensity beams, and thus provides a new theoretical tool to investigate the dynamics of high-intensity beams.

  18. Painlevé analysis, nonlocal symmetry and explicit interaction solutions for supersymmetric mKdVB equation

    NASA Astrophysics Data System (ADS)

    Ren, Bo

    2016-08-01

    The N = 1 supersymmetric mKdVB system is transformed to a coupled bosonic system by using the bosonization approach. By a singularity structure analysis, the bosonized supersymmetric mKdVB (BSmKdVB) equation admits the Painlevé property. Starting from the standard truncated Painlevé method, the nonlocal symmetry for the BSmKdVB equation is obtained. To solve the first Lie's principle related with the nonlocal symmetry, the nonlocal symmetry is localized to the Lie point symmetry by introducing multiple new fields. Thanks to localization processes, similarity reductions for the prolonged systems are studied by the Lie point symmetry method. The interaction solutions among solitons and other complicated waves including Painlevé II waves and periodic cnoidal waves are given through the reduction theorems. The soliton-cnoidal wave interaction solutions are explicitly given by using the mapping and deformation method. The concrete soliton-cnoidal interaction solutions are displayed both in analytical and graphical ways.

  19. A micromechanics-based nonlocal constitutive equation incorporating three-point statistics for random linear elastic composite materials

    NASA Astrophysics Data System (ADS)

    Drugan, W. J.; Willis, J. R.

    2016-06-01

    A variational formulation employing the minimum potential and complementary energy principles is used to derive a micromechanics-based nonlocal constitutive equation for random linear elastic composite materials, relating ensemble averages of stress and strain in the most general situation when mean fields vary spatially. All information contained in the energy principles is retained; we employ stress polarization trial fields utilizing one-point statistics so that the resulting nonlocal constitutive equation incorporates up through three-point statistics. The variational structure is developed first for arbitrary heterogeneous linear elastic materials, then for randomly inhomogeneous materials, then for general n-phase composite materials, and finally for two-phase composite materials, in which case explicit variational upper and lower bounds on the nonlocal effective modulus tensor operator are derived. For statistically uniform infinite-body composites, these bounds are determined even more explicitly in Fourier transform space. We evaluate these in detail in an example case: longitudinal shear of an aligned fiber or void composite. We determine the full permissible ranges of the terms involving two- and three-point statistics in these bounds, and thereby exhibit explicit results that encompass arbitrary isotropic in-plane phase distributions; we also develop a nonlocal "Milton parameter", the variation of whose eigenvalues throughout the interval [0, 1] describes the full permissible range of the three-point term. Example plots of the new bounds show them to provide substantial improvement over the (two-point) Hashin-Shtrikman bounds on the nonlocal operator tensor, for all permissible values of the two- and three-point parameters. We next discuss further applications of the general nonlocal operator bounds: to any three-dimensional scalar transport problem e.g. conductivity, for which explicit results are given encompassing the full permissible ranges of the

  20. Self-Consistent System of Equations for a Kinetic Description of the Low-Pressure Discharges Accounting for the Nonlocal and Collisionless Electron Dynamics

    SciTech Connect

    Igor D. Kaganovich; Oleg Polomarov

    2003-05-19

    In low-pressure discharges, when the electron mean free path is larger or comparable with the discharge length, the electron dynamics is essentially non-local. Moreover, the electron energy distribution function (EEDF) deviates considerably from a Maxwellian. Therefore, an accurate kinetic description of the low-pressure discharges requires knowledge of the non-local conductivity operator and calculation of the non-Maxwellian EEDF. The previous treatments made use of simplifying assumptions: a uniform density profile and a Maxwellian EEDF. In the present study a self-consistent system of equations for the kinetic description of nonlocal, non-uniform, nearly collisionless plasmas of low-pressure discharges is derived. It consists of the nonlocal conductivity operator and the averaged kinetic equation for calculation of the non-Maxwellian EEDF. The importance of accounting for the non-uniform plasma density profile on both the current density profile and the EEDF is demonstrated.

  1. Exact result vs. dynamic renormalization group analysis for the non-local Kardar-Parisi-Zhang equation

    NASA Astrophysics Data System (ADS)

    Katzav, Eytan

    2002-06-01

    In this paper I discuss a generalization of the well-known Kardar-Parisi-Zhang (KPZ) equation that includes long-range interactions. This Non-local Kardar-Parisi-Zhang (NKPZ) equation has been suggested in the past to describe physical phenomena such as burning paper or deposition of colloids. I show that the steady state strong coupling solution for a subfamily of the NKPZ models can be solved exactly in one dimension, using the Fokker-Planck form of the equation, and yields a Gaussian distribution. This exact result does not agree with a previous result obtained by dynamic renormalization group (DRG) analysis. The reasons for this disagreement are not yet clear.

  2. Traveling waves in the nonlocal KPP-Fisher equation: Different roles of the right and the left interactions

    NASA Astrophysics Data System (ADS)

    Hasik, Karel; Kopfová, Jana; Nábělková, Petra; Trofimchuk, Sergei

    2016-04-01

    We consider the nonlocal KPP-Fisher equation ut (t , x) =uxx (t , x) + u (t , x) (1 - (K * u) (t , x)) which describes the evolution of population density u (t , x) with respect to time t and location x. The non-locality is expressed in terms of the convolution of u (t , ṡ) with kernel K (ṡ) ≥ 0, ∫R K (s) ds = 1. The restrictions K (s), s ≥ 0, and K (s), s ≤ 0, are responsible for interactions of an individual with his left and right neighbors, respectively. We show that these two parts of K play quite different roles as for the existence and uniqueness of traveling fronts to the KPP-Fisher equation. In particular, if the left interaction is dominant, the uniqueness of fronts can be proved, while the dominance of the right interaction can induce the co-existence of monotone and oscillating fronts. We also present a short proof of the existence of traveling waves without assuming various technical restrictions usually imposed on K.

  3. Rate-Independent Dynamics and Kramers-Type Phase Transitions in Nonlocal Fokker-Planck Equations with Dynamical Control

    NASA Astrophysics Data System (ADS)

    Herrmann, Michael; Niethammer, Barbara; Velázquez, Juan J. L.

    2014-08-01

    The hysteretic behavior of many-particle systems with non-convex free energy can be modeled by nonlocal Fokker-Planck equations that involve two small parameters and are driven by a time-dependent constraint. In this paper we consider the fast reaction regime related to Kramers-type phase transitions and show that the dynamics in the small-parameter limit can be described by a rate-independent evolution equation with hysteresis. For the proof we first derive mass-dissipation estimates by means of Muckenhoupt constants, formulate conditional stability estimates, and characterize the mass flux between the different phases in terms of moment estimates that encode large deviation results. Afterwards we combine all these partial results and establish the dynamical stability of localized peaks as well as sufficiently strong compactness results for the basic macroscopic quantities.

  4. (2+1)-dimensional dissipation nonlinear Schrödinger equation for envelope Rossby solitary waves and chirp effect

    NASA Astrophysics Data System (ADS)

    Jin-Yuan, Li; Nian-Qiao, Fang; Ji, Zhang; Yu-Long, Xue; Xue-Mu, Wang; Xiao-Bo, Yuan

    2016-04-01

    In the past few decades, the (1+1)-dimensional nonlinear Schrödinger (NLS) equation had been derived for envelope Rossby solitary waves in a line by employing the perturbation expansion method. But, with the development of theory, we note that the (1+1)-dimensional model cannot reflect the evolution of envelope Rossby solitary waves in a plane. In this paper, by constructing a new (2+1)-dimensional multiscale transform, we derive the (2+1)-dimensional dissipation nonlinear Schrödinger equation (DNLS) to describe envelope Rossby solitary waves under the influence of dissipation which propagate in a plane. Especially, the previous researches about envelope Rossby solitary waves were established in the zonal area and could not be applied directly to the spherical earth, while we adopt the plane polar coordinate and overcome the problem. By theoretical analyses, the conservation laws of (2+1)-dimensional envelope Rossby solitary waves as well as their variation under the influence of dissipation are studied. Finally, the one-soliton and two-soliton solutions of the (2+1)-dimensional NLS equation are obtained with the Hirota method. Based on these solutions, by virtue of the chirp concept from fiber soliton communication, the chirp effect of envelope Rossby solitary waves is discussed, and the related impact factors of the chirp effect are given. Project supported by the National Natural Science Foundation of China (Grant No. 41406018).

  5. Spreading speeds and traveling waves for a nonlocal dispersal equation with convolution-type crossing-monostable nonlinearity

    NASA Astrophysics Data System (ADS)

    Zhang, Guo-Bao; Ma, Ruyun

    2014-10-01

    This paper is concerned with the traveling wave solutions and the spreading speeds for a nonlocal dispersal equation with convolution-type crossing-monostable nonlinearity, which is motivated by an age-structured population model with time delay. We first prove the existence of traveling wave solution with critical wave speed c = c*. By introducing two auxiliary monotone birth functions and using a fluctuation method, we further show that the number c = c* is also the spreading speed of the corresponding initial value problem with compact support. Then, the nonexistence of traveling wave solutions for c < c* is established. Finally, by means of the (technical) weighted energy method, we prove that the traveling wave with large speed is exponentially stable, when the initial perturbation around the wave is relatively small in a weighted norm.

  6. Stability of Planar Fronts for a Non-Local Phase Kinetics Equation with a Conservation Law in D ≤ 3

    NASA Astrophysics Data System (ADS)

    Carlen, Eric A.; Orlandi, Enza

    2012-05-01

    We consider, in a D-dimensional cylinder, a non-local evolution equation that describes the evolution of the local magnetization in a continuum limit of an Ising spin system with Kawasaki dynamics and Kac potentials. We consider sub-critical temperatures, for which there are two local spatially homogeneous equilibria, and show a local nonlinear stability result for the minimum free energy profiles for the magnetization at the interface between regions of these two different local equilibrium; i.e. the planar fronts: We show that an initial perturbation of a front that is sufficiently small in L2 norm, and sufficiently localized yields a solution that relaxes to another front, selected by a conservation law, in the L1 norm at an algebraic rate that we explicitly estimate. We also obtain rates for the relaxation in the L2 norm and the rate of decrease of the excess free energy.

  7. Seismology of the solar envelope - Towards the calibration of the equation of state

    NASA Astrophysics Data System (ADS)

    Vorontsov, S. V.; Baturin, V. A.; Pamiatnykh, A. A.

    1992-07-01

    The solar p-mode frequencies represent a unique source of observational information about the physical properties of the solar interior, including the equation of state (EPS). The influence of possible uncertainties in the EOS on the frequencies is small, and mixed with a variety of possible uncertainties in solar structure and physics of the oscillations. This paper describes a technique aimed at separating the effects of the EOS in the information contained in the intermediate-degree data by extracting some functions, or 'tracers', sensitive to the EOS, and insensitive, as far as possible, to the irrelevant effects. The possibilities of the technology are examined by testing a variety of solar envelope models computed with four versions of EOS, in increasing degree of sophistication: (1) EOS of partially ionized ideal gas; (2) EOS with Debye-Hueckel electrostatic corrections; (3) EOS with short-range corrections to the Debye-Hueckel term, and (4) the most recent (Mihalas, et al.) MHD equation of state. By comparing the models with observational data, the effects of the electrostatic corrections are discussed, and first tentative conclusions on two more elaborate versions of the EOS are drawn.

  8. Solution of Poisson's Equation with Global, Local and Nonlocal Boundary Conditions

    ERIC Educational Resources Information Center

    Aliev, Nihan; Jahanshahi, Mohammad

    2002-01-01

    Boundary value problems (BVPs) for partial differential equations are common in mathematical physics. The differential equation is often considered in simple and symmetric regions, such as a circle, cube, cylinder, etc., with global and separable boundary conditions. In this paper and other works of the authors, a general method is used for the…

  9. Modeling tracer transport in randomly heterogeneous porous media by nonlocal moment equations: Anomalous transport

    NASA Astrophysics Data System (ADS)

    Morales-Casique, E.; Lezama-Campos, J. L.; Guadagnini, A.; Neuman, S. P.

    2013-05-01

    Modeling tracer transport in geologic porous media suffers from the corrupt characterization of the spatial distribution of hydrogeologic properties of the system and the incomplete knowledge of processes governing transport at multiple scales. Representations of transport dynamics based on a Fickian model of the kind considered in the advection-dispersion equation (ADE) fail to capture (a) the temporal variation associated with the rate of spreading of a tracer, and (b) the distribution of early and late arrival times which are often observed in field and/or laboratory scenarios and are considered as the signature of anomalous transport. Elsewhere we have presented exact stochastic moment equations to model tracer transport in randomly heterogeneous aquifers. We have also developed a closure scheme which enables one to provide numerical solutions of such moment equations at different orders of approximations. The resulting (ensemble) average and variance of concentration fields were found to display a good agreement against Monte Carlo - based simulation results for mildly heterogeneous (or well-conditioned strongly heterogeneous) media. Here we explore the ability of the moment equations approach to describe the distribution of early arrival times and late time tailing effects which can be observed in Monte-Carlo based breakthrough curves (BTCs) of the (ensemble) mean concentration. We show that BTCs of mean resident concentration calculated at a fixed space location through higher-order approximations of moment equations display long tailing features of the kind which is typically associated with anomalous transport behavior and are not represented by an ADE model with constant dispersive parameter, such as the zero-order approximation.

  10. Multiple beam envelope equations for electron injectors using a bunch segmentation model

    NASA Astrophysics Data System (ADS)

    Mizuno, A.; Dewa, H.; Taniuchi, T.; Tomizawa, H.; Hanaki, H.; Hotta, E.

    2012-06-01

    A new semianalytical method of investigating the beam dynamics for electron injectors was developed. In this method, a short bunched electron beam is assumed to be an ensemble of several segmentation pieces in both the longitudinal and the transverse directions. The trajectory of each electron in the segmentation pieces is solved by the beam envelope equations while taking into account the space charge fields produced by all the pieces, the electromagnetic fields of an rf cavity, and the image charge fields at a cathode surface. The shape of the entire bunch is consequently calculated, and thus the emittances can be obtained from weighted mean values of the solutions for the obtained electron trajectories. The advantage of this method is its unique assumption for the beam parameters. We assume that each segmentation slice is not warped in the calculations. Although if the beam energy is low and the charge density is large, this condition is not satisfied, in practice, this condition is usually satisfied. We have performed beam dynamics calculations to obtain traces in free space and in the BNL-type rf gun cavity by comparing the analytical solutions with those obtained by simulation. In most cases, the emittances obtained by the simulation become closer to those obtained analytically with increasing the number of particles used in the simulation. Therefore, the analytically obtained emittances are expected to coincide with converged values obtained by the simulation. The applicable range of the analytical method for the BNL-type rf gun cavity is under 0.5 nC per bunch. This range is often used in recently built x-ray free electron laser facilities.

  11. Dynamics of higher-order rational solitons for the nonlocal nonlinear Schrödinger equation with the self-induced parity-time-symmetric potential.

    PubMed

    Wen, Xiao-Yong; Yan, Zhenya; Yang, Yunqing

    2016-06-01

    The integrable nonlocal nonlinear Schrödinger equation with the self-induced parity-time-symmetric potential [M. J. Ablowitz and Z. H. Musslimani, Phys. Rev. Lett. 110, 064105 (2013)] is investigated, which is an integrable extension of the standard nonlinear Schrödinger equation. Its novel higher-order rational solitons are found using the nonlocal version of the generalized perturbation (1,N-1)-fold Darboux transformation. These rational solitons illustrate abundant wave structures for the distinct choices of parameters (e.g., the strong and weak interactions of bright and dark rational solitons). Moreover, we also explore the dynamical behaviors of these higher-order rational solitons with some small noises on the basis of numerical simulations. PMID:27368788

  12. A generalized nonlocal vector calculus

    NASA Astrophysics Data System (ADS)

    Alali, Bacim; Liu, Kuo; Gunzburger, Max

    2015-10-01

    A nonlocal vector calculus was introduced in Du et al. (Math Model Meth Appl Sci 23:493-540, 2013) that has proved useful for the analysis of the peridynamics model of nonlocal mechanics and nonlocal diffusion models. A formulation is developed that provides a more general setting for the nonlocal vector calculus that is independent of particular nonlocal models. It is shown that general nonlocal calculus operators are integral operators with specific integral kernels. General nonlocal calculus properties are developed, including nonlocal integration by parts formula and Green's identities. The nonlocal vector calculus introduced in Du et al. (Math Model Meth Appl Sci 23:493-540, 2013) is shown to be recoverable from the general formulation as a special example. This special nonlocal vector calculus is used to reformulate the peridynamics equation of motion in terms of the nonlocal gradient operator and its adjoint. A new example of nonlocal vector calculus operators is introduced, which shows the potential use of the general formulation for general nonlocal models.

  13. Generalized Kapchinskij-Vladimirskij Distribution and Envelope Equation for High-intensity Beams in a Coupled Transverse Focusing Lattice

    SciTech Connect

    Hong Qin, Moses Chung, and Ronald C. Davidson

    2009-11-20

    In an uncoupled lattice, the Kapchinskij-Vladimirskij (KV) distribution function first analyzed in 1959 is the only known exact solution of the nonlinear Vlasov-Maxwell equations for high- intensity beams including self-fields in a self-consistent manner. The KV solution is generalized here to high-intensity beams in a coupled transverse lattice using the recently developed generalized Courant-Snyder invariant for coupled transverse dynamics. This solution projects to a rotating, pulsating elliptical beam in transverse configuration space, determined by the generalized matrix envelope equation.

  14. Symmetries and exact solutions of a class of nonlocal nonlinear Schrödinger equations with self-induced parity-time-symmetric potential

    NASA Astrophysics Data System (ADS)

    Sinha, Debdeep; Ghosh, Pijush K.

    2015-04-01

    A class of nonlocal nonlinear Schrödinger equations (NLSEs) is considered in an external potential with a space-time modulated coefficient of the nonlinear interaction term as well as confining and/or loss-gain terms. This is a generalization of a recently introduced integrable nonlocal NLSE with self-induced potential that is parity-time-symmetric in the corresponding stationary problem. Exact soliton solutions are obtained for the inhomogeneous and/or nonautonomous nonlocal NLSE by using similarity transformation, and the method is illustrated with a few examples. It is found that only those transformations are allowed for which the transformed spatial coordinate is odd under the parity transformation of the original one. It is shown that the nonlocal NLSE without the external potential and a (d +1 )-dimensional generalization of it admits all the symmetries of the (d +1 )-dimensional Schrödinger group. The conserved Noether charges associated with the time translation, dilatation, and special conformal transformation are shown to be real-valued in spite of being non-Hermitian. Finally, the dynamics of different moments are studied with an exact description of the time evolution of the "pseudowidth" of the wave packet for the special case in which the system admits a O (2 ,1 ) conformal symmetry.

  15. Symmetries and exact solutions of a class of nonlocal nonlinear Schrödinger equations with self-induced parity-time-symmetric potential.

    PubMed

    Sinha, Debdeep; Ghosh, Pijush K

    2015-04-01

    A class of nonlocal nonlinear Schrödinger equations (NLSEs) is considered in an external potential with a space-time modulated coefficient of the nonlinear interaction term as well as confining and/or loss-gain terms. This is a generalization of a recently introduced integrable nonlocal NLSE with self-induced potential that is parity-time-symmetric in the corresponding stationary problem. Exact soliton solutions are obtained for the inhomogeneous and/or nonautonomous nonlocal NLSE by using similarity transformation, and the method is illustrated with a few examples. It is found that only those transformations are allowed for which the transformed spatial coordinate is odd under the parity transformation of the original one. It is shown that the nonlocal NLSE without the external potential and a (d+1)-dimensional generalization of it admits all the symmetries of the (d+1)-dimensional Schrödinger group. The conserved Noether charges associated with the time translation, dilatation, and special conformal transformation are shown to be real-valued in spite of being non-Hermitian. Finally, the dynamics of different moments are studied with an exact description of the time evolution of the "pseudowidth" of the wave packet for the special case in which the system admits a O(2,1) conformal symmetry. PMID:25974563

  16. Nonlocal gravity: Conformally flat spacetimes

    NASA Astrophysics Data System (ADS)

    Bini, Donato; Mashhoon, Bahram

    2016-04-01

    The field equations of the recent nonlocal generalization of Einstein’s theory of gravitation are presented in a form that is reminiscent of general relativity. The implications of the nonlocal field equations are studied in the case of conformally flat spacetimes. Even in this simple case, the field equations are intractable. Therefore, to gain insight into the nature of these equations, we investigate the structure of nonlocal gravity (NLG) in 2D spacetimes. While any smooth 2D spacetime is conformally flat and satisfies Einstein’s field equations, only a subset containing either a Killing vector or a homothetic Killing vector can satisfy the field equations of NLG.

  17. Stochastic averaging of energy envelope of Preisach hysteretic systems

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Ying, Z. G.; Zhu, W. Q.

    2009-04-01

    A new stochastic averaging technique for analyzing the response of a single-degree-of-freedom Preisach hysteretic system with nonlocal memory under stationary Gaussian stochastic excitation is proposed. An equivalent nonhysteretic nonlinear system with amplitude-envelope-dependent damping and stiffness is firstly obtained from the given system by using the generalized harmonic balance technique. The relationship between the amplitude envelope and the energy envelope is then established, and the equivalent damping and stiffness coefficients are expressed as functions of the energy envelope. The available range of the yielding force of the system is extended and also the strong nonlinear stiffness of the system is incorporated so as to improve the response prediction. Finally, an averaged Itô stochastic differential equation for the energy envelope of the system as one-dimensional diffusion process is derived by using the stochastic averaging method of energy envelope, and the Fokker-Planck-Kolmogorov equation associated with the averaged Itô equation is solved to obtain stationary probability densities of the energy envelope and amplitude envelope. The approximate solutions are validated by using the Monte Carlo simulation.

  18. Nonlocality Without Nonlocality

    NASA Astrophysics Data System (ADS)

    Weinstein, Steven

    2009-08-01

    Bell’s theorem is purported to demonstrate the impossibility of a local “hidden variable” theory underpinning quantum mechanics. It relies on the well-known assumption of ‘locality’, and also on a little-examined assumption called ‘statistical independence’ ( SI). Violations of this assumption have variously been thought to suggest “backward causation”, a “conspiracy” on the part of nature, or the denial of “free will”. It will be shown here that these are spurious worries, and that denial of SI simply implies nonlocal correlation between spacelike degrees of freedom. Lorentz-invariant theories in which SI does not hold are easily constructed: two are exhibited here. It is conjectured, on this basis, that quantum-mechanical phenomena may be modeled by a local theory after all.

  19. Single envelope equation modeling of multi-octave comb arrays in microresonators with quadratic and cubic nonlinearities

    NASA Astrophysics Data System (ADS)

    Hansson, Tobias; Leo, François; Erkintalo, Miro; Anthony, Jessienta; Coen, Stéphane; Ricciardi, Iolanda; De Rosa, Maurizio; Wabnitz, Stefan

    2016-06-01

    We numerically study, by means of the single envelope equation, the generation of optical frequency combs ranging from the visible to the mid-infrared spectral regions in resonators with quadratic and cubic nonlinearities. Phase-matched quadratic wave-mixing processes among the comb lines can be activated by low-power continuous wave pumping in the near infrared of a radially poled lithium niobate whispering gallery resonator (WGR). We examine both separate and co-existing intra-cavity doubly resonant second-harmonic generation and parametric oscillation processes, and find that modulation instabilities may lead to the formation of coupled comb arrays extending over multiple octaves. In the temporal domain, the frequency combs may correspond to pulse trains, or isolated pulses.

  20. Nonlocal and quasilocal field theories

    NASA Astrophysics Data System (ADS)

    Tomboulis, E. T.

    2015-12-01

    We investigate nonlocal field theories, a subject that has attracted some renewed interest in connection with nonlocal gravity models. We study, in particular, scalar theories of interacting delocalized fields, the delocalization being specified by nonlocal integral kernels. We distinguish between strictly nonlocal and quasilocal (compact support) kernels and impose conditions on them to insure UV finiteness and unitarity of amplitudes. We study the classical initial value problem for the partial integro-differential equations of motion in detail. We give rigorous proofs of the existence but accompanying loss of uniqueness of solutions due to the presence of future, as well as past, "delays," a manifestation of acausality. In the quantum theory we derive a generalization of the Bogoliubov causality condition equation for amplitudes, which explicitly exhibits the corrections due to nonlocality. One finds that, remarkably, for quasilocal kernels all acausal effects are confined within the compact support regions. We briefly discuss the extension to other types of fields and prospects of such theories.

  1. Deriving k·p parameters from full-Brillouin-zone descriptions: A finite-element envelope function model for quantum-confined wurtzite nanostructures

    SciTech Connect

    Zhou, Xiangyu; Ghione, Giovanni; Bertazzi, Francesco Goano, Michele; Bellotti, Enrico

    2014-07-21

    We present a multiband envelope-function model for wurtzite nanostructures based on a rigorous numerical procedure to determine operator ordering and band parameters from nonlocal empirical pseudopotential calculations. The proposed approach, implemented within a finite-element scheme, leads to well-posed, numerically stable envelope equations that accurately reproduce full-Brillouin-zone subband dispersions of quantum systems. Although demonstrated here for III-nitride nonlocal empirical pseudopotentials, the model provides a general theoretical framework applicable to ab initio electronic structures of wurtzite semiconductors.

  2. Unstable nonlocal interface dynamics.

    PubMed

    Nicoli, Matteo; Cuerno, Rodolfo; Castro, Mario

    2009-06-26

    Nonlocal effects occur in many nonequilibrium interfaces, due to diverse physical mechanisms like diffusive, ballistic, or anomalous transport, with examples from flame fronts to thin films. While dimensional analysis describes stable nonlocal interfaces, we show the morphologically unstable condition to be nontrivial. This is the case for a family of stochastic equations of experimental relevance, paradigmatically including the Michelson-Sivashinsky system. For a whole parameter range, the asymptotic dynamics is scale invariant with dimension-independent exponents reflecting a hidden Galilean symmetry. The usual Kardar-Parisi-Zhang nonlinearity, albeit irrelevant in that parameter range, plays a key role in this behavior. PMID:19659099

  3. Turbulence transport with nonlocal interactions

    SciTech Connect

    Linn, R.R.; Clark, T.T.; Harlow, F.H.; Turner, L.

    1998-03-01

    This preliminary report describes a variety of issues in turbulence transport analysis with particular emphasis on closure procedures that are nonlocal in wave-number and/or physical space. Anomalous behavior of the transport equations for large scale parts of the turbulence spectrum are resolved by including the physical space nonlocal interactions. Direct and reverse cascade processes in wave-number space are given a much richer potential for realistic description by the nonlocal formulations. The discussion also describes issues, many still not resolved, regarding new classes of self-similar form functions.

  4. Frustrated Brownian Motion of Nonlocal Solitary Waves

    SciTech Connect

    Folli, V.; Conti, C.

    2010-05-14

    We investigate the evolution of solitary waves in a nonlocal medium in the presence of disorder. By using a perturbational approach, we show that an increasing degree of nonlocality may largely hamper the Brownian motion of self-trapped wave packets. The result is valid for any kind of nonlocality and in the presence of nonparaxial effects. Analytical predictions are compared with numerical simulations based on stochastic partial differential equations.

  5. Hybrid nonlocality distillation

    NASA Astrophysics Data System (ADS)

    Wu, Keng-Shuo; Hsu, Li-Yi

    2013-08-01

    In this Letter, we introduce the notion of hybrid nonlocality distillation, in which different nonlocal boxes are exploited for nonlocality distillation. Here, we quantify the nonlocality using the violation degree of either the Clauser-Horne-Shimony-Holt inequality or the I3322 inequality. Our study shows that hybrid nonlocality distillation can outperform nonlocality distillation using copies of single nonlocal boxes. In particular, more nonlocality of undistillable boxes can be activated with the assistance of distillable boxes. Equivalently, distillable boxes can achieve more nonlocality with the assistance of undistillable boxes.

  6. Algebraic Rate of Decay for the Excess Free Energy and Stability of Fronts for a Nonlocal Phase Kinetics Equation with a Conservation Law. I

    NASA Astrophysics Data System (ADS)

    Carlen, E. A.; Carvalho, M. C.; Orlandi, E.

    1999-06-01

    This is the first of two papers devoted to the study of a nonlocal evolution equation that describes the evolution of the local magnetization in a continuum limit of an Ising spin system with Kawasaki dynamics and Kac potentials. We consider subcritical temperatures, for which there are two local equilibria, and begin the proof of a local nonlinear stability result for the minimum free energy profiles for the magnetization at the interface between regions of these two different local equilibria; i.e., the fronts. We shall show in the second paper that an initial perturbation v 0 of a front that is sufficiently small in L 2 norm, and sufficiently localized that ∫ x 2 v 0( x)2 dx<∞, yields a solution that relaxes to another front, selected by a conservation law, in the L 1 norm at an algebraic rate that we explicitly estimate. There we also obtain rates for the relaxation in the L 2 norm and the rate of decrease of the excess free energy. Here we prove a number of estimates essential for this result. Moreover, the estimates proved here suffice to establish the main result in an important special case.

  7. Emission lineshapes of the B850 band of light-harvesting 2 (LH2) complex in purple bacteria: A second order time-nonlocal quantum master equation approach

    NASA Astrophysics Data System (ADS)

    Kumar, Praveen; Jang, Seogjoo

    2013-04-01

    The emission lineshape of the B850 band in the light harvesting complex 2 of purple bacteria is calculated by extending the approach of 2nd order time-nonlocal quantum master equation [S. Jang and R. J. Silbey, J. Chem. Phys. 118, 9312 (2003), 10.1063/1.1569239]. The initial condition for the emission process corresponds to the stationary excited state density where exciton states are entangled with the bath modes in equilibrium. This exciton-bath coupling, which is not diagonal in either site excitation or exciton basis, results in a new inhomogeneous term that is absent in the expression for the absorption lineshape. Careful treatment of all the 2nd order terms are made, and explicit expressions are derived for both full 2nd order lineshape expression and the one based on secular approximation that neglects off-diagonal components in the exciton basis. Numerical results are presented for a few representative cases of disorder and temperature. Comparison of emission line shape with the absorption line shape is also made. It is shown that the inhomogeneous term coming from the entanglement of the system and bath degrees of freedom makes significant contributions to the lineshape. It is also found that the perturbative nature of the theory can result in negative portion of lineshape in some situations, which can be removed significantly by inclusion of the inhomogeneous term and completely by using the secular approximation. Comparison of the emission and absorption lineshapes at different temperatures demonstrates the role of thermal population of different exciton states and exciton-phonon couplings.

  8. Origin of Dynamical Quantum Non-locality

    NASA Astrophysics Data System (ADS)

    Pachon, Cesar E.; Pachon, Leonardo A.

    2014-03-01

    Non-locality is one of the hallmarks of quantum mechanics and is responsible for paradigmatic features such as entanglement and the Aharonov-Bohm effect. Non-locality comes in two ``flavours'': a kinematic non-locality- arising from the structure of the Hilbert space- and a dynamical non-locality- arising from the quantum equations of motion-. Kinematic non-locality is unable to induce any change in the probability distributions, so that the ``action-at-a-distance'' cannot manifest. Conversely, dynamical non-locality does create explicit changes in probability, though in a ``causality-preserving'' manner. The origin of non-locality of quantum measurements and its relations to the fundamental postulates of quantum mechanics, such as the uncertainty principle, have been only recently elucidated. Here we trace the origin of dynamical non-locality to the superposition principle. This relation allows us to establish and identify how the uncertainty and the superposition principles determine the non-local character of the outcome of a quantum measurement. Being based on group theoretical and path integral formulations, our formulation admits immediate generalizations and extensions to to, e.g., quantum field theory. This work was supported by the Departamento Administrativo de Ciencia, Tecnologia e Innovacion -COLCIENCIAS- of Colombia under the grant number 111556934912.

  9. Quantum nonlocality does not exist.

    PubMed

    Tipler, Frank J

    2014-08-01

    Quantum nonlocality is shown to be an artifact of the Copenhagen interpretation, in which each observed quantity has exactly one value at any instant. In reality, all physical systems obey quantum mechanics, which obeys no such rule. Locality is restored if observed and observer are both assumed to obey quantum mechanics, as in the many-worlds interpretation (MWI). Using the MWI, I show that the quantum side of Bell's inequality, generally believed nonlocal, is really due to a series of three measurements (not two as in the standard, oversimplified analysis), all three of which have only local effects. Thus, experiments confirming "nonlocality" are actually confirming the MWI. The mistaken interpretation of nonlocality experiments depends crucially on a question-begging version of the Born interpretation, which makes sense only in "collapse" versions of quantum theory, about the meaning of the modulus of the wave function, so I use the interpretation based on the MWI, namely that the wave function is a world density amplitude, not a probability amplitude. This view allows the Born interpretation to be derived directly from the Schrödinger equation, by applying the Schrödinger equation to both the observed and the observer. PMID:25015084

  10. Temporal Non-locality

    NASA Astrophysics Data System (ADS)

    Filk, Thomas

    2013-04-01

    In this article I investigate several possibilities to define the concept of "temporal non-locality" within the standard framework of quantum theory. In particular, I analyze the notions of "temporally non-local states", "temporally non-local events" and "temporally non-local observables". The idea of temporally non-local events is already inherent in the standard formalism of quantum mechanics, and Basil Hiley recently defined an operator in order to measure the degree of such a temporal non-locality. The concept of temporally non-local states enters as soon as "clock-representing states" are introduced in the context of special and general relativity. It is discussed in which way temporally non-local measurements may find an interesting application for experiments which test temporal versions of Bell inequalities.

  11. Quantum ring solitons and nonlocal effects in plasma wake field excitations

    SciTech Connect

    Fedele, R.; Tanjia, F.; De Nicola, S.; Jovanovic, D.; Shukla, P. K.

    2012-10-15

    A theoretical investigation of the quantum transverse beam motion for a cold relativistic charged particle beam travelling in a cold, collisionless, strongly magnetized plasma is carried out. This is done by taking into account both the individual quantum nature of the beam particles (single-particle uncertainty relations and spin) and the self consistent interaction generated by the plasma wake field excitation. By adopting a fluid model of a strongly magnetized plasma, the analysis is carried out in the overdense regime (dilute beams) and in the long beam limit. It is shown that the quantum description of the collective transverse beam dynamics is provided by a pair of coupled nonlinear governing equations. It comprises a Poisson-like equation for the plasma wake potential (driven by the beam density) and a 2D spinorial Schroedinger equation for the wave function, whose squared modulus is proportional to the beam density, that is obtained in the Hartree's mean field approximation, after disregarding the exchange interactions. The analysis of this pair of equations, which in general exhibits a strong nonlocal character, is carried out analytically as well as numerically in both the linear and the nonlinear regimes, showing the existence of the quantum beam vortices in the form of Laguerre-Gauss modes and ring envelope solitons, respectively. In particular, when the relation between the plasma wake field response and the beam probability density is strictly local, the pair of the governing equations is reduced to the 2D Gross-Pitaevskii equation that allows one to establish the conditions for the self focusing and collapse. These conditions include the quantum nature of the beam particles. Finally, when the relation between the plasma wake field response and the beam probability density is moderately nonlocal, the above pair of equations permits to follow the spatio-temporal evolution of a quantum ring envelope soliton. Such a structure exhibits small or violent

  12. Nonsmooth feedback controls of nonlocal dispersal models

    NASA Astrophysics Data System (ADS)

    Malaguti, Luisa; Rubbioni, Paola

    2016-03-01

    The paper deals with a nonlocal diffusion equation which is a model for biological invasion and disease spread. A nonsmooth feedback control term is included and the existence of controlled dynamics is proved, satisfying different kinds of nonlocal condition. Jump discontinuities appear in the process. The existence of optimal control strategies is also shown, under suitably regular control functionals. The investigation makes use of techniques of multivalued analysis and is based on the degree theory for condensing operators in Hilbert spaces.

  13. The equation of state for stellar envelopes. IV - Thermodynamic quantities and selected ionization fractions for six elemental mixes

    NASA Technical Reports Server (NTRS)

    Mihalas, Dimitri; Hummer, D. G.; Mihalas, Barbara Weibel; Daeppen, Werner

    1990-01-01

    The free-energy minimization technique in the form developed in the preceding papers in this series is employed to evaluate thermodynamic quantities and ionization fractions on a fine temperature and density grid for six astrophysical mixtures of 15 elements. The mixtures range from that appropriate to super-metal-rich stars, through solar abundance, to that for extreme Population II objects. In this paper, the results for solar abundances are summarized in a form that is illustrative and which facilitates comparison with the results from other equation of state calculations.

  14. Nonlocal heat transport in a stochastic magnetic field

    SciTech Connect

    Rax, J.M.; White, R.B.

    1991-12-01

    Heat transport in a stochastic magnetic field configuration is shown to be nonlocal. Collisional transport processes, in such a disordered media, cannot always be reduced to a standard diffusion process, and the concept of a diffusion coefficient is meaningless for a wide range of typical tokamak parameters. In the nonlocal regime the relaxation of a gradient is described by an integral equation, involving a nonlocal propagator. This propagator is calculated, and the relation to previous results is elucidated. 15 refs.

  15. Effects of nonlocality on transfer reactions

    NASA Astrophysics Data System (ADS)

    Titus, Luke

    Nuclear reactions play a key role in the study of nuclei away from stability. Single-nucleon transfer reactions involving deuterons provide an exceptional tool to study the single-particle structure of nuclei. Theoretically, these reactions are attractive as they can be cast into a three-body problem composed of a neutron, proton, and the target nucleus. Optical potentials are a common ingredient in reactions studies. Traditionally, nucleon-nucleus optical potentials are made local for convenience. The effects of nonlocal potentials have historically been included approximately by applying a correction factor to the solution of the corresponding equation for the local equivalent interaction. This is usually referred to as the Perey correction factor. In this thesis, we have systematically investigated the effects of nonlocality on (p,d) and (d,p) transfer reactions, and the validity of the Perey correction factor. We implemented a method to solve the single channel nonlocal equation for both bound and scattering states. We also developed an improved formalism for nonlocal interactions that includes deuteron breakup in transfer reactions. This new formalism, the nonlocal adiabatic distorted wave approximation, was used to study the effects of including nonlocality consistently in ( d,p) transfer reactions. For the (p,d) transfer reactions, we solved the nonlocal scattering and bound state equations using the Perey-Buck type interaction, and compared to local equivalent calculations. Using the distorted wave Born approximation we construct the T-matrix for (p,d) transfer on 17O, 41Ca, 49Ca, 127 Sn, 133Sn, and 209Pb at 20 and 50 MeV. Additionally we studied (p,d) reactions on 40Ca using the the nonlocal dispersive optical model. We have also included nonlocality consistently into the adiabatic distorted wave approximation and have investigated the effects of nonlocality on on (d,p) transfer reactions for deuterons impinged on 16O, 40Ca, 48Ca, 126Sn, 132Sn, 208Pb at 10

  16. Quantum nonlocality does not exist

    PubMed Central

    Tipler, Frank J.

    2014-01-01

    Quantum nonlocality is shown to be an artifact of the Copenhagen interpretation, in which each observed quantity has exactly one value at any instant. In reality, all physical systems obey quantum mechanics, which obeys no such rule. Locality is restored if observed and observer are both assumed to obey quantum mechanics, as in the many-worlds interpretation (MWI). Using the MWI, I show that the quantum side of Bell’s inequality, generally believed nonlocal, is really due to a series of three measurements (not two as in the standard, oversimplified analysis), all three of which have only local effects. Thus, experiments confirming “nonlocality” are actually confirming the MWI. The mistaken interpretation of nonlocality experiments depends crucially on a question-begging version of the Born interpretation, which makes sense only in “collapse” versions of quantum theory, about the meaning of the modulus of the wave function, so I use the interpretation based on the MWI, namely that the wave function is a world density amplitude, not a probability amplitude. This view allows the Born interpretation to be derived directly from the Schrödinger equation, by applying the Schrödinger equation to both the observed and the observer. PMID:25015084

  17. Nonlocal magnetorotational instability

    SciTech Connect

    Mikhailovskii, A. B.; Erokhin, N. N.; Lominadze, J. G.; Galvao, R. M. O.; Churikov, A. P.; Kharshiladze, O. A.; Amador, C. H. S.

    2008-05-15

    An analytical theory of the nonlocal magnetorotational instability (MRI) is developed for the simplest astrophysical plasma model. It is assumed that the rotation frequency profile has a steplike character, so that there are two regions in which it has constant different values, separated by a narrow transition layer. The surface wave approach is employed to investigate the MRI in this configuration. It is shown that the main regularities of the nonlocal MRI are similar to those of the local instability and that driving the nonaxisymmetric MRI is less effective than the axisymmetric one, also for the case of the nonlocal instability. The existence of nonlocal instabilities in nonmagnetized plasma is predicted.

  18. Nonlocal General Relativity

    NASA Astrophysics Data System (ADS)

    Mashhoon, Bahram

    2014-12-01

    A brief account of the present status of the recent nonlocal generalization of Einstein's theory of gravitation is presented. The main physical assumptions that underlie this theory are described. We clarify the physical meaning and significance of Weitzenbock's torsion and emphasize its intimate relationship with the gravitational field, characterized by the Riemannian curvature of spacetime. In this theory, nonlocality can simulate dark matter; in fact, in the Newtonian regime, we recover the phenomenological Tohline-Kuhn approach to modified gravity. To account for the observational data regarding dark matter, nonlocality is associated with a characteristic length scale of order 1 kpc. The confrontation of nonlocal gravity with observation is briefly discussed.

  19. A Comparison of Three Stochastic Approaches for Parameter Estimation and Prediction of Steady-State Groundwater Flow: Nonlocal Moment Equations and Monte Carlo Method Coupled with Ensemble Kalman Filter and Geostatistical Stochastic Inversion.

    NASA Astrophysics Data System (ADS)

    Morales-Casique, E.; Briseño-Ruiz, J. V.; Hernández, A. F.; Herrera, G. S.; Escolero-Fuentes, O.

    2014-12-01

    We present a comparison of three stochastic approaches for estimating log hydraulic conductivity (Y) and predicting steady-state groundwater flow. Two of the approaches are based on the data assimilation technique known as ensemble Kalman filter (EnKF) and differ in the way prior statistical moment estimates (PSME) (required to build the Kalman gain matrix) are obtained. In the first approach, the Monte Carlo method is employed to compute PSME of the variables and parameters; we denote this approach by EnKFMC. In the second approach PSME are computed through the direct solution of approximate nonlocal (integrodifferential) equations that govern the spatial conditional ensemble means (statistical expectations) and covariances of hydraulic head (h) and fluxes; we denote this approach by EnKFME. The third approach consists of geostatistical stochastic inversion of the same nonlocal moment equations; we denote this approach by IME. In addition to testing the EnKFMC and EnKFME methods in the traditional manner that estimate Y over the entire grid, we propose novel corresponding algorithms that estimate Y at a few selected locations and then interpolate over all grid elements via kriging as done in the IME method. We tested these methods to estimate Y and h in steady-state groundwater flow in a synthetic two-dimensional domain with a well pumping at a constant rate, located at the center of the domain. In addition, to evaluate the performance of the estimation methods, we generated four unconditional different realizations that served as "true" fields. The results of our numerical experiments indicate that the three methods were effective in estimating h, reaching at least 80% of predictive coverage, although both EnKF were superior to the IME method. With respect to estimating Y, the three methods reached similar accuracy in terms of the mean absolute value error. Coupling the EnKF methods with kriging to estimate Y reduces to one fourth the CPU time required for data

  20. Anisotropic charged core envelope star

    NASA Astrophysics Data System (ADS)

    Mafa Takisa, P.; Maharaj, S. D.

    2016-08-01

    We study a charged compact object with anisotropic pressures in a core envelope setting. The equation of state is quadratic in the core and linear in the envelope. There is smooth matching between the three regions: the core, envelope and the Reissner-Nordström exterior. We show that the presence of the electric field affects the masses, radii and compactification factors of stellar objects with values which are in agreement with previous studies. We investigate in particular the effect of electric field on the physical features of the pulsar PSR J1614-2230 in the core envelope model. The gravitational potentials and the matter variables are well behaved within the stellar object. We demonstrate that the radius of the core and the envelope can vary by changing the parameters in the speed of sound.

  1. Effectively nonlocal metric-affine gravity

    NASA Astrophysics Data System (ADS)

    Golovnev, Alexey; Koivisto, Tomi; Sandstad, Marit

    2016-03-01

    In metric-affine theories of gravity such as the C-theories, the spacetime connection is associated to a metric that is nontrivially related to the physical metric. In this article, such theories are rewritten in terms of a single metric, and it is shown that they can be recast as effectively nonlocal gravity. With some assumptions, known ghost-free theories with nonsingular and cosmologically interesting properties may be recovered. Relations between different formulations are analyzed at both perturbative and nonperturbative levels, taking carefully into account subtleties with boundary conditions in the presence of integral operators in the action, and equivalences between theories related by nonlocal redefinitions of the fields are verified at the level of equations of motion. This suggests a possible geometrical interpretation of nonlocal gravity as an emergent property of non-Riemannian spacetime structure.

  2. Nonlocal spectroscopy of Andreev bound states

    NASA Astrophysics Data System (ADS)

    Schindele, J.; Baumgartner, A.; Maurand, R.; Weiss, M.; Schönenberger, C.

    2014-01-01

    We experimentally investigate Andreev bound states (ABSs) in a carbon nanotube quantum dot (QD) connected to a superconducting Nb lead (S). A weakly coupled normal metal contact acts as a tunnel probe that measures the energy dispersion of the ABSs. Moreover, we study the response of the ABS to nonlocal transport processes, namely, Cooper pair splitting and elastic co-tunnelling, which are enabled by a second QD fabricated on the same nanotube on the opposite side of S. We find an appreciable nonlocal conductance with a rich structure, including a sign reversal at the ground-state transition from the ABS singlet to a degenerate magnetic doublet. We describe our device by a simple rate equation model that captures the key features of our observations and demonstrates that the sign of the nonlocal conductance is a measure for the charge distribution of the ABS, given by the respective Bogoliubov-de Gennes amplitudes u and v.

  3. Multipartite nonlocality distillation

    SciTech Connect

    Hsu, Li-Yi; Wu, Keng-Shuo

    2010-11-15

    The stronger nonlocality than that allowed in quantum theory can provide an advantage in information processing and computation. Since quantum entanglement is distillable, can nonlocality be distilled in the nonsignalling condition? The answer is positive in the bipartite case. In this article the distillability of the multipartite nonlocality is investigated. We propose a distillation protocol solely exploiting xor operations on output bits. The probability-distribution vectors and matrix are introduced to tackle the correlators. It is shown that only the correlators with extreme values can survive the distillation process. As the main result, the amplified nonlocality cannot maximally violate any Bell-type inequality. Accordingly, a distillability criterion in the postquantum region is proposed.

  4. Making space for nonlocality

    NASA Astrophysics Data System (ADS)

    Millen, James

    2016-04-01

    George Musser's book Spooky Action at a Distance focuses on one of quantum physics' more challenging concepts, nonlocality, and its multitude of implications, particularly its assault on space itself.

  5. Testing Quantum Gravity Induced Nonlocality via Optomechanical Quantum Oscillators.

    PubMed

    Belenchia, Alessio; Benincasa, Dionigi M T; Liberati, Stefano; Marin, Francesco; Marino, Francesco; Ortolan, Antonello

    2016-04-22

    Several quantum gravity scenarios lead to physics below the Planck scale characterized by nonlocal, Lorentz invariant equations of motion. We show that such nonlocal effective field theories lead to a modified Schrödinger evolution in the nonrelativistic limit. In particular, the nonlocal evolution of optomechanical quantum oscillators is characterized by a spontaneous periodic squeezing that cannot be generated by environmental effects. We discuss constraints on the nonlocality obtained by past experiments, and show how future experiments (already under construction) will either see such effects or otherwise cast severe bounds on the nonlocality scale (well beyond the current limits set by the Large Hadron Collider). This paves the way for table top, high precision experiments on massive quantum objects as a promising new avenue for testing some quantum gravity phenomenology. PMID:27152787

  6. Testing Quantum Gravity Induced Nonlocality via Optomechanical Quantum Oscillators

    NASA Astrophysics Data System (ADS)

    Belenchia, Alessio; Benincasa, Dionigi M. T.; Liberati, Stefano; Marin, Francesco; Marino, Francesco; Ortolan, Antonello

    2016-04-01

    Several quantum gravity scenarios lead to physics below the Planck scale characterized by nonlocal, Lorentz invariant equations of motion. We show that such nonlocal effective field theories lead to a modified Schrödinger evolution in the nonrelativistic limit. In particular, the nonlocal evolution of optomechanical quantum oscillators is characterized by a spontaneous periodic squeezing that cannot be generated by environmental effects. We discuss constraints on the nonlocality obtained by past experiments, and show how future experiments (already under construction) will either see such effects or otherwise cast severe bounds on the nonlocality scale (well beyond the current limits set by the Large Hadron Collider). This paves the way for table top, high precision experiments on massive quantum objects as a promising new avenue for testing some quantum gravity phenomenology.

  7. COMMON ENVELOPE: ENTHALPY CONSIDERATION

    SciTech Connect

    Ivanova, N.; Chaichenets, S.

    2011-04-20

    In this Letter, we discuss a modification to the criterion for the common envelope (CE) event to result in envelope dispersion. We emphasize that the current energy criterion for the CE phase is not sufficient for an instability of the CE, nor for an ejection. However, in some cases, stellar envelopes undergo stationary mass outflows, which are likely to occur during the slow spiral-in stage of the CE event. We propose the condition for such outflows, in a manner similar to the currently standard {alpha}{sub CE}{lambda}-prescription but with an addition of P/{rho} term in the energy balance equation, accounting therefore for the enthalpy of the envelope rather than merely the gas internal energy. This produces a significant correction, which might help to dispense with an unphysically high value of energy efficiency parameter during the CE phase, currently required in the binary population synthesis studies to make the production of low-mass X-ray binaries with a black hole companion to match the observations.

  8. Geometric reduction of dynamical nonlocality in nanoscale quantum circuits

    PubMed Central

    Strambini, E.; Makarenko, K. S.; Abulizi, G.; de Jong, M. P.; van der Wiel, W. G.

    2016-01-01

    Nonlocality is a key feature discriminating quantum and classical physics. Quantum-interference phenomena, such as Young’s double slit experiment, are one of the clearest manifestations of nonlocality, recently addressed as dynamical to specify its origin in the quantum equations of motion. It is well known that loss of dynamical nonlocality can occur due to (partial) collapse of the wavefunction due to a measurement, such as which-path detection. However, alternative mechanisms affecting dynamical nonlocality have hardly been considered, although of crucial importance in many schemes for quantum information processing. Here, we present a fundamentally different pathway of losing dynamical nonlocality, demonstrating that the detailed geometry of the detection scheme is crucial to preserve nonlocality. By means of a solid-state quantum-interference experiment we quantify this effect in a diffusive system. We show that interference is not only affected by decoherence, but also by a loss of dynamical nonlocality based on a local reduction of the number of quantum conduction channels of the interferometer. With our measurements and theoretical model we demonstrate that this mechanism is an intrinsic property of quantum dynamics. Understanding the geometrical constraints protecting nonlocality is crucial when designing quantum networks for quantum information processing. PMID:26732751

  9. Geometric reduction of dynamical nonlocality in nanoscale quantum circuits

    NASA Astrophysics Data System (ADS)

    Strambini, E.; Makarenko, K. S.; Abulizi, G.; de Jong, M. P.; van der Wiel, W. G.

    2016-01-01

    Nonlocality is a key feature discriminating quantum and classical physics. Quantum-interference phenomena, such as Young’s double slit experiment, are one of the clearest manifestations of nonlocality, recently addressed as dynamical to specify its origin in the quantum equations of motion. It is well known that loss of dynamical nonlocality can occur due to (partial) collapse of the wavefunction due to a measurement, such as which-path detection. However, alternative mechanisms affecting dynamical nonlocality have hardly been considered, although of crucial importance in many schemes for quantum information processing. Here, we present a fundamentally different pathway of losing dynamical nonlocality, demonstrating that the detailed geometry of the detection scheme is crucial to preserve nonlocality. By means of a solid-state quantum-interference experiment we quantify this effect in a diffusive system. We show that interference is not only affected by decoherence, but also by a loss of dynamical nonlocality based on a local reduction of the number of quantum conduction channels of the interferometer. With our measurements and theoretical model we demonstrate that this mechanism is an intrinsic property of quantum dynamics. Understanding the geometrical constraints protecting nonlocality is crucial when designing quantum networks for quantum information processing.

  10. Linear delta-f simulations of nonlocal electron heat transport

    SciTech Connect

    Brunner, S.; Valeo, E.; Krommes, J.A.

    2000-01-27

    Nonlocal electron heat transport calculations are carried out by making use of some of the techniques developed previously for extending the delta f method to transport time scale simulations. By considering the relaxation of small amplitude temperature perturbations of a homogeneous Maxwellian background, only the linearized Fokker-Planck equation has to be solved, and direct comparisons can be made with the equivalent, nonlocal hydrodynamic approach. A quasineutrality-conserving algorithm is derived for computing the self-consistent electric fields driving the return currents. In the low-collisionality regime, results illustrate the importance of taking account of nonlocality in both space and time.

  11. Quantum networks reveal quantum nonlocality.

    PubMed

    Cavalcanti, Daniel; Almeida, Mafalda L; Scarani, Valerio; Acín, Antonio

    2011-01-01

    The results of local measurements on some composite quantum systems cannot be reproduced classically. This impossibility, known as quantum nonlocality, represents a milestone in the foundations of quantum theory. Quantum nonlocality is also a valuable resource for information-processing tasks, for example, quantum communication, quantum key distribution, quantum state estimation or randomness extraction. Still, deciding whether a quantum state is nonlocal remains a challenging problem. Here, we introduce a novel approach to this question: we study the nonlocal properties of quantum states when distributed and measured in networks. We show, using our framework, how any one-way entanglement distillable state leads to nonlocal correlations and prove that quantum nonlocality is a non-additive resource, which can be activated. There exist states, local at the single-copy level, that become nonlocal when taking several copies of them. Our results imply that the nonlocality of quantum states strongly depends on the measurement context. PMID:21304513

  12. SAFEGUARDS ENVELOPE

    SciTech Connect

    Duc Cao; Richard Metcalf

    2010-07-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details advanced statistical techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z-testing. A brief analysis of the impact of the safeguards optimization on the rest of plant efficiency, criticality concerns, and overall requirements is presented.

  13. A caveat on building nonlocal models of cosmology

    SciTech Connect

    Tsamis, N.C.; Woodard, R.P. E-mail: woodard@phys.ufl.edu

    2014-09-01

    Nonlocal models of cosmology might derive from graviton loop corrections to the effective field equations from the epoch of primordial inflation. Although the Schwinger-Keldysh formalism would automatically produce causal and conserved effective field equations, the models so far proposed have been purely phenomenological. Two techniques have been employed to generate causal and conserved field equations: either varying an invariant nonlocal effective action and then enforcing causality by the ad hoc replacement of any advanced Green's function with its retarded counterpart, or else introducing causal nonlocality into a general ansatz for the field equations and then enforcing conservation. We point out here that the two techniques access very different classes of models, and that neither one of them may represent what would actually arise from fundamental theory.

  14. Kummer solitons in strongly nonlocal nonlinear media

    NASA Astrophysics Data System (ADS)

    Zhong, Wei-Ping; Belić, Milivoj

    2009-01-01

    We solve the three-dimensional (3D) time-dependent strongly nonlocal nonlinear Schrödinger equation (NNSE) in spherical coordinates, with the help of Kummer's functions. We obtain analytical solitary solutions, which we term the Kummer solitons. We compare analytical solutions with the numerical solutions of NNSE. We discuss higher-order Kummer spatial solitons, which can exist in various forms, such as the 3D vortex solitons and the multipole solitons.

  15. Teaching Quantum Nonlocality

    ERIC Educational Resources Information Center

    Hobson, Art

    2012-01-01

    Nonlocality arises from the unified "all or nothing" interactions of a spatially extended field quantum such as a photon or an electron. In the double-slit experiment with light, for example, each photon comes through both slits and arrives at the viewing screen as an extended but unified energy bundle or "field quantum." When the photon interacts…

  16. Effects of nonlocal potentials on (p ,d ) transfer reactions

    NASA Astrophysics Data System (ADS)

    Ross, A.; Titus, L. J.; Nunes, F. M.; Mahzoon, M. H.; Dickhoff, W. H.; Charity, R. J.

    2015-10-01

    Background: Although local phenomenological optical potentials have been standardly used to interpret nuclear reactions, recent studies suggest the effects of nonlocality should not be neglected. Purpose: In this work we investigate the effects of nonlocality in (p ,d ) transfer reactions using nonlocal optical potentials. We compare results obtained with the dispersive optical model to those obtained using the Perey-Buck interaction. Method: We solve the scattering and bound-state equations for the nonlocal version of the dispersive optical model. Then, using the distorted-wave Born approximation, we calculate the transfer cross section for (p ,d ) on 40Ca at Ep=20 , 35, and 50 MeV. Results: The inclusion of nonlocality in the bound state has a larger effect than that in the scattering states. The overall effect on the transfer cross section is very significant. We found an increase due to nonlocality in the transfer cross section of ≈30 - 50 % when using the Perey-Buck interaction and of ≈15 - 50 % when using the dispersive optical potential. Conclusions: Although the details of the nonlocal interaction can change the magnitude of the effects, our study shows that qualitatively the results obtained using the dispersive optical potential and the Perey-Buck interaction are consistent, in both cases the transfer cross sections are significantly increased.

  17. Nonlocal Reformulations of Water and Internal Waves and Asymptotic Reductions

    NASA Astrophysics Data System (ADS)

    Ablowitz, Mark J.

    2009-09-01

    Nonlocal reformulations of the classical equations of water waves and two ideal fluids separated by a free interface, bounded above by either a rigid lid or a free surface, are obtained. The kinematic equations may be written in terms of integral equations with a free parameter. By expressing the pressure, or Bernoulli, equation in terms of the surface/interface variables, a closed system is obtained. An advantage of this formulation, referred to as the nonlocal spectral (NSP) formulation, is that the vertical component is eliminated, thus reducing the dimensionality and fixing the domain in which the equations are posed. The NSP equations and the Dirichlet-Neumann operators associated with the water wave or two-fluid equations can be related to each other and the Dirichlet-Neumann series can be obtained from the NSP equations. Important asymptotic reductions obtained from the two-fluid nonlocal system include the generalizations of the Benney-Luke and Kadomtsev-Petviashvili (KP) equations, referred to as intermediate-long wave (ILW) generalizations. These 2+1 dimensional equations possess lump type solutions. In the water wave problem high-order asymptotic series are obtained for two and three dimensional gravity-capillary solitary waves. In two dimensions, the first term in the asymptotic series is the well-known hyperbolic secant squared solution of the KdV equation; in three dimensions, the first term is the rational lump solution of the KP equation.

  18. A higher-order nonlocal elasticity and strain gradient theory and its applications in wave propagation

    NASA Astrophysics Data System (ADS)

    Lim, C. W.; Zhang, G.; Reddy, J. N.

    2015-05-01

    In recent years there have been many papers that considered the effects of material length scales in the study of mechanics of solids at micro- and/or nano-scales. There are a number of approaches and, among them, one set of papers deals with Eringen's differential nonlocal model and another deals with the strain gradient theories. The modified couple stress theory, which also accounts for a material length scale, is a form of a strain gradient theory. The large body of literature that has come into existence in the last several years has created significant confusion among researchers about the length scales that these various theories contain. The present paper has the objective of establishing the fact that the length scales present in nonlocal elasticity and strain gradient theory describe two entirely different physical characteristics of materials and structures at nanoscale. By using two principle kernel functions, the paper further presents a theory with application examples which relates the classical nonlocal elasticity and strain gradient theory and it results in a higher-order nonlocal strain gradient theory. In this theory, a higher-order nonlocal strain gradient elasticity system which considers higher-order stress gradients and strain gradient nonlocality is proposed. It is based on the nonlocal effects of the strain field and first gradient strain field. This theory intends to generalize the classical nonlocal elasticity theory by introducing a higher-order strain tensor with nonlocality into the stored energy function. The theory is distinctive because the classical nonlocal stress theory does not include nonlocality of higher-order stresses while the common strain gradient theory only considers local higher-order strain gradients without nonlocal effects in a global sense. By establishing the constitutive relation within the thermodynamic framework, the governing equations of equilibrium and all boundary conditions are derived via the variational

  19. Lévy flights and nonlocal quantum dynamics

    NASA Astrophysics Data System (ADS)

    Garbaczewski, Piotr; Stephanovich, Vladimir

    2013-07-01

    We develop a fully fledged theory of quantum dynamical patterns of behavior that are nonlocally induced. To this end we generalize the standard Laplacian-based framework of the Schrödinger picture quantum evolution to that employing nonlocal (pseudodifferential) operators. Special attention is paid to the Salpeter (here, m ⩾ 0) quasirelativistic equation and the evolution of various wave packets, in particular to their radial expansion in 3D. Foldy's synthesis of "covariant particle equations" is extended to encompass free Maxwell theory, which however is devoid of any "particle" content. Links with the photon wave mechanics are explored.

  20. Superlinear nonlocal fractional problems with infinitely many solutions

    NASA Astrophysics Data System (ADS)

    Binlin, Zhang; Molica Bisci, Giovanni; Servadei, Raffaella

    2015-07-01

    In this paper we study the existence of infinitely many weak solutions for equations driven by nonlocal integrodifferential operators with homogeneous Dirichlet boundary conditions. A model for these operators is given by the fractional Laplacian where s ∈ (0, 1) is fixed. We consider different superlinear growth assumptions on the nonlinearity, starting from the well-known Ambrosetti-Rabinowitz condition. In this framework we obtain three different results about the existence of infinitely many weak solutions for the problem under consideration, by using the Fountain Theorem. All these theorems extend some classical results for semilinear Laplacian equations to the nonlocal fractional setting.

  1. A theory of non-local linear drift wave transport

    SciTech Connect

    Moradi, S.; Anderson, J.; Weyssow, B.

    2011-06-15

    Transport events in turbulent tokamak plasmas often exhibit non-local or non-diffusive action at a distance features that so far have eluded a conclusive theoretical description. In this paper a theory of non-local transport is investigated through a Fokker-Planck equation with fractional velocity derivatives. A dispersion relation for density gradient driven linear drift modes is derived including the effects of the fractional velocity derivative in the Fokker-Planck equation. It is found that a small deviation (a few percent) from the Maxwellian distribution function alters the dispersion relation such that the growth rates are substantially increased and thereby may cause enhanced levels of transport.

  2. A radial basis function Galerkin method for inhomogeneous nonlocal diffusion

    DOE PAGESBeta

    Lehoucq, Richard B.; Rowe, Stephen T.

    2016-02-01

    We introduce a discretization for a nonlocal diffusion problem using a localized basis of radial basis functions. The stiffness matrix entries are assembled by a special quadrature routine unique to the localized basis. Combining the quadrature method with the localized basis produces a well-conditioned, sparse, symmetric positive definite stiffness matrix. We demonstrate that both the continuum and discrete problems are well-posed and present numerical results for the convergence behavior of the radial basis function method. As a result, we explore approximating the solution to anisotropic differential equations by solving anisotropic nonlocal integral equations using the radial basis function method.

  3. Uncertainty-induced quantum nonlocality

    NASA Astrophysics Data System (ADS)

    Wu, Shao-xiong; Zhang, Jun; Yu, Chang-shui; Song, He-shan

    2014-01-01

    Based on the skew information, we present a quantity, uncertainty-induced quantum nonlocality (UIN) to measure the quantum correlation. It can be considered as the updated version of the original measurement-induced nonlocality (MIN) preserving the good computability but eliminating the non-contractivity problem. For 2×d-dimensional state, it is shown that UIN can be given by a closed form. In addition, we also investigate the maximal uncertainty-induced nonlocality.

  4. Asymptotic Analysis of a Slightly Rarefied Gas with Nonlocal Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Caflisch, Russel E.; Lombardo, Maria Carmela; Sammartino, Marco

    2011-05-01

    In this paper nonlocal boundary conditions for the Navier-Stokes equations are derived, starting from the Boltzmann equation in the limit for the Knudsen number being vanishingly small. In the same spirit of (Lombardo et al. in J. Stat. Phys. 130:69-82, 2008) where a nonlocal Poisson scattering kernel was introduced, a gaussian scattering kernel which models nonlocal interactions between the gas molecules and the wall boundary is proposed. It is proved to satisfy the global mass conservation and a generalized reciprocity relation. The asymptotic expansion of the boundary-value problem for the Boltzmann equation, provides, in the continuum limit, the Navier-Stokes equations associated with a class of nonlocal boundary conditions of the type used in turbulence modeling.

  5. On an Inviscid Model for Incompressible Two-Phase Flows with Nonlocal Interaction

    NASA Astrophysics Data System (ADS)

    Gal, Ciprian G.

    2016-03-01

    We consider a diffuse interface model which describes the motion of an ideal incompressible mixture of two immiscible fluids with nonlocal interaction in two-dimensional bounded domains. This model consists of the Euler equation coupled with a convective nonlocal Cahn-Hilliard equation. We establish the existence of globally defined weak solutions as well as well-posedness results for strong/classical solutions.

  6. (1+2)-dimensional strongly nonlocal solitons

    SciTech Connect

    Ouyang Shigen; Guo Qi

    2007-11-15

    Approximate solutions of (1+2)-dimensional strongly nonlocal solitons (SNSs) are presented. It is shown that the power of a SNS in a nematic liquid crystal is in direct proportion to the second power of the degree of nonlocality, the power of a SNS in a nonlocal medium with a logarithmic nonlocal response is in inverse proportion to the second power of its beamwidth, and the power of a SNS in a nonlocal medium with an sth-power decay nonlocal response is in direct proportion to the (s+2)th power of the degree of nonlocality.

  7. Phonons in nonlocal van der Waals density functional theory

    NASA Astrophysics Data System (ADS)

    Sabatini, Riccardo; Küçükbenli, Emine; Pham, Cong Huy; de Gironcoli, Stefano

    2016-06-01

    We extend the formulation of density functional perturbation theory to treat nonlocal density functionals, accounting for van der Waals interactions, in a rigorous and efficient way. We provide a general formalism, suitable for any functional in this family, and give specific equations for the most widely used ones. We then study the lattice dynamics of graphite, comparing several nonlocal functionals and the local density approximation, showing that our recent revision of the VV10 functional [R. Sabatini et al., Phys. Rev. B 87, 041108(R) (2013), 10.1103/PhysRevB.87.041108] gives the best comparison with experiments.

  8. Ring dark and antidark solitons in nonlocal media.

    PubMed

    Horikis, Theodoros P; Frantzeskakis, Dimitrios J

    2016-02-01

    Ring dark and antidark solitons in nonlocal media are found. These structures have, respectively, the form of annular dips or humps on top of a stable CW background, and exist in a weak or strong nonlocality regime, defined by the sign of a characteristic parameter. It is demonstrated analytically that these solitons satisfy an effective cylindrical Kadomtsev-Petviashvili (aka Johnson's) equation and, as such, can be written explicitly in closed form. Numerical simulations show that they propagate undistorted and undergo quasi-elastic collisions, attesting to their stability properties. PMID:26907429

  9. Bounds for nonlocality distillation protocols

    SciTech Connect

    Forster, Manuel

    2011-06-15

    Nonlocality can be quantified by the violation of a Bell inequality. Since this violation may be amplified by local operations, an alternative measure has been proposed--distillable nonlocality. The alternative measure is difficult to calculate exactly due to the double exponential growth of the parameter space. In this paper, we give a way to bound the distillable nonlocality of a resource by the solutions to a related optimization problem. Our upper bounds are exponentially easier to compute than the exact value and are shown to be meaningful in general and tight in some cases.

  10. Nonlocal anomalous Hall effect

    NASA Astrophysics Data System (ADS)

    Zhang, Shulei; Vignale, Giovanni

    Anomalous Hall effect (AHE) is a distinctive transport property of ferromagnetic metals arising from spin orbit coupling (SOC) in concert with spontaneous spin polarization. Nonetheless, recent experiments have shown that the effect also appears in a nonmagnetic metal in contact with a magnetic insulator. The main puzzle lies in the apparent absence of spin polarized electrons in the non-magnetic metal. Here, we theoretically demonstrate that the scattering of electrons from a rough metal-insulator interface is generally spin-dependent, which results in mutual conversion between spin and charge currents flowing in the plane of the layer. It is the current-carrying spin polarized electrons and the spin Hall effect in the bulk of the metal layer that conspire to generate the AH current. This novel AHE differs from the conventional one only in the spatial separation of the SOC and the magnetization, so we name it as nonlocal AHE. In contrast to other previously proposed mechanisms (e.g., spin Hall AHE and magnetic proximity effect (MPE)), the nonlocal AHE appears on the first order of spin Hall angle and does not rely on the induced moments in the metal layer, which make it experimentally detectable by contrasting the AH current directions of two layered structures such as Pt/Cu/YIG and β -Ta/Cu/YIG (with a thin inserted Cu layer to eliminate the MPE). We predict that the directions of the AH currents in these two trilayers would be opposite since the spin Hall angles of Pt and β -Ta are of opposite signs. Work supported by NSF Grants DMR-1406568.

  11. Nonlocal Transport in the Reversed Field Pinch

    SciTech Connect

    Spizzo, G.; White, R. B.; Cappello, S.; Marrelli, L.

    2009-09-21

    Several heuristic models for nonlocal transport in plasmas have been developed, but they have had a limited possibility of detailed comparision with experimental data. Nonlocal aspects introduced by the existence of a known spectrum of relatively stable saturated tearing modes in a low current reversed field pinch offers a unique possibility for such a study. A numerical modelling of the magnetic structure and associated particle transport is carried out for the reversed-field pinch experiment at the Consorzio RFX, Padova, Italy. A reproduction of the tearing mode spectrum with a guiding center code1 reliably reproduces the observed soft X-ray tomography. Following particle trajectories in the stochastic magnetic field shows the transport across the unperturbed flux surfaces to be due to a spectrum of Levy flights, with the details of the spectrum position dependent. The resulting transport is subdiffusive, and cannot be described by Rechester-Rosenbluth diffusion, which depends on a random phase approximation. If one attempts to fit the local transport phenomenologically, the subdiffusion can be fit with a combination of diffusion and inward pinch2. It is found that whereas passing particles explore the stochastic field and hence participate in Levy flights, the trapped particles experience normal neoclassical diffusion. A two fluid nonlocal Montroll equation is used to model this transport, with a Levy flight defined as the motion of an ion during the period that the pitch has one sign. The necessary input to the Montroll equation consists of a time distribution for the Levy flights, given by the pitch angle scattering operator, and a distribution of the flight distances, determined numerically using a guiding center code. Results are compared to experiment. The relation of this formulation to fractional kinetics is also described.

  12. Nonlocal reactive transport with physical, chemical, and biological heterogeneity

    NASA Astrophysics Data System (ADS)

    Hu, Bill X.; Cushman, John H.; Deng, Fei-Wen

    When a natural porous medium is viewed from an eulerian perspective, incomplete characterization of the hydraulic conductivity, chemical reactivity, and biological activity leads to nonlocal constitutive theories, irrespective of whether the medium has evolving heterogeneity with fluctuations over all scales. Within this framework a constitutive theory involving nonlocal dispersive and convective fluxes and nonlocal sources/sinks is developed for chemicals undergoing random linear nonequilibrium reactions and random equilibrium first-order decay in a random conductivity field. The resulting transport equations are solved exactly in Fourier-Laplace space and then numerically inverted to real space. Mean concentration contours and various spatial moments are presented graphically for several covariance structures. 1997 Published by Elsevier Science Ltd. All rights reserved

  13. Effects of nonlocal heat transport on laser implosion

    SciTech Connect

    Mima, K.; Honda, M.; Miyamoto, S.; Kato, S.

    1996-05-01

    A numerical simulation code describing the spherically symmetric implosion hydrodynamics has been developed to investigate the nonlocal heat transport effects on stable high velocity implosion and fast ignition. In the implosion simulation code HIMICO, the Fokker Planck equation for electron transport is solved to describe the nonlocal effects. For high ablation pressure implosion with a pressure higher than 200 Mbar, the isentrope is found higher by a factor 2 in the nonlocal transport model than in the Spitzer Harm model. As for the fast ignition simulation, the neutron yield for the high density compression with 10 KJ laser increases to be 20 times by injecting an additional heating pulse of 10 KJ with 1 psec. {copyright} {ital 1996 American Institute of Physics.}

  14. Highly nonlocal optical nonlinearities in atoms trapped near a waveguide

    NASA Astrophysics Data System (ADS)

    Shahmoon, Ephraim; Grisins, Pjotrs; Stimming, Hans Peter; Mazets, Igor; Kurizki, Gershon

    2016-05-01

    Nonlinear optical phenomena are typically local. Here we predict the possibility of highly nonlocal optical nonlinearities for light propagating in atomic media trapped near a nano-waveguide, where long-range interactions between the atoms can be tailored. When the atoms are in an electromagnetically-induced transparency configuration, the atomic interactions are translated to long-range interactions between photons and thus to highly nonlocal optical nonlinearities. We derive and analyze the governing nonlinear propagation equation, finding a roton-like excitation spectrum for light and the emergence of long-range order in its output intensity. These predictions open the door to studies of unexplored wave dynamics and many-body physics with highly-nonlocal interactions of optical fields in one dimension.

  15. Nonlocal Transport Model for Two-Component Plasmas

    NASA Astrophysics Data System (ADS)

    Zheng, Zhen

    My PhD thesis concerns nonlocal effects on the transport processes in two-component (electron and ion) plasmas. My objective is to construct a self-consistent nonlocal transport model that is applicable in fully-ionized homogeneous Maxwellian plasmas with small-amplitude perturbations for arbitrary particle collisionalities. The fundamental method starts with a rigorous solution of the full set of linearized Fokker-Planck kinetic equations with the Landau collision operators for two-component plasmas. Then a procedure is implemented for derivation of the linear fluid equations which are closed by the transport relations. Thereby a complete list of transport coefficients for each component is computed in the broad range of temporal and spatial scales. Some new transport coefficients are found from the nonlocal hydrodynamic formulation. Ion collisions are self-consistently included in all the calculations. The electric susceptibilities and dispersion relation can thus be derived from this linear nonlocal hydrodynamics for both isothermal and non-isothermal cases. With the aid of these formulations, some important plasma quantities are successfully calculated and some practical fitting formulae are proposed, i.e., the mode frequencies and damping rates of ion acoustic wave (IAW) and entropy wave (ENW). In addition, this linear nonlocal hydrodynamics has been applied to a derivation of the dynamic form factor S(k,w) that serves to describe and explain correctly the features of the frequency spectra observed in Thomson scattering experiments. The most significant accomplishment in my research work is a thorough investigation and a deep analysis of nonlocal ion effects on longitudinal low-frequency plasma fluctuations.

  16. (1 + 2)-Dimensional sub-strongly nonlocal spatial optical solitons: Perturbation method

    NASA Astrophysics Data System (ADS)

    Ren, Hongyan; Ouyang, Shigen; Guo, Qi; Wu, Lijun

    2007-07-01

    By extending the (1 + 1)-dimensional [(1 + 1)-D] perturbation method suggested by Ouyang et al. [S. Ouyang, Q. Guo, W. Hu, Phys. Rev. E. 74 (2006) 036622] to the (1 + 2)-D case, we obtain a fundamental soliton solution to the (1 + 2)-D nonlocal nonlinear Schrödinger equation (NNLSE) with a Gaussian-type response function for the sub-strongly nonlocal case. Numerical simulations show that the soliton solution obtained in this paper can describe the soliton states in both the sub-strongly nonlocal case and the strongly nonlocal case. It is found that the phase constant and the power of the (1 + 2)-D strongly nonlocal spatial optical soliton with a Gaussian-type response function are both in inverse proportion to the 4th power of its beam width.

  17. a New Nonlocal Beam Theory with Thickness Stretching Effect for Nanobeams

    NASA Astrophysics Data System (ADS)

    Tounsi, Abdelouahed; Benguediab, Soumia; Houari, Mohammed Sid Ahmed; Semmah, Abdelwahed

    2013-08-01

    This paper presents a new nonlocal thickness-stretching sinusoidal shear deformation beam theory for the static and vibration of nanobeams. The present model incorporates the length scale parameter (nonlocal parameter) which can capture the small scale effect, and it accounts for both shear deformation and thickness stretching effects by a sinusoidal variation of all displacements through the thickness without using shear correction factor. Based on the nonlocal differential constitutive relations of Eringen, the equations of motion of the nanobeam are derived using Hamilton's principle. The effects of nonlocal parameter, aspect ratio and the thickness stretching on the static and dynamic responses of the nanobeam are discussed. The theoretical development presented herein may serve as a reference for nonlocal theories as applied to the bending and dynamic behaviors of complex-nanobeam-system such as complex carbon nanotube system.

  18. Shear deformable deformation of carbon nanotubes based on a new analytical nonlocal Timoshenko beam nodel

    SciTech Connect

    Zhang, Jianming; Yang, Yang

    2015-03-10

    According to Hamilton’s principle, a new mathematical model and analytical solutions for nonlocal Timoshenko beam model (ANT) is established based on nonlocal elastic continuum theory when shear deformation and nonlocal effect are considered. The new ANT equilibrium equations and boundary conditions are derived for bending analysis of carbon nanotubes (CNTs) with simply supported, clamped and cantilever. The ANT deflection solutions demonstrate that the CNT stiffness is enhanced by the presence of nonlocal stress effects. Furthermore, the new ANT model concluded verifiable bending behaviors for a cantilever CNT with point load at the free end, which depends on the strength of nonlocal stress. Therefore, this new model will gives a better prediction for mechanical behaviors of nanostructures.

  19. Aspects of nonlocality in quantum field theory, quantum gravity and cosmology

    NASA Astrophysics Data System (ADS)

    Barvinsky, A. O.

    2015-01-01

    This paper contains a collection of essays on nonlocal phenomena in quantum field theory, gravity and cosmology. Mechanisms of nonlocal contributions to the quantum effective action are discussed within the covariant perturbation expansion in field strengths and spacetime curvatures. Euclidean version of the Schwinger-Keldysh technique for quantum expectation values is presented as a special rule of obtaining the nonlocal effective equations of motion for the mean quantum field from the Euclidean effective action. This rule is applied to a new model of ghost free nonlocal cosmology which can generate the de Sitter (dS) cosmological evolution at an arbitrary value of Λ — a model of dark energy with the dynamical scale selected by a kind of a scaling symmetry breaking mechanism. This model is shown to interpolate between the superhorizon phase of a scalar mediated gravity and the short distance general relativistic limit in a special metric frame related by a nonlocal conformal transformation to the original metric.

  20. On locally and nonlocally related potential systems

    NASA Astrophysics Data System (ADS)

    Cheviakov, Alexei F.; Bluman, George W.

    2010-07-01

    For any partial differential equation (PDE) system, a local conservation law yields potential equations in terms of some potential variable, which normally is a nonlocal variable. The current paper examines situations when such a potential variable is a local variable, i.e., is a function of the independent and dependent variables of a given PDE system, and their derivatives. In the case of two independent variables, a simple necessary and sufficient condition is presented for the locality of such a potential variable, and this is illustrated by several examples. As a particular example, two-dimensional reductions of equilibrium equations for fluid and plasma dynamics are considered. It is shown that such reductions with respect to helical, axial, and translational symmetries have conservation laws which yield local potential variables. This leads to showing that the well-known Johnson-Frieman-Kruskal-Oberman (JFKO) and Bragg-Hawthorne (Grad-Shafranov) equations are locally related to the corresponding helically and axially symmetric PDE systems of fluid/plasma dynamics. For the axially symmetric case, local symmetry classifications and arising invariant solutions are compared for the original PDE system and the Bragg-Hawthorne (potential) equation. The potential equation is shown to have additional symmetries, denoted as restricted symmetries. Restricted symmetries leave invariant a family of solutions of a given PDE system but not the whole solution manifold, and hence are not symmetries of the given PDE system. Corresponding reductions are shown to yield solutions, which are not obtained as invariant solutions from local symmetry reduction.

  1. Nonlocal Anomalous Hall Effect

    NASA Astrophysics Data System (ADS)

    Zhang, Steven S.-L.; Vignale, Giovanni

    2016-04-01

    The anomalous Hall (AH) effect is deemed to be a unique transport property of ferromagnetic metals, caused by the concerted action of spin polarization and spin-orbit coupling. Nevertheless, recent experiments have shown that the effect also occurs in a nonmagnetic metal (Pt) in contact with a magnetic insulator [yttrium iron garnet (YIG)], even when precautions are taken to ensure that there is no induced magnetization in the metal. We propose a theory of this effect based on the combined action of spin-dependent scattering from the magnetic interface and the spin-Hall effect in the bulk of the metal. At variance with previous theories, we predict the effect to be of first order in the spin-orbit coupling, just as the conventional anomalous Hall effect—the only difference being the spatial separation of the spin-orbit interaction and the magnetization. For this reason we name this effect the nonlocal anomalous Hall effect and predict that its sign will be determined by the sign of the spin-Hall angle in the metal. The AH conductivity that we calculate from our theory is in order of magnitude agreement with the measured values in Pt /YIG structures.

  2. Nonlocal Intracranial Cavity Extraction

    PubMed Central

    Manjón, José V.; Eskildsen, Simon F.; Coupé, Pierrick; Romero, José E.; Collins, D. Louis; Robles, Montserrat

    2014-01-01

    Automatic and accurate methods to estimate normalized regional brain volumes from MRI data are valuable tools which may help to obtain an objective diagnosis and followup of many neurological diseases. To estimate such regional brain volumes, the intracranial cavity volume (ICV) is often used for normalization. However, the high variability of brain shape and size due to normal intersubject variability, normal changes occurring over the lifespan, and abnormal changes due to disease makes the ICV estimation problem challenging. In this paper, we present a new approach to perform ICV extraction based on the use of a library of prelabeled brain images to capture the large variability of brain shapes. To this end, an improved nonlocal label fusion scheme based on BEaST technique is proposed to increase the accuracy of the ICV estimation. The proposed method is compared with recent state-of-the-art methods and the results demonstrate an improved performance both in terms of accuracy and reproducibility while maintaining a reduced computational burden. PMID:25328511

  3. Bipartite units of nonlocality

    SciTech Connect

    Forster, Manuel; Wolf, Stefan

    2011-10-15

    Imagine a task in which a group of separated players aim to simulate a statistic that violates a Bell inequality. Given measurement choices the players shall announce an output based solely on the results of local operations--which they can discuss before the separation--on shared random data and shared copies of a so-called unit correlation. In the first part of this paper we show that in such a setting the simulation of any bipartite correlation, not containing the possibility of signaling, can be made arbitrarily accurate by increasing the number of shared Popescu-Rohrlich (PR) boxes. This establishes the PR box as a simple asymptotic unit of bipartite nonlocality. In the second part we study whether this property extends to the multipartite case. More generally, we ask if it is possible for separated players to asymptotically reproduce any nonsignaling statistic by local operations on bipartite unit correlations. We find that nonadaptive strategies are limited by a constant accuracy and that arbitrary strategies on n resource correlations make a mistake with a probability greater or equal to c/n, for some constant c.

  4. Fast separable nonlocal means

    NASA Astrophysics Data System (ADS)

    Ghosh, Sanjay; Chaudhury, Kunal N.

    2016-03-01

    We propose a simple and fast algorithm called PatchLift for computing distances between patches (contiguous block of samples) extracted from a given one-dimensional signal. PatchLift is based on the observation that the patch distances can be efficiently computed from a matrix that is derived from the one-dimensional signal using lifting; importantly, the number of operations required to compute the patch distances using this approach does not scale with the patch length. We next demonstrate how PatchLift can be used for patch-based denoising of images corrupted with Gaussian noise. In particular, we propose a separable formulation of the classical nonlocal means (NLM) algorithm that can be implemented using PatchLift. We demonstrate that the PatchLift-based implementation of separable NLM is a few orders faster than standard NLM and is competitive with existing fast implementations of NLM. Moreover, its denoising performance is shown to be consistently superior to that of NLM and some of its variants, both in terms of peak signal-to-noise ratio/structural similarity index and visual quality.

  5. Nonlocal optical response in metallic nanostructures.

    PubMed

    Raza, Søren; Bozhevolnyi, Sergey I; Wubs, Martijn; Asger Mortensen, N

    2015-05-13

    This review provides a broad overview of the studies and effects of nonlocal response in metallic nanostructures. In particular, we thoroughly present the nonlocal hydrodynamic model and the recently introduced generalized nonlocal optical response (GNOR) model. The influence of nonlocal response on plasmonic excitations is studied in key metallic geometries, such as spheres and dimers, and we derive new consequences due to the GNOR model. Finally, we propose several trajectories for future work on nonlocal response, including experimental setups that may unveil further effects of nonlocal response. PMID:25893883

  6. Towards LHC physics with nonlocal Standard Model

    NASA Astrophysics Data System (ADS)

    Biswas, Tirthabir; Okada, Nobuchika

    2015-09-01

    We take a few steps towards constructing a string-inspired nonlocal extension of the Standard Model. We start by illustrating how quantum loop calculations can be performed in nonlocal scalar field theory. In particular, we show the potential to address the hierarchy problem in the nonlocal framework. Next, we construct a nonlocal abelian gauge model and derive modifications of the gauge interaction vertex and field propagators. We apply the modifications to a toy version of the nonlocal Standard Model and investigate collider phenomenology. We find the lower bound on the scale of nonlocality from the 8 TeV LHC data to be 2.5-3 TeV.

  7. A model for the nonlocal transport and the associated distribution function deformation in magnetized laser-plasmas

    NASA Astrophysics Data System (ADS)

    Nicolaï, Ph.; Feugeas, J.-L.; Schurtz, G.

    2006-06-01

    We present a model of nonlocal transport for multidimensional radiation magneto hydrodynamic codes. In laser produced plasmas, it is now believed that the heat transfert can be strongly modified by the nonlocal nature of the electron conduction. Nevertheless other mechanisms as self generated magnetic fields may affect heat transport too. The model described in this work aims at extending the formula of G. Schurtz, Ph. Nicolaï and M. Busquet [1] to magnetized plasmas. A system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and applied to a physical problem in order to demonstrate the main features of the model.

  8. Nonlocal electron transport in magnetized plasmas with arbitrary atomic number

    SciTech Connect

    Bennaceur-Doumaz, D.; Bendib, A.

    2006-09-15

    The numerical solution of the steady-state electron Fokker-Planck equation perturbed with respect to a global equilibrium is presented in magnetized plasmas with arbitrary atomic number Z. The magnetic field is assumed to be constant and the electron-electron collisions are described by the Landau collision operator. The solution is derived in the Fourier space and in the framework of the diffusive approximation which captures the spatial nonlocal effects. The transport coefficients are deduced and used to close a complete set of nonlocal electron fluid equations. This work improves the results of A. Bendib et al. [Phys. Plasmas 9, 1555 (2002)] and of A. V. Brantov et al. [Phys. Plasmas 10, 4633 (2003)] restricted to the local and nonlocal high-Z plasma approximations, respectively. The influence of the magnetic field on the nonlocal effects is discussed. We propose also accurate numerical fits of the relevant transport coefficients with respect to the collisionality parameter {lambda}{sub ei}/L and the atomic number Z, where L is the typical scale length and {lambda}{sub ei} is the electron-ion mean-free-path.

  9. Nonlocal Measurements via Quantum Erasure

    NASA Astrophysics Data System (ADS)

    Brodutch, Aharon; Cohen, Eliahu

    2016-02-01

    Nonlocal observables play an important role in quantum theory, from Bell inequalities and various postselection paradoxes to quantum error correction codes. Instantaneous measurement of these observables is known to be a difficult problem, especially when the measurements are projective. The standard von Neumann Hamiltonian used to model projective measurements cannot be implemented directly in a nonlocal scenario and can, in some cases, violate causality. We present a scheme for effectively generating the von Neumann Hamiltonian for nonlocal observables without the need to communicate and adapt. The protocol can be used to perform weak and strong (projective) measurements, as well as measurements at any intermediate strength. It can also be used in practical situations beyond nonlocal measurements. We show how the protocol can be used to probe a version of Hardy's paradox with both weak and strong measurements. The outcomes of these measurements provide a nonintuitive picture of the pre- and postselected system. Our results shed new light on the interplay between quantum measurements, uncertainty, nonlocality, causality, and determinism.

  10. Nonlocal Measurements via Quantum Erasure.

    PubMed

    Brodutch, Aharon; Cohen, Eliahu

    2016-02-19

    Nonlocal observables play an important role in quantum theory, from Bell inequalities and various postselection paradoxes to quantum error correction codes. Instantaneous measurement of these observables is known to be a difficult problem, especially when the measurements are projective. The standard von Neumann Hamiltonian used to model projective measurements cannot be implemented directly in a nonlocal scenario and can, in some cases, violate causality. We present a scheme for effectively generating the von Neumann Hamiltonian for nonlocal observables without the need to communicate and adapt. The protocol can be used to perform weak and strong (projective) measurements, as well as measurements at any intermediate strength. It can also be used in practical situations beyond nonlocal measurements. We show how the protocol can be used to probe a version of Hardy's paradox with both weak and strong measurements. The outcomes of these measurements provide a nonintuitive picture of the pre- and postselected system. Our results shed new light on the interplay between quantum measurements, uncertainty, nonlocality, causality, and determinism. PMID:26943514

  11. Alleviation of catastrophic quenching in solar dynamo model with nonlocal alpha-effect

    NASA Astrophysics Data System (ADS)

    Kitchatinov, L. L.; Olemskoy, S. V.

    2011-06-01

    The nonlocal alpha-effect of Babcock-Leighton type is not prone to the catastrophic quenching due to conservation of magnetic helicity. This is shown with a dynamo model, which jointly applies the nonlocal alpha-effect, the diamagnetic pumping, and dynamical equation for the magnetic alpha-effect. The same model shows catastrophic quenching when the alpha-effect is changed to its local formulation. The nonlocal model shows a preferred excitation of magnetic fields of dipolar symmetry, which oscillate with a period of about ten years and have a toroidal-to-polar fields ratio of about a thousand.

  12. Localization of the SFT inspired nonlocal linear models and exact solutions

    NASA Astrophysics Data System (ADS)

    Vernov, S. Yu.

    2011-05-01

    A general class of gravitational models driven by a nonlocal scalar field with a linear or quadratic potential is considered. We study the action with an arbitrary analytic function ℱ(□ g ), which has both simple and double roots. The way of localization of nonlocal Einstein equations is generalized on models with linear potentials. Exact solutions in the Friedmann-Robertson-Walker and Bianchi I metrics are presented.

  13. Closed sets of nonlocal correlations

    SciTech Connect

    Allcock, Jonathan; Linden, Noah; Brunner, Nicolas; Popescu, Sandu; Skrzypczyk, Paul; Vertesi, Tamas

    2009-12-15

    We present a fundamental concept - closed sets of correlations - for studying nonlocal correlations. We argue that sets of correlations corresponding to information-theoretic principles, or more generally to consistent physical theories, must be closed under a natural set of operations. Hence, studying the closure of sets of correlations gives insight into which information-theoretic principles are genuinely different, and which are ultimately equivalent. This concept also has implications for understanding why quantum nonlocality is limited, and for finding constraints on physical theories beyond quantum mechanics.

  14. Strong Local-Nonlocal Coupling for Integrated Fracture Modeling

    SciTech Connect

    Littlewood, David John; Silling, Stewart A.; Mitchell, John A.; Seleson, Pablo D.; Bond, Stephen D.; Parks, Michael L.; Turner, Daniel Z.; Burnett, Damon J.; Ostien, Jakob; Gunzburger, Max

    2015-09-01

    Peridynamics, a nonlocal extension of continuum mechanics, is unique in its ability to capture pervasive material failure. Its use in the majority of system-level analyses carried out at Sandia, however, is severely limited, due in large part to computational expense and the challenge posed by the imposition of nonlocal boundary conditions. Combined analyses in which peridynamics is em- ployed only in regions susceptible to material failure are therefore highly desirable, yet available coupling strategies have remained severely limited. This report is a summary of the Laboratory Directed Research and Development (LDRD) project "Strong Local-Nonlocal Coupling for Inte- grated Fracture Modeling," completed within the Computing and Information Sciences (CIS) In- vestment Area at Sandia National Laboratories. A number of challenges inherent to coupling local and nonlocal models are addressed. A primary result is the extension of peridynamics to facilitate a variable nonlocal length scale. This approach, termed the peridynamic partial stress, can greatly reduce the mathematical incompatibility between local and nonlocal equations through reduction of the peridynamic horizon in the vicinity of a model interface. A second result is the formulation of a blending-based coupling approach that may be applied either as the primary coupling strategy, or in combination with the peridynamic partial stress. This blending-based approach is distinct from general blending methods, such as the Arlequin approach, in that it is specific to the coupling of peridynamics and classical continuum mechanics. Facilitating the coupling of peridynamics and classical continuum mechanics has also required innovations aimed directly at peridynamic models. Specifically, the properties of peridynamic constitutive models near domain boundaries and shortcomings in available discretization strategies have been addressed. The results are a class of position-aware peridynamic constitutive laws for

  15. Structure formation in a nonlocally modified gravity model

    SciTech Connect

    Park, Sohyun; Dodelson, Scott

    2013-01-01

    We study a nonlocally modified gravity model proposed by Deser and Woodard which gives an explanation for current cosmic acceleration. By deriving and solving the equations governing the evolution of the structure in the Universe, we show that this model predicts a pattern of growth that differs from standard general relativity (+dark energy) at the 10-30% level. These differences will be easily probed by the next generation of galaxy surveys, so the model should be tested shortly.

  16. Maxwell-Garnett effective medium theory: Quantum nonlocal effects

    SciTech Connect

    Moradi, Afshin

    2015-04-15

    We develop the Maxwell-Garnett theory for the effective medium approximation of composite materials with metallic nanoparticles by taking into account the quantum spatial dispersion effects in dielectric response of nanoparticles. We derive a quantum nonlocal generalization of the standard Maxwell-Garnett formula, by means the linearized quantum hydrodynamic theory in conjunction with the Poisson equation as well as the appropriate additional quantum boundary conditions.

  17. Stereopsis from contrast envelopes.

    PubMed

    Langley, K; Fleet, D J; Hibbard, P B

    1999-07-01

    We report two experiments concerning the site of the principal nonlinearity in second-order stereopsis. The first exploits the asymmetry in perceiving transparency with second-order stimuli found by Langley et al. (1998) (Proceedings of the Royal Society of London B, 265, 1837-1845) i.e. the product of a positive-valued contrast envelope and a mean-zero carrier grating can be seen transparently only when the disparities are consistent with the envelope appearing in front of the carrier. We measured the energy at the envelope frequencies that must be added in order to negate this asymmetry. We report that this amplitude can be predicted from the envelope sidebands and not from the magnitude of compressive pre-cortical nonlinearities measured by other researchers. In the second experiment, contrast threshold elevations were measured for the discrimination of envelope disparities following adaptation to sinusoidal gratings. It is reported that perception of the envelope's depth was affected most when the adapting grating was similar (in orientation and frequency) to the carrier, rather than to the contrast envelope. These results suggest that the principal nonlinearity in second-order stereopsis is cortical, occurring after orientation- and frequency-selective linear filtering. PMID:10367053

  18. Weakly nonlocal hydrodynamics and the origin of viscosity in the adhesion model

    SciTech Connect

    Ribeiro, A.L.B.; Peixoto de Faria, J.G.

    2005-03-15

    We use the weakly nonlocal hydrodynamics approach to obtain a dynamical equation for the peculiar velocity field in which the viscosity term is physically motivated. Based on some properties of the Ginzburg-Landau equation and the wave mechanics analog of hydrodynamics we find the nonlocal adhesion approximation taking into account the internal structures of the Zeldovich pancakes. If the internal structures correspond to significant mesoscopic fluctuations, viscosity is probably driven by a stochastic force and dynamics is given by the noisy Burgers equation.

  19. Non-local rheology for dense granular flows in avalanches

    NASA Astrophysics Data System (ADS)

    Izzet, Adrien; Clement, Eric; Andreotti, Bruno

    A local constitutive relation was proposed to describe dense granular flows (GDR MiDi, EPJE 2004). It provides a rather good prediction of the flowing regime but does not foresee the existence of a ``creep regime'' as observed by Komatsu et al. (PRL 2001). In the context of a 2D shear cell, a relaxation length for the velocity profile was measured (Bouzid et al., PRL 2013) which confirmed the existence of a flow below the standard Coulomb yield threshold. A correction for the local rheology was proposed. To test further this non-local constitutive relation, we built an inclined narrow channel within which we monitor the flow from the side. We managed to observe the ``creep regime'' over five orders of magnitude in velocity and fit the velocity profiles in the depth with an asymptotic solution of the non-local equation. However, the boundary condition at the free surface needs to be selected in order to calibrate the non-local rheology over the whole range of stresses in the system. In this perspective, we complement the experimental results with 2D simulations of hard and frictional discs on an inclined plane in which we introduce a surface friction force proportional to the effective pressure in the granular. We analyze these results in the light of the non-local rheology.

  20. Plastic failure of nonlocal beams.

    PubMed

    Challamel, Noël; Lanos, Christophe; Casandjian, Charles

    2008-08-01

    This paper questions the mode of collapse of some simple softening nonlocal structural systems comprising the classical cantilever beam. Nanobeams can be concerned by such an elementary model. The homogeneous cantilever beam loaded by a concentrated force at its extremity is first considered as a structural paradigm. A nonlocal plasticity model is developed in order to control the localization process induced by microcracking phenomena. An implicit gradient plasticity model equivalent to a nonlocal integral plasticity model is used in this paper. It is shown that the regularized problem is well posed. Closed-form solutions of the elastoplastic deflection are finally derived. The length of the plastic zone grows during the softening process until an asymptotic limited value, which depends on the characteristic length of the material. Scale effects are clearly obtained for these static bending tests. Other structural cases are also presented, including the simply supported beam under uniform transverse loading. It is concluded that the mode of collapse is firmly a nonlocal phenomenon. PMID:18850959

  1. On nonlocal electron heat conduction

    SciTech Connect

    Krasheninnikov, S.I. )

    1993-01-01

    An improvement of the Albritton nonlocal electron heat transport model is proposed for high-[ital Z] plasmas. The thermal decay of the temperature perturbation in a uniform plasma as calculated by this model is compared with that obtained by Fokker--Planck simulations. Complete agreement is found up to values [ital k][lambda][sub [ital e

  2. Learning Non-Local Dependencies

    ERIC Educational Resources Information Center

    Kuhn, Gustav; Dienes, Zoltan

    2008-01-01

    This paper addresses the nature of the temporary storage buffer used in implicit or statistical learning. Kuhn and Dienes [Kuhn, G., & Dienes, Z. (2005). Implicit learning of nonlocal musical rules: implicitly learning more than chunks. "Journal of Experimental Psychology-Learning Memory and Cognition," 31(6) 1417-1432] showed that people could…

  3. Free vibration analysis of a multiple rotating nano-beams system based on the Eringen nonlocal elasticity theory

    NASA Astrophysics Data System (ADS)

    Ghafarian, M.; Ariaei, A.

    2016-08-01

    The free vibration analysis of a multiple rotating nanobeams' system applying the nonlocal Eringen elasticity theory is presented. Multiple nanobeams' systems are of great importance in nano-optomechanical applications. At nanoscale, the nonlocal effects become non-negligible. According to the nonlocal Euler-Bernoulli beam theory, the governing partial differential equations are derived by incorporating the nonlocal scale effects. Assuming a structure of n parallel nanobeams, the vibration of the system is described by a coupled set of n partial differential equations. The method involves a change of variables to uncouple the equations and the differential transform method as an efficient mathematical technique to solve the nonlocal governing differential equations. Then a number of parametric studies are conducted to assess the effect of the nonlocal scaling parameter, rotational speed, boundary conditions, hub radius, and the stiffness coefficients of the elastic interlayer media on the vibration behavior of the coupled rotating multiple-carbon-nanotube-beam system. It is revealed that the bending vibration of the system is significantly influenced by the rotational speed, elastic mediums, and the nonlocal scaling parameters. This model is validated by comparing the results with those available in the literature. The natural frequencies are in a reasonably good agreement with the reported results.

  4. The solar envelope

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.

    1971-01-01

    Processes which occur within the region between approximately 2 solar radii and 25 solar radii, which is called the solar envelope and the effect on the solar wind as seen at 1 AU are discussed. In the envelope the wind speed becomes supersonic and super-Alfvenic, the magnetic energy density is larger than the flow energy density, and the magnetic energy density is much larger than the thermal energy density. Large azimuthal gradients in the bulk speed are expected in the envelope, but the stream interactions near the outer edge of the envelope are probably relatively small. Cosmic ray observations suggest the presence of hydromagnetic waves in the envelope. The collisionless damping of such waves could heat protons out to approximately 25 solar radii and thereby cause an increase in V and T sub p consistent with the observed T sub p -V relation. A mechanism which couples protons and electrons would also heat and accelerate the wind. Alfven waves can accelerate the wind in the envelope without necessarily causing heating of protons; the Lorentz force might have a similar effect.

  5. A coupling strategy for nonlocal and local diffusion models with mixed volume constraints and boundary conditions

    SciTech Connect

    D'Elia, Marta; Perego, Mauro; Bochev, Pavel B.; Littlewood, David John

    2015-12-21

    We develop and analyze an optimization-based method for the coupling of nonlocal and local diffusion problems with mixed volume constraints and boundary conditions. The approach formulates the coupling as a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of the nonlocal and local domains, and the controls are virtual volume constraints and boundary conditions. When some assumptions on the kernel functions hold, we prove that the resulting optimization problem is well-posed and discuss its implementation using Sandia’s agile software components toolkit. As a result, the latter provides the groundwork for the development of engineering analysis tools, while numerical results for nonlocal diffusion in three-dimensions illustrate key properties of the optimization-based coupling method.

  6. A coupling strategy for nonlocal and local diffusion models with mixed volume constraints and boundary conditions

    DOE PAGESBeta

    D'Elia, Marta; Perego, Mauro; Bochev, Pavel B.; Littlewood, David John

    2015-12-21

    We develop and analyze an optimization-based method for the coupling of nonlocal and local diffusion problems with mixed volume constraints and boundary conditions. The approach formulates the coupling as a control problem where the states are the solutions of the nonlocal and local equations, the objective is to minimize their mismatch on the overlap of the nonlocal and local domains, and the controls are virtual volume constraints and boundary conditions. When some assumptions on the kernel functions hold, we prove that the resulting optimization problem is well-posed and discuss its implementation using Sandia’s agile software components toolkit. As a result,more » the latter provides the groundwork for the development of engineering analysis tools, while numerical results for nonlocal diffusion in three-dimensions illustrate key properties of the optimization-based coupling method.« less

  7. Quadrature rules for finite element approximations of 1D nonlocal problems

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoping; Gunzburger, Max; Ju, Lili

    2016-04-01

    It is well known that calculations of the entries of the stiffness matrix in the finite element approximations of nonlocal diffusion and mechanics models are often very time-consuming due to the double integration process over the domain and the singularities of the nonlocal kernel functions. In this paper, we propose some effective and accurate quadrature rules for computing these double integrals for one-dimensional nonlocal problems; in particular, for problems with highly singular kernels, the corresponding inner integrals can be first evaluated exactly in our method, and the outer one then will be approximated by some popular quadrature rules. With these quadrature rules, the assembly of the stiffness matrix in the finite element method for the nonlocal problems becomes similar to that for the classical partial differential equations and is thus quite efficient.

  8. Influence of nonlocal damping on the field-driven domain wall motion

    NASA Astrophysics Data System (ADS)

    Yuan, H. Y.; Yuan, Zhe; Xia, Ke; Wang, X. R.

    2016-08-01

    We derive a general expression of nonlocal damping in noncollinear magnetization due to the nonuniform spin current pumped by precessional magnetization and incorporate it into a generalized Thiele equation to study its effects on the dynamics of the transverse and vortex domain walls (DWs) in ferromagnetic nanowires. We demonstrate that the transverse component of nonlocal damping slows down the field-driven DW propagation and increases the Walker breakdown field, whereas it is neglected in many previous works in literature. The experimentally measured DW mobility variation with the damping tuned by doping with heavy rare-earth elements that had discrepancy from micromagnetic simulation is now well understood with the nonlocal damping. Our results suggest that the nonlocal damping should be properly included as a prerequisite for quantitative studies of current-induced torques in noncollinear magnetization.

  9. Non-local dynamics governing the self-induced motion of a planar vortex filament

    NASA Astrophysics Data System (ADS)

    Van Gorder, Robert A.

    2015-06-01

    While the Hasimoto planar vortex filament is one of the few exact solutions to the local induction approximation (LIA) approximating the self-induced motion of a vortex filament, it is natural to wonder whether such a vortex filament solution would exist for the non-local Biot-Savart dynamics exactly governing the filament motion, and if so, whether the non-local effects would drastically modify the solution properties. Both helical vortex filaments and vortex rings are known to exist under both the LIA and non-local Biot-Savart dynamics; however, the planar filament is a bit more complicated. In the present paper, we demonstrate that a planar vortex filament solution does exist for the non-local Biot-Savart formulation, provided that a specific non-linear integral equation (governing the spatial structure of such a filament) has a non-trivial solution. By using the Poincaré-Lindstedt method, we are able to obtain an accurate analytical approximation to the solution of this integral equation under physically reasonable assumptions. To obtain these solutions, we approximate local effects near the singularity of the integral equation using the LIA and non-local effects using the Biot-Savart formulation. Mathematically, the results constitute an analytical solution to an interesting nonlinear singular integro-differential equation in space and time variables. Physically, these results show that planar vortex filaments exist and maintain their forms under the non-local Biot-Savart formulation, as one would hope. Due to the regularization approach utilized, we are able to compare the structure of the planar filaments obtained under both LIA and Biot-Savart formulations in a rather straightforward manner, in order to determine the role of the non-locality on the structure of the planar filament.

  10. CTE Solvability, Nonlocal Symmetry and Explicit Solutions of Modified Boussinesq System

    NASA Astrophysics Data System (ADS)

    Ren, Bo; Cheng, Xue-Ping

    2016-07-01

    A consistent tanh expansion (CTE) method is used to study the modified Boussinesq equation. It is proved that the modified Boussinesq equation is CTE solvable. The soliton-cnoidal periodic wave is explicitly given by a nonanto-BT theorem. Furthermore, the nonlocal symmetry for the modified Boussinesq equation is obtained by the Painlevé analysis. The nonlocal symmetry is localized to the Lie point symmetry by introducing one auxiliary dependent variable. The finite symmetry transformation related with the nonlocal symemtry is obtained by solving the initial value problem of the prolonged systems. Thanks to the localization process, many interaction solutions among solitons and other complicated waves are computed through similarity reductions. Some special concrete soliton-cnoidal wave interaction behaviors are studied both in analytical and graphical ways. Supported by the National Natural Science Foundation of China under Grant Nos. 11305106 and 11505154

  11. Nonlocality and conflicting interest games.

    PubMed

    Pappa, Anna; Kumar, Niraj; Lawson, Thomas; Santha, Miklos; Zhang, Shengyu; Diamanti, Eleni; Kerenidis, Iordanis

    2015-01-16

    Nonlocality enables two parties to win specific games with probabilities strictly higher than allowed by any classical theory. Nevertheless, all known such examples consider games where the two parties have a common interest, since they jointly win or lose the game. The main question we ask here is whether the nonlocal feature of quantum mechanics can offer an advantage in a scenario where the two parties have conflicting interests. We answer this in the affirmative by presenting a simple conflicting interest game, where quantum strategies outperform classical ones. Moreover, we show that our game has a fair quantum equilibrium with higher payoffs for both players than in any fair classical equilibrium. Finally, we play the game using a commercial entangled photon source and demonstrate experimentally the quantum advantage. PMID:25635538

  12. Optimal protocols for nonlocality distillation

    SciTech Connect

    Hoeyer, Peter; Rashid, Jibran

    2010-10-15

    Forster et al. recently showed that weak nonlocality can be amplified by giving the first protocol that distills a class of nonlocal boxes (NLBs) [Phys. Rev. Lett. 102, 120401 (2009)] We first show that their protocol is optimal among all nonadaptive protocols. We next consider adaptive protocols. We show that the depth-2 protocol of Allcock et al. [Phys. Rev. A 80, 062107 (2009)] performs better than previously known adaptive depth-2 protocols for all symmetric NLBs. We present a depth-3 protocol that extends the known region of distillable NLBs. We give examples of NLBs for which each of the Forster et al., the Allcock et al., and our protocols perform best. The understanding we develop is that there is no single optimal protocol for NLB distillation. The choice of which protocol to use depends on the noise parameters for the NLB.

  13. Randomness versus nonlocality and entanglement.

    PubMed

    Acín, Antonio; Massar, Serge; Pironio, Stefano

    2012-03-01

    The outcomes obtained in Bell tests involving two-outcome measurements on two subsystems can, in principle, generate up to 2 bits of randomness. However, the maximal violation of the Clauser-Horne-Shimony-Holt inequality guarantees the generation of only 1.23 bits of randomness. We prove here that quantum correlations with arbitrarily little nonlocality and states with arbitrarily little entanglement can be used to certify that close to the maximum of 2 bits of randomness are produced. Our results show that nonlocality, entanglement, and randomness are inequivalent quantities. They also imply that device-independent quantum key distribution with an optimal key generation rate is possible by using almost-local correlations and that device-independent randomness generation with an optimal rate is possible with almost-local correlations and with almost-unentangled states. PMID:22463395

  14. Certifying nonlocality from separable marginals

    NASA Astrophysics Data System (ADS)

    Vértesi, Tamás; Laskowski, Wiesław; Pál, Károly F.

    2014-01-01

    Imagine three parties, Alice, Bob, and Charlie, who share a state of three qubits such that all two-party reduced states A-B, A-C, and B-C are separable. Suppose that they have information only about these marginals but not about the global state. According to recent results, there exists an example for a set of three separable two-party reduced states that is only compatible with an entangled global state. In this paper, we show a stronger result by exhibiting separable two-party reduced states A-B, A-C, and B-C, such that any global state compatible with these marginals is nonlocal. Hence, we obtain that nonlocality of multipartite states can be certified from information only about separable marginals.

  15. Activation of nonlocal quantum resources.

    PubMed

    Navascués, Miguel; Vértesi, Tamás

    2011-02-11

    We find two two-qubit bipartite states ρ1, ρ2 such that arbitrarily many copies of one or the other cannot exhibit nonlocal correlations in a two-setting-two-outcome Bell scenario. However, the bipartite state ρ1 ⊗ ρ2 violates the Clauser-Horne-Shimony-Holt (CHSH) Bell inequality [J. F. Clauser, M. A. Horne, A. Shimony, and R. A. Holt, Phys. Rev. Lett. 23, 880 (1969).] by an amount of 2.023. We also identify a CHSH-local state ρ such that ρ⊗2 is CHSH inequality-violating. The tools employed can be easily adapted to find instances of nonlocality activation in arbitrary Bell scenarios. PMID:21405447

  16. Temporal nonlocality in bistable perception

    NASA Astrophysics Data System (ADS)

    Atmanspacher, Harald; Filk, Thomas

    2012-12-01

    A novel conceptual framework for theoretical psychology is presented and illustrated for the example of bistable perception. A basic formal feature of this framework is the non-commutativity of operations acting on mental states. A corresponding model for the bistable perception of ambiguous stimuli, the Necker-Zeno model, is sketched and some empirical evidence for it so far is described. It is discussed how a temporal nonlocality of mental states, predicted by the model, can be understood and tested.

  17. Strong nonlocalization induced by small scale parameter on terahertz flexural wave dispersion characteristics of a monolayer graphene

    NASA Astrophysics Data System (ADS)

    Narendar, S.; Gopalakrishnan, S.

    2010-11-01

    This paper presents the strong nonlocal scale effect on the flexural wave propagation in a monolayer graphene sheet. The graphene is modeled as an isotropic plate of one atom thick. Nonlocal governing equation of motion is derived and wave propagation analysis is performed using spectral analysis. The present analysis shows that the flexural wave dispersion in graphene obtained by local and nonlocal elasticity theories is quite different. The nonlocal elasticity calculation shows that the wavenumber escapes to infinite at certain frequency and the corresponding wave velocity tends to zero at that frequency indicating localization and stationary behavior. This behavior is captured in the spectrum and dispersion curves. The cut-off frequency of flexural wave not only depend on the axial wavenumber but also on the nonlocal scaling parameter. The effect of axial wavenumber on the wave behavior in graphene is also discussed in the present manuscript.

  18. Serendipitous discoveries in nonlocal gravity theory

    NASA Astrophysics Data System (ADS)

    Barvinsky, A. O.

    2012-05-01

    We present a class of generally covariant nonlocal gravity models which have a flat-space general relativistic limit and also possess a stable de Sitter or anti-de Sitter (AdS) background with an arbitrary value of its cosmological constant. The nonlocal action of the theory is formulated in the Euclidean signature spacetime and is understood as an approximation to the quantum effective action (generating functional of one-particle irreducible diagrams) originating from fundamental quantum gravity theory. Using the known relation between the Schwinger-Keldysh technique for quantum expectation values and the Euclidean quantum field theory we derive from this action the causal effective equations of motion for mean value of the metric field in the physical Lorentzian-signature spacetime. Thus we show that the (A)dS background of the theory carries as free propagating modes massless gravitons having two polarizations identical to those of the Einstein theory with a cosmological term. The on-shell action of the theory is vanishing both for the flat-space and (A)dS backgrounds which play the role of stable vacua underlying, respectively, the ultraviolet and infrared phases of the theory. We also obtain linearized gravitational potentials of compact matter sources and show that in the infrared (A)dS phase their effective gravitational coupling Geff can be essentially different from the Newton gravitational constant GN of the short-distance general relativistic phase. When Geff≫GN the (A)dS phase can be regarded as a strongly coupled infrared modification of Einstein theory not only describing the dark energy mechanism of cosmic acceleration but also simulating the dark matter phenomenon by enhanced gravitational attraction at long distances.

  19. Evidence for Nonlocal Electrodynamics in Planar Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Boris, A. A.; Rydh, A.; Golod, T.; Motzkau, H.; Klushin, A. M.; Krasnov, V. M.

    2013-09-01

    We study the temperature dependence of the critical current modulation Ic(H) for two types of planar Josephson junctions: a low-Tc Nb/CuNi/Nb and a high-Tc YBa2Cu3O7-δ bicrystal grain-boundary junction. At low T both junctions exhibit a conventional behavior, described by the local sine-Gordon equation. However, at elevated T the behavior becomes qualitatively different: the Ic(H) modulation field ΔH becomes almost T independent and neither ΔH nor the critical field for the penetration of Josephson vortices vanish at Tc. Such an unusual behavior is in good agreement with theoretical predictions for junctions with nonlocal electrodynamics. We extract absolute values of the London penetration depth λ from our data and show that a crossover from local to nonlocal electrodynamics occurs with increasing T when λ(T) becomes larger than the electrode thickness.

  20. Explaination of nonlocal granular fluidity in terms of microscopic fluctuations

    NASA Astrophysics Data System (ADS)

    Zhang, Qiong; Kamrin, Ken

    A recently proposed granular constitutive law has shown capability to predict nonlocal granular rheology using a variable denoted ``granular fluidity''. This work is aimed at finding the microscopic physical meaning of fluidity in terms of fluctuations such as fluctuation of normalized shear stress and fluctuation of velocity. We try to predict the fluidity as a function of the fluctuation of normalized shear stress, and also test Eyring equation and kinetic theory based on the theoretical prediction proposed in other work. We find a consistent definition for the fluidity to be proportional to the product of the velocity fluctuations and some function of packing fraction divided by the average diameter of the grains. This definition shows predictive ability in multiple geometries for which flow behavior is nonlocal. It is notable that the fluidity is well-defined as a function of kinematic state variables, as one would hope for a quantity of this nature.

  1. Beam envelope calculations in general linear coupled lattices

    NASA Astrophysics Data System (ADS)

    Chung, Moses; Qin, Hong; Groening, Lars; Davidson, Ronald C.; Xiao, Chen

    2015-01-01

    The envelope equations and Twiss parameters (β and α) provide important bases for uncoupled linear beam dynamics. For sophisticated beam manipulations, however, coupling elements between two transverse planes are intentionally introduced. The recently developed generalized Courant-Snyder theory offers an effective way of describing the linear beam dynamics in such coupled systems with a remarkably similar mathematical structure to the original Courant-Snyder theory. In this work, we present numerical solutions to the symmetrized matrix envelope equation for β which removes the gauge freedom in the matrix envelope equation for w. Furthermore, we construct the transfer and beam matrices in terms of the generalized Twiss parameters, which enables calculation of the beam envelopes in arbitrary linear coupled systems.

  2. Beam envelope calculations in general linear coupled lattices

    SciTech Connect

    Chung, Moses; Qin, Hong; Groening, Lars; Xiao, Chen; Davidson, Ronald C.

    2015-01-15

    The envelope equations and Twiss parameters (β and α) provide important bases for uncoupled linear beam dynamics. For sophisticated beam manipulations, however, coupling elements between two transverse planes are intentionally introduced. The recently developed generalized Courant-Snyder theory offers an effective way of describing the linear beam dynamics in such coupled systems with a remarkably similar mathematical structure to the original Courant-Snyder theory. In this work, we present numerical solutions to the symmetrized matrix envelope equation for β which removes the gauge freedom in the matrix envelope equation for w. Furthermore, we construct the transfer and beam matrices in terms of the generalized Twiss parameters, which enables calculation of the beam envelopes in arbitrary linear coupled systems.

  3. Nonlocality in quantum theory understood in terms of Einstein's nonlinear field approach

    NASA Astrophysics Data System (ADS)

    Bohm, D.; Hiley, B. J.

    1981-08-01

    We discuss Einstein's ideas on the need for a theory that is both objective and local and also his suggestion for realizing such a theory through nonlinear field equations. We go on to analyze the nonlocality implied by the quantum theory, especially in terms of the experiment of Einstein, Podolsky, and Rosen. We then suggest an objective local field model along Einstein's lines, which might explain quantum nonlocality as a coordination of the properties of pulse-like solutions of the nonlinear equations that would represent particles. Finally, we discuss the implications of our model for Bell's inequality.

  4. Cosmological perturbations in SFT inspired non-local scalar field models

    NASA Astrophysics Data System (ADS)

    Koshelev, Alexey S.; Vernov, Sergey Yu.

    2012-10-01

    We study cosmological perturbations in models with a single non-local scalar field originating from the string field theory description of the rolling tachyon dynamics. We construct the equation for the energy density perturbations of the non-local scalar field and explicitly prove that for the free field it is identical to a system of local cosmological perturbation equations in a particular model with multiple (maybe infinitely many) local free scalar fields. We also show that vector and tensor perturbations are absent in this set-up.

  5. Circumplanetary disc or circumplanetary envelope?

    NASA Astrophysics Data System (ADS)

    Szulágyi, J.; Masset, F.; Lega, E.; Crida, A.; Morbidelli, A.; Guillot, T.

    2016-08-01

    We present three-dimensional simulations with nested meshes of the dynamics of the gas around a Jupiter mass planet with the JUPITER and FARGOCA codes. We implemented a radiative transfer module into the JUPITER code to account for realistic heating and cooling of the gas. We focus on the circumplanetary gas flow, determining its characteristics at very high resolution (80 per cent of Jupiter's diameter). In our nominal simulation where the temperature evolves freely by the radiative module and reaches 13000 K at the planet, a circumplanetary envelope was formed filling the entire Roche lobe. Because of our equation of state is simplified and probably overestimates the temperature, we also performed simulations with limited maximal temperatures in the planet region (1000, 1500, and 2000 K). In these fixed temperature cases circumplanetary discs (CPDs) were formed. This suggests that the capability to form a CPD is not simply linked to the mass of the planet and its ability to open a gap. Instead, the gas temperature at the planet's location, which depends on its accretion history, plays also fundamental role. The CPDs in the simulations are hot and cooling very slowly, they have very steep temperature and density profiles, and are strongly sub-Keplerian. Moreover, the CPDs are fed by a strong vertical influx, which shocks on the CPD surfaces creating a hot and luminous shock-front. In contrast, the pressure supported circumplanetary envelope is characterized by internal convection and almost stalled rotation.

  6. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    SciTech Connect

    HERTING DL

    2008-03-19

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions.

  7. Unified criteria for multipartite quantum nonlocality

    SciTech Connect

    Cavalcanti, E. G.; He, Q. Y.; Reid, M. D.; Wiseman, H. M.

    2011-09-15

    Wiseman and co-workers [H. M. Wiseman, S. J. Jones, and A. C. Doherty, Phys. Rev. Lett. 98, 140402, (2007)] proposed a distinction among the nonlocality classes of Bell's nonlocality, Einstein-Podolsky-Rosen (EPR) paradox or steering, and entanglement based on whether or not an overseer trusts each party in a bipartite scenario where they are asked to demonstrate entanglement. Here we extend that concept to the multipartite case and derive inequalities that progressively test for those classes of nonlocality, with different thresholds for each level. This framework includes the three classes of nonlocality above in special cases and introduces a family of others.

  8. Robustness of multiparty nonlocality to local decoherence

    NASA Astrophysics Data System (ADS)

    Jang, Sung Soon; Cheong, Yong Wook; Kim, Jaewan; Lee, Hai-Woong

    2006-12-01

    We investigate the robustness of multiparty nonlocality under local decoherence, acting independently and equally on each subsystem. To be specific, we consider an N -qubit Greenberger-Horne-Zeilinger (GHZ) state under a depolarization, dephasing, or dissipation channel, and examine nonlocality by testing violation of the Mermin-Klyshko inequality, which is one of Bell’s inequalities for multiqubit systems. The results show that the robustness of nonlocality increases with the number of qubits, and that the nonlocality of an N -qubit GHZ state with even N is extremely persistent against dephasing.

  9. Targeting Nuclear Envelope Repair.

    PubMed

    2016-06-01

    Migrating cancer cells undergo repeated rupture of the protective nuclear envelope as they squeeze through small spaces in the surrounding tissue, compromising genomic integrity. Inhibiting both general DNA repair and the mechanism that seals these tears may enhance cell death and curb metastasis. PMID:27130435

  10. Jacketed lamp bulb envelope

    DOEpatents

    MacLennan, Donald A.; Turner, Brian P.; Gitsevich, Aleksandr; Bass, Gary K.; Dolan, James T.; Kipling, Kent; Kirkpatrick, Douglas A.; Leng, Yongzhang; Levin, Izrail; Roy, Robert J.; Shanks, Bruce; Smith, Malcolm; Trimble, William C.; Tsai, Peter

    2001-01-01

    A jacketed lamp bulb envelope includes a ceramic cup having an open end and a partially closed end, the partially closed end defining an aperture, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material at least partially covering a portion of the bulb not abutting the aperture. The reflective ceramic material may substantially fill an interior volume of the ceramic cup not occupied by the bulb. The ceramic cup may include a structural feature for aiding in alignment of the jacketed lamp bulb envelope in a lamp. The ceramic cup may include an external flange about a periphery thereof. One example of a jacketed lamp bulb envelope includes a ceramic cup having an open end and a closed end, a ceramic washer covering the open end of the ceramic cup, the washer defining an aperture therethrough, a lamp bulb positioned inside the ceramic cup abutting the aperture, and a reflective ceramic material filling an interior volume of the ceramic cup not occupied by the bulb. A method of packing a jacketed lamp bulb envelope of the type comprising a ceramic cup with a lamp bulb disposed therein includes the steps of filling the ceramic cup with a flowable slurry of reflective material, and applying centrifugal force to the cup to pack the reflective material therein.

  11. Nonlocal plate model for free vibrations of single-layered graphene sheets

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Sahmani, S.; Arash, B.

    2010-11-01

    Vibration analysis of single-layered graphene sheets (SLGSs) is investigated using nonlocal continuum plate model. To this end, Eringens's nonlocal elasticity equations are incorporated into the classical Mindlin plate theory for vibrations of rectangular nanoplates. In contrast to the classical model, the nonlocal model developed in this study has the capability to evaluate the natural frequencies of the graphene sheets with considering the size-effects on the vibrational characteristics of them. Solutions for frequencies of the free vibration of simply-supported and clamped SLGSs are computed using generalized differential quadrature (GDQ) method. Then, molecular dynamics (MD) simulations for the free vibration of various SLGSs with different values of side length and chirality are employed, the results of which are matched with the nonlocal model ones to derive the appropriate values of the nonlocal parameter relevant to each boundary condition. It is found that the value of the nonlocal parameter is independent of the magnitude of the geometrical variables of the system.

  12. Postbuckling behaviors of nanorods including the effects of nonlocal elasticity theory and surface stress

    SciTech Connect

    Thongyothee, Chawis Chucheepsakul, Somchai

    2013-12-28

    This paper is concerned with postbuckling behaviors of nanorods subjected to an end concentrated load. One end of the nanorod is clamped while the other end is fixed to a support that can slide in the slot. The governing equation is developed from static equilibrium and geometrical conditions by using the exact curvature corresponding to the elastica theory. The nonlocal elasticity, the effect of surface stress, and their combined effects are taken into account in Euler–Bernoulli beam theory. Differential equations in this problem can be solved numerically by using the shooting-optimization technique for the postbuckling loads and the buckled configurations. The results show that nanorods with the nonlocal elasticity effect undergo increasingly large deformation while the effect of surface stress in combination with nonlocal elasticity decreases the deflection of nanorods under the same postbuckling load.

  13. More nonlocality with less entanglement

    SciTech Connect

    Vidick, Thomas; Wehner, Stephanie

    2011-05-15

    Recent numerical investigations [K. Pal and T. Vertesi, Phys. Rev. A 82, 022116 (2010)] suggest that the I3322 inequality, arguably the simplest extremal Bell inequality after the CHSH inequality, has a very rich structure in terms of the entangled states and measurements that maximally violate it. Here we show that for this inequality the maximally entangled state of any dimension achieves the same violation than just a single EPR pair. In contrast, stronger violations can be achieved using higher dimensional states which are less entangled. This shows that the maximally entangled state is not the most nonlocal resource, even when one restricts attention to the most simple extremal Bell inequalities.

  14. STS-8 postal Stamp envelope

    NASA Technical Reports Server (NTRS)

    1983-01-01

    STS-8 postal Stamp envelope with Challenger insignia, USA eagle stamp, 25th NASA anniversary stamp. The envelope is stamped with various postmarks, one saying Kennedy Space Center, Fl., another saying 'Returned to earth, Edwards AFB, CA'.

  15. Nonlocal Closures for Plasma Fluid Simulations

    NASA Astrophysics Data System (ADS)

    Held, Eric

    2003-10-01

    Theoretical tools applied to lab and astrophysical plasmas tend toward two extremes: kinetic models rife with physics but operating for short times and fluid models employing simplified closure relations but operating for long times. Until computers are fast enough to calculate kinetic physics over resistive times, efforts to extend plasma fluid models to handle a wider range of physics are critical. In this work, we generalize the program of fluid closure to capture kinetic effects in nonlocal, integral forms for higher-order fluid moments. These closures embody collisional, particle-trapping and Landau physics by integrating the fluid drives and closure moments along characteristics of the distribution function, F. The inversion of an operator that includes these physical effects begins with an expansion in eigenfunctions of the collision operator. Next, the characteristics of F are identified by diagonalizing the resultant system of hyperbolic equations. Integrating and taking the closure moments of F results in coupled Volterra equations involving the fluid drives and closures. It is shown that the collisional and nearly collisionless limits of these integral equations match onto previous expressions. In addition to significantly advancing the realism of previous fluid closures, integration along comparatively few ( ˜ 100)characteristics represents a significant reduction in work compared to kinetic treatments that follow millions of particles. These characteristics uncover the essential velocity-space dependence of F and hence render this closure scheme suitable for simulation of long time scale behavior. As a specific example, we conclude this talk by discussing the incorporation of these closures in plasma fluid simulations of neoclassical tearing modes in ITER-relevant discharges.

  16. Conformal symmetry and nonlinear extensions of nonlocal gravity

    NASA Astrophysics Data System (ADS)

    Cusin, Giulia; Foffa, Stefano; Maggiore, Michele; Mancarella, Michele

    2016-04-01

    We study two nonlinear extensions of the nonlocal R □-2R gravity theory. We extend this theory in two different ways suggested by conformal symmetry, either replacing □-2 with (-□+R /6 )-2, which is the operator that enters the action for a conformally-coupled scalar field, or replacing □-2 with the inverse of the Paneitz operator, which is a four-derivative operator that enters in the effective action induced by the conformal anomaly. We show that the former modification gives an interesting and viable cosmological model, with a dark energy equation of state today wDE≃-1.01 , which very closely mimics Λ CDM and evolves asymptotically into a de Sitter solution. The model based on the Paneitz operator seems instead excluded by the comparison with observations. We also review some issues about the causality of nonlocal theories, and we point out that these nonlocal models can be modified so to nicely interpolate between Starobinski inflation in the primordial universe and accelerated expansion in the recent epoch.

  17. Nonlocal Heat Transport by Longitudinal/Transverse EM Waves in Magnetically Confined Plasmas and Modelling of the Observed Nonlocal Phenomena in a Tokamak

    NASA Astrophysics Data System (ADS)

    Kukushkin, A. B.

    1996-11-01

    The nonlocal transport approach is formulated, based on anomalous cross-field energy transport (ACFET) by the longitudinal/tranverse EM waves of the mean free path of the order and much larger than plasma characteristic size and, correspondingly, on integral equation in space variables. Self-consistency of this approach is shown in interpreting those observed phenomena of nonlocality whose interpretation in "local", diffusion-like approaches gives instant jumps of thermal diffusivities in a large part of plasma volume. The modelling is carried out of the initial stage of recently observed phenomena of fast nonlocal energy transport: (i) net inward flux of energy during off-axis heating (vs. ECRH experiments on D-III-D); (ii) prompt rise of temperature in the core in "cold pulse" experiments (fast cooling of the periphery) on TEXT and TFTR; (iii) fast "volumetric" response of energy transport to plasma edge behavior during L-H transitions (in JET and JT-60U). The results suggest (a) universal and transparent physical explanation of the mechanism of nonlocal inward energy flux, which is lost in diffusion-like approaches, and (b) necessity to append existing numerical codes with nonlocal transport term, an integral in space variables.

  18. Hyperbolic metamaterial lens with hydrodynamic nonlocal response.

    PubMed

    Yan, Wei; Mortensen, N Asger; Wubs, Martijn

    2013-06-17

    We investigate the effects of hydrodynamic nonlocal response in hyperbolic metamaterials (HMMs), focusing on the experimentally realizable parameter regime where unit cells are much smaller than an optical wavelength but much larger than the wavelengths of the longitudinal pressure waves of the free-electron plasma in the metal constituents. We derive the nonlocal corrections to the effective material parameters analytically, and illustrate the noticeable nonlocal effects on the dispersion curves numerically. As an application, we find that the focusing characteristics of a HMM lens in the local-response approximation and in the hydrodynamic Drude model can differ considerably. In particular, the optimal frequency for imaging in the nonlocal theory is blueshifted with respect to that in the local theory. Thus, to detect whether nonlocal response is at work in a hyperbolic metamaterial, we propose to measure the near-field distribution of a hyperbolic metamaterial lens. PMID:23787690

  19. Virial Theorem in Nonlocal Newtonian Gravity

    NASA Astrophysics Data System (ADS)

    Mashhoon, Bahram

    2016-05-01

    Nonlocal gravity is the recent classical nonlocal generalization of Einstein's theory of gravitation in which the past history of the gravitational field is taken into account. In this theory, nonlocality appears to simulate dark matter. The virial theorem for the Newtonian regime of nonlocal gravity theory is derived and its consequences for "isolated" astronomical systems in virial equilibrium at the present epoch are investigated. In particular, for a sufficiently isolated nearby galaxy in virial equilibrium, the galaxy's baryonic diameter---namely, the diameter of the smallest sphere that completely surrounds the baryonic system at the present time---is predicted to be larger than the effective dark matter fraction times a universal length that is the basic nonlocality length scale of about 3 kpc.

  20. The effect of calibrated nonlocal constant on the modal parameters and stability of axially compressed CNTs

    NASA Astrophysics Data System (ADS)

    Fathi, Reza; Lotfan, Saeed

    2016-05-01

    Nowadays investigating the vibration behavior of carbon nanotubes (CNTs) has drawn considerable attention due to the superior mechanical properties of the CNTs. One of the powerful theoretical methods to study the vibration behavior of CNTs is implementing the nonlocal theory. Most of studies on the vibration behavior of CNTs have assumed a fixed value for small scale parameter for all vibration modes, however, this value is mode-dependent. Therefore, in this paper, the small scale parameter is calibrated for a single-walled carbon nanotube (SWCNT) with respect to each vibration mode. For this propose, the governing equation of motion based on the nonlocal beam theory is extracted by applying the Hamilton's principle. Then, by using the power series method, an eigenvalue problem is defined to derive the calibrated value of small scale constant and nonlocal mode shapes of the CNT. By using the expansion theory, the equation of motion is discretized, and the effect of nonlocality on the modal parameters and stability of the CNT under compressive force is investigated. Finally, the possibility of estimating nonlocal parameter based on simulated frequency domain response of the system by using modal analysis methods is studied. The results show that the calibration of small scale constant is important and the critical axial force is highly sensitive to this value.

  1. Stability and bifurcations in a nonlocal delayed reaction-diffusion population model

    NASA Astrophysics Data System (ADS)

    Chen, Shanshan; Yu, Jianshe

    2016-01-01

    A nonlocal delayed reaction-diffusion equation with Dirichlet boundary condition is considered in this paper. It is shown that a positive spatially nonhomogeneous equilibrium bifurcates from the trivial equilibrium. The stability/instability of the bifurcated positive equilibrium and associated Hopf bifurcation are investigated, providing us with a complete picture of the dynamics.

  2. Nonlocal contour dynamics model for chemical front motion

    NASA Astrophysics Data System (ADS)

    Petrich, Dean M.; Goldstein, Raymond E.

    1994-02-01

    Pattern formation exhibited by a two-dimensional reaction-diffusion system in the fast inhibitor limit is considered for the point of view of interface motion. A dissipative nonlocal equation of motion for the boundary between high and low concentrations of the slow species is derived heuristically. Under these dynamics, a compact domain of high concentration may develop into a space-filling labyrinthine structure in which nearby fronts repel. Similar patterns have been observed recently by Lee, McCormick, Ouyang, and Swinney in a reacting chemical system.

  3. Diagnostics of nonlocal plasmas: advanced techniques

    NASA Astrophysics Data System (ADS)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  4. A nonlocal Fourier's law and its application to the heat conduction of one-dimensional and two-dimensional thermal lattices

    NASA Astrophysics Data System (ADS)

    Challamel, Noël; Grazide, Cécile; Picandet, Vincent; Perrot, Arnaud; Zhang, Yingyan

    2016-06-01

    This study focuses on heat conduction in unidimensional lattices also known as microstructured rods. The lattice thermal properties can be representative of concentrated thermal interface phases in one-dimensional segmented rods. The exact solution of the linear time-dependent spatial difference equation associated with the lattice problem is presented for some given initial and boundary conditions. This exact solution is compared to the quasicontinuum approximation built by continualization of the lattice equations. A rational-based asymptotic expansion of the pseudo-differential problem leads to an equivalent nonlocal-type Fourier's law. The differential nonlocal Fourier's law is analysed with respect to thermodynamic models available in the literature, such as the Guyer-Krumhansl-type equation. The length scale of the nonlocal heat law is calibrated with respect to the lattice spacing. An error analysis is conducted for quantifying the efficiency of the nonlocal model to capture the lattice evolution problem, as compared to the local model. The propagation of error with the nonlocal model is much slower than that in its local counterpart. A two-dimensional thermal lattice is also considered and approximated by a two-dimensional nonlocal heat problem. It is shown that nonlocal and continualized heat equations both approximate efficiently the two-dimensional thermal lattice response. These extended continuous heat models are shown to be good candidates for approximating the heat transfer behaviour of microstructured rods or membranes.

  5. Can EPR non-locality be geometrical?

    SciTech Connect

    Ne`eman, Y. |; Botero, A.

    1995-10-01

    The presence in Quantum Mechanics of non-local correlations is one of the two fundamentally non-intuitive features of that theory. The non-local correlations themselves fall into two classes: EPR and Geometrical. The non-local characteristics of the geometrical type are well-understood and are not suspected of possibly generating acausal features, such as faster-than-light propagation of information. This has especially become true since the emergence of a geometrical treatment for the relevant gauge theories, i.e. Fiber Bundle geometry, in which the quantum non-localities are seen to correspond to pure homotopy considerations. This aspect is reviewed in section 2. Contrary-wise, from its very conception, the EPR situation was felt to be paradoxical. It has been suggested that the non-local features of EPR might also derive from geometrical considerations, like all other non-local characteristics of QM. In[7], one of the authors was able to point out several plausibility arguments for this thesis, emphasizing in particular similarities between the non-local correlations provided by any gauge field theory and those required by the preservation of the quantum numbers of the original EPR state-vector, throughout its spatially-extended mode. The derivation was, however, somewhat incomplete, especially because of the apparent difference between, on the one hand, the closed spatial loops arising in the analysis of the geometrical non-localities, from Aharonov-Bohm and Berry phases to magnetic monopoles and instantons, and on the other hand, in the EPR case, the open line drawn by the positions of the two moving decay products of the disintegrating particle. In what follows, the authors endeavor to remove this obstacle and show that as in all other QM non-localities, EPR is somehow related to closed loops, almost involving homotopy considerations. They develop this view in section 3.

  6. Experimental test of nonlocal causality.

    PubMed

    Ringbauer, Martin; Giarmatzi, Christina; Chaves, Rafael; Costa, Fabio; White, Andrew G; Fedrizzi, Alessandro

    2016-08-01

    Explaining observations in terms of causes and effects is central to empirical science. However, correlations between entangled quantum particles seem to defy such an explanation. This implies that some of the fundamental assumptions of causal explanations have to give way. We consider a relaxation of one of these assumptions, Bell's local causality, by allowing outcome dependence: a direct causal influence between the outcomes of measurements of remote parties. We use interventional data from a photonic experiment to bound the strength of this causal influence in a two-party Bell scenario, and observational data from a Bell-type inequality test for the considered models. Our results demonstrate the incompatibility of quantum mechanics with a broad class of nonlocal causal models, which includes Bell-local models as a special case. Recovering a classical causal picture of quantum correlations thus requires an even more radical modification of our classical notion of cause and effect. PMID:27532045

  7. Experimental test of nonlocal causality

    PubMed Central

    Ringbauer, Martin; Giarmatzi, Christina; Chaves, Rafael; Costa, Fabio; White, Andrew G.; Fedrizzi, Alessandro

    2016-01-01

    Explaining observations in terms of causes and effects is central to empirical science. However, correlations between entangled quantum particles seem to defy such an explanation. This implies that some of the fundamental assumptions of causal explanations have to give way. We consider a relaxation of one of these assumptions, Bell’s local causality, by allowing outcome dependence: a direct causal influence between the outcomes of measurements of remote parties. We use interventional data from a photonic experiment to bound the strength of this causal influence in a two-party Bell scenario, and observational data from a Bell-type inequality test for the considered models. Our results demonstrate the incompatibility of quantum mechanics with a broad class of nonlocal causal models, which includes Bell-local models as a special case. Recovering a classical causal picture of quantum correlations thus requires an even more radical modification of our classical notion of cause and effect. PMID:27532045

  8. Nonlocality of the Aharonov-Bohm effect

    NASA Astrophysics Data System (ADS)

    Aharonov, Yakir; Cohen, Eliahu; Rohrlich, Daniel

    2016-04-01

    Although the Aharonov-Bohm and related effects are familiar in solid-state and high-energy physics, the nonlocality of these effects has been questioned. Here we show that the Aharonov-Bohm effect has two very different aspects. One aspect is instantaneous and nonlocal; the other aspect, which depends on entanglement, unfolds continuously over time. While local, gauge-invariant variables may occasionally suffice for explaining the continuous aspect, we argue that they cannot explain the instantaneous aspect. Thus the Aharonov-Bohm effect is, in general, nonlocal.

  9. All entangled quantum states are nonlocal.

    PubMed

    Buscemi, Francesco

    2012-05-18

    Departing from the usual paradigm of local operations and classical communication adopted in entanglement theory, we study here the interconversion of quantum states by means of local operations and shared randomness. A set of necessary and sufficient conditions for the existence of such a transformation between two given quantum states is given in terms of the payoff they yield in a suitable class of nonlocal games. It is shown that, as a consequence of our result, such a class of nonlocal games is able to witness quantum entanglement, however weak, and reveal nonlocality in any entangled quantum state. An example illustrating this fact is provided. PMID:23003127

  10. Model scattering envelopes of young stellar objects. II - Infalling envelopes

    NASA Technical Reports Server (NTRS)

    Whitney, Barbara A.; Hartmann, Lee

    1993-01-01

    We present scattered light images for models of young stellar objects surrounded by dusty envelopes. The envelopes are assumed to have finite angular momentum and are falling in steady flow onto a disk. The model envelopes include holes, such as might be created by energetic bipolar flows. We calculate images using the Monte Carlo method to follow the light scattered in the dusty envelope and circumstellar disk, assuming that the photons originate from the central source. Adopting typical interstellar medium dust opacities and expected mass infall rates for protostars of about 10 exp -6 solar mass/yr, we find that detectable amounts of optical radiation can escape from envelopes falling into a disk as small as about 10-100 AU, depending upon the viewing angle and the size of the bipolar flow cavity. We suggest that the extended optical and near-IR light observed around several young stars is scattered by dusty infalling envelopes rather than disks.

  11. Non-local ocean mixing model and a new plume model for deep convection

    NASA Astrophysics Data System (ADS)

    Canuto, V. M.; Cheng, Y.; Howard, A. M.

    Turbulent fluxes can be represented by a diffusivity tensor, the symmetric part of which describes " turbulent diffusion" while the anti-symmetric part describes " advection". Diffusion is a local process in the sense that it depends only on the local gradients of the mean fields while advection is non-local for it is represented by an integral over all length scales (all eddies) that can "fit" from say the bottom of the physical domain to the z where the fluxes are computed. In the ocean, there are two main regimes where non-local transport is important. One regime is where storms release a sudden burst of mechanical energy to the ocean surface that is then transported downward by energetic eddies that deepen the mixed layer. Even relatively simple non-local models yield results considerably more realistic than those of local models. The second regime is deep convection (DC) caused by loss of surface buoyancy, the description of which is required for a reliable assessment of water masses formation. At present, there is no reliable model for either of these non-local regimes individually or much less a formalism capable of accounting for both regimes simultaneously. The goal of this paper is to present a formalism that provides the expressions for the non-local fluxes for momentum, heat and salinity encompassing both cases. Since the resulting number of dynamic equations involves is however large, we work out two sub-models, one when only shear must be treated non-locally (e.g., when storms release mechanical energy) and one when only buoyancy is to be treated non-locally (the DC case). We employ the Reynolds Stress formalism in which non-locality is represented by the third-order moments which in turn depend on the fourth-order moments for which we employ a new model that has been tested against LES data, aircraft data and a full PBL simulation. For the DC case, we rewrite the non-local model in terms of Plumes since thus far the only non-local model used to treat

  12. Refrigerated cryogenic envelope

    DOEpatents

    Loudon, John D.

    1976-11-16

    An elongated cryogenic envelope including an outer tube and an inner tube coaxially spaced within said inner tube so that the space therebetween forms a vacuum chamber for holding a vacuum. The inner and outer tubes are provided with means for expanding or contracting during thermal changes. A shield is located in the vacuum chamber intermediate the inner and outer tubes; and, a refrigeration tube for directing refrigeration to the shield is coiled about at least a portion of the inner tube within the vacuum chamber to permit the refrigeration tube to expand or contract along its length during thermal changes within said vacuum chamber.

  13. Discontinuous envelope function in semiconductor heterostructures

    NASA Astrophysics Data System (ADS)

    Drouhin, Henri-Jean; Bottegoni, Federico; Nguyen, T. L. Hoai; Wegrowe, Jean-Eric; Fishman, Guy

    2013-09-01

    Based on a proper definition of the current operators for non-quadratic Hamiltonians, we derive the expression for the transport current which involves the derivative of the imaginary part of the free-electron current, highlighting peculiarities of the extra terms. The expression of the probability current, when Spin-Orbit Interaction (SOI) is taken into account, requires a reformulation of the boudary conditions. This is especially important for tunnel heterojunctions made of non-centrosymmetric semiconductors. Therefore, we consider a model case: tunneling of conduction electrons through a [110]-oriented GaAs barrier. The new boundary conditions are reduced to two set of equations: the first one expresses the discontinuity of the envelope function at the interface while the other one expresses the discontinuity of the derivative of the envelope function.

  14. Evaluation of nonlocal parameter in the vibrations of single-walled carbon nanotubes with initial strain

    NASA Astrophysics Data System (ADS)

    Arash, B.; Ansari, R.

    2010-06-01

    Based upon a nonlocal shell model accounting for the small-scale effects, the vibration characteristics of single-walled carbon nanotubes (SWCNTs) with different boundary conditions subjected to initial strain are studied in this paper. The set of governing equations of motion is numerically solved by a method that emerged from incorporating the radial point interpolation approximation within the framework of the generalized differential quadrature method. The effectiveness of the present nonlocal shell model is assessed by the molecular dynamics simulations as a benchmark of good accuracy. Accordingly, nonlocal parameters for clamped and cantilever SWCNTs with thicknesses of 0.066 and 0.34 nm are proposed due to the uncertainty that exists in defining nanotube wall thickness. The simulation results show that the resonant frequencies of SWCNTs are very sensitive to the initial strain, although small.

  15. Nonlocal transient thermal analysis of a single-layered graphene sheet embedded in viscoelastic medium

    NASA Astrophysics Data System (ADS)

    Zenkour, Ashraf M.

    2016-05-01

    The transient thermal analysis of a single-layered graphene sheet (SLGS) embedded in viscoelastic medium is presented by using the nonlocal elasticity theory. The elastic medium, which characterized by the linear Winkler's modulus and Pasternak's (shear) foundation modulus, is changed to a viscoelastic one by including the viscous damping term. The governing dynamical equation is obtained and solved for simply-supported SLGSs. Firstly; the effect of the nonlocal parameter is discussed carefully for the vibration and bending problems. Secondly, the effects of other parameter like aspect ratio, thickness-to-length ratio, Winkler-Pasternak's foundation, viscous damping coefficient on bending field quantities of the SLGSs are investigated in detail. The present results are compared with the corresponding available in the literature. Additional results for thermal local and nonlocal deflections and stresses are presented to investigate the thermal visco-Pasternak's parameters for future comparisons.

  16. The Gardner category and nonlocal conservation laws for N=1 Super KdV

    SciTech Connect

    Andrea, S.; Restuccia, A.; Sotomayor, A.

    2005-10-01

    The nonlocal conserved quantities of the N=1 Super KdV are obtained using a Gardner map. A fermionic substitution semigroup and the resulting Gardner category are defined and several propositions concerning their algebraic structure are obtained. This algebraic framework makes it possible to define general transformations between different nonlinear SUSY differential equations. A SUSY ring extension is then introduced to deal with the nonlocal conserved quantities of SKdV. The algebraic version of the nonlocal conserved quantities is solved in terms of the exponential function applied to the D{sup -1} of the local conserved quantities of SKdV. Finally the same formulas are shown to work for rapidly decreasing superfields.

  17. Nonlinear vibration behavior of a rotating nanobeam under thermal stress using Eringen's nonlocal elasticity and DQM

    NASA Astrophysics Data System (ADS)

    Shafiei, Navvab; Kazemi, Mohammad; Ghadiri, Majid

    2016-08-01

    This study is concerned with the small-scale effect on the nonlinear flapwise bending vibration of rotating cantilever and propped cantilever nanobeams. Euler-Bernoulli beam theory is used to model the nanobeam with nonlinearity. Nonlinear strain-displacement relations are employed to account for geometric nonlinearity of the system. The axial forces are modeled as the true spatial and thermal variations due to the rotation. Hamilton's principle is used to derive the nonlinear governing equation and nonlocal nonlinear boundary conditions based on Eringen's nonlocal elasticity theory. Finally, the differential quadrature method is used in conjunction with the direct iterative method to derive the nonlinear vibration frequencies of the nanobeam. The effects of the angular velocity, nonlocal small-scale parameter, temperature change and nonlinear amplitude on nonlinear vibration of the rotary nanobeam are discussed. The results of this work can be used in nanosensors, nanomotors, nanoturbines and NEMS applications.

  18. Frequency analysis of curved nano-sandwich structure based on a nonlocal model

    NASA Astrophysics Data System (ADS)

    Rahmani, O.; Hosseini, S. A. H.; Hayati, H.

    2016-04-01

    In this paper, we study the vibration of curved nano-sandwich (CNS) with considering the influence of core shear based on the Eringen nonlocal theory. The equation of motion is derived and exact solution for the natural frequencies of CNS is presented. The proposed nonlocal model includes a material length scale parameter that can capture the size effect in CNS beam. The effects of important parameters, such as the thickness to length ratio, nonlocal parameter and mode number on the frequencies of CNS are investigated. The result of our research shows that as the opening angle increases, the amount of natural frequencies decrease. We have additionally validate, our results against previous research works which showed good agreement.

  19. A unified formulation for dynamic analysis of nonlocal heterogeneous nanobeams in hygro-thermal environment

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Farzad; Barati, Mohammad Reza

    2016-09-01

    In this article, combined effect of moisture and temperature on free vibration characteristics of functionally graded (FG) nanobeams resting on elastic foundation is investigated by developing various refined beam theories which capture shear deformation influences needless of any shear correction factor. The material properties of FG nanobeam are temperature dependent and change gradually along the thickness through the power-law model. Size-dependent description of the nanobeam is performed applying nonlocal elasticity theory of Eringen. Nonlocal governing equations of embedded FG nanobeam in hygro-thermal environment obtained from Hamilton's principle are solved analytically. To verify the validity of the developed theories, the results of the present work are compared with those available in the literature. The effects of various hygro-thermal loadings, elastic foundation, gradient index, nonlocal parameter, and slenderness ratio on the vibrational behavior of FG nanobeams modeled via various beam theories are explored.

  20. Nonlocal ordinary magnetoresistance in indium arsenide

    NASA Astrophysics Data System (ADS)

    Liu, Pan.; Yuan, Zhonghui.; Wu, Hao.; Ali, S. S.; Wan, Caihua.; Ban, Shiliang.

    2015-07-01

    Deflection of carriers by Lorentz force results in an ordinary magnetoresistance (OMR) of (μB)2 at low field. Here we demonstrate that the OMR in high mobility semiconductor InAs could be enhanced by measurement geometry where two probes of voltmeter were both placed on one outer side of two probes of current source. The nonlocal OMR was 3.6 times as large as the local one, reaching 1.8×104% at 5 T. The slope of the linear field dependence of the nonlocal OMR was improved from 12.6 T-1 to 45.3 T-1. The improvement was ascribed to polarity-conserved charges accumulating on boundaries in nonlocal region due to Hall effect. This InAs device with nonlocal geometry could be competitive in B-sensors due to its high OMR ratio, linear field dependence and simple structure.

  1. Nonlocal transport of passive scalars in turbulent penetrative convection

    PubMed

    Miesch; Brandenburg; Zweibel

    2000-01-01

    We present a Green's function approach for quantifying the transport of a passive scalar (tracer) field in three-dimensional simulations of turbulent convection. Nonlocal, nondiffusive behavior is described by a transilient matrix (the discretized Green's function), whose elements contain the fractional tracer concentrations moving from one subvolume to another as a function of time. The approach was originally developed for and applied to geophysical flows, but here we extend the formalism and apply it in an astrophysical context to three-dimensional simulations of turbulent compressible convection with overshoot into convectively stable bounding regions. We introduce a novel technique to compute this matrix in a single simulation by advecting labeled particles rather than solving the passive scalar equation for a large number of different initial conditions. The transilient matrices thus computed are used as a diagnostic tool to quantitatively describe nonlocal transport via matrix moments and transport coefficients in a generalized, multiorder diffusion equation. Results indicate that transport in both the vertical and horizontal directions is strongly influenced by the presence of coherent velocity structures, generally resembling ballistic advection more than diffusion. The transport of a small fraction of tracer particles deep into the underlying stable region is reasonably efficient, a result which has possible implications for the problem of light-element depletion in late-type stars. PMID:11046285

  2. Nonlocal-integro-differential modeling of vibration of elastically supported nanorods

    NASA Astrophysics Data System (ADS)

    Kiani, Keivan

    2016-09-01

    In the previously established nonlocal continuum-based models, small characteristic length was commonly incorporated into the mass matrix and the driving force vector which is a bit in contradiction with our sense regarding these factors. Herein, a nonlocal-integro-differential version of the constitutive relations is employed for the bulk and the surface layer of the nanorod. By adopting Hamilton's principle, integro-partial differential equations of motion of elastically supported nanorods are established accounting for both nonlocality and surface energy effects. Then, these are solved by an efficient meshless methodology. For fixed-fixed and fixed-free nanorods, modal analysis of the problem is also performed and the explicit expressions of the mass and stiffness matrices are derived. For these special cases, the obtained results by the meshless technique are successfully verified with those of the modal solution. In the newly developed numerical model, the small-scale parameter is only incorporated into the stiffness matrix which gives us a more realistic sense about the nonlocality effect. Subsequently, the roles of the surface energy, small-scale parameter, elastic supports, and kernel function on natural frequencies of the nanostructure are discussed and explained. This work can be considered as a pivotal step towards a more reasonable nonlocal modeling of vibration of nanoscale structures.

  3. Nonlocality with ultracold atoms in a lattice

    NASA Astrophysics Data System (ADS)

    Pelisson, Sophie; Pezzè, Luca; Smerzi, Augusto

    2016-02-01

    We study the creation of nonlocal states with ultracold atoms trapped in an optical lattice. We show that these states violate Bell inequality by measuring one- and two-body correlations. Our scheme only requires beam-splitting operations and global phase shifts, and can be realized within the current technology, employing single-site addressing. This proposal paves the way to study multipartite nonlocality and entanglement in ultracold-atomic systems.

  4. Structure of quantum and broadcasting nonlocal correlations

    NASA Astrophysics Data System (ADS)

    Saha, Debashis; Pawłowski, Marcin

    2015-12-01

    The multipartite setting offers much more complexity of nonlocality than the bipartite one. We analyze the structure of tripartite nonlocal correlations by proposing inequalities satisfied by each of type bilocal, broadcasting, and quantum but violated by the other two. One of the inequalities satisfied by broadcasting correlations is generalized for multipartite systems. The study of its quantum mechanical violation reveals that Greenberger-Horne-Zeilinger-like states exhibit new, powerful correlations.

  5. Symmetric states: Their nonlocality and entanglement

    SciTech Connect

    Wang, Zizhu; Markham, Damian

    2014-12-04

    The nonlocality of permutation symmetric states of qubits is shown via an extension of the Hardy paradox and the extension of the associated inequality. This is achieved by using the Majorana representation, which is also a powerful tool in the study of entanglement properties of symmetric states. Through the Majorana representation, different nonlocal properties can be linked to different entanglement properties of a state, which is useful in determining the usefulness of different states in different quantum information processing tasks.

  6. Periodic envelopes of waves over non-uniform depth

    NASA Astrophysics Data System (ADS)

    Rajan, Girish K.; Bayram, Saziye; Henderson, Diane M.

    2016-04-01

    The envelope of narrow-banded, periodic, surface-gravity waves propagating in one dimension over water of finite, non-uniform depth may be modeled by the Djordjević and Redekopp ["On the development of packets of surface gravity waves moving over an uneven bottom," Z. Angew. Math. Phys. 29, 950-962 (1978)] equation (DRE). Here we find five approximate solutions of the DRE that are in the form of Jacobi-elliptic functions and discuss them within the framework of ocean swell. We find that in all cases, the maximum envelope-amplitude decreases/increases when the wave group propagates on water of decreasing/increasing depth. In the limit of the elliptic modulus approaching one, three of the solutions reduce to the envelope soliton solution. In the limit of the elliptic modulus approaching zero, two of the solutions reduce to an envelope-amplitude that is uniform in an appropriate reference frame.

  7. Nonlocalized receptivity of boundary layers to three-dimensional disturbances

    NASA Astrophysics Data System (ADS)

    Crouch, J. D.; Bertolotti, F. P.

    1992-01-01

    The nonlocalized receptivity of the Blasius boundary layer over a wavy surface is analyzed using two different approaches. First, a mode-interaction theory is employed to unveil basic mechanisms and to explore the interplay between different components of the disturbance field. The second approach is derived from the parabolized stability equations. These nonlinear equations incorporate the effects of the stream-wise divergence of the boundary layer. The analysis provides results for three-dimensional disturbances and also considers nonparallel effects. Results for two-dimensional disturbances demonstrate that nonparallel effects are negligible and substantiates the mechanism described by the mode-interaction theory. Nonparallel effects become significant with increasing three-dimensionality. Receptivity amplitudes are shown to be large over a broad range of surface wave numbers. When operative, this mechanism is likely to dominate the boundary-layer receptivity.

  8. SOUND-SPEED INVERSION OF THE SUN USING A NONLOCAL STATISTICAL CONVECTION THEORY

    SciTech Connect

    Zhang Chunguang; Deng Licai; Xiong Darun; Christensen-Dalsgaard, Jorgen

    2012-11-01

    Helioseismic inversions reveal a major discrepancy in sound speed between the Sun and the standard solar model just below the base of the solar convection zone. We demonstrate that this discrepancy is caused by the inherent shortcomings of the local mixing-length theory adopted in the standard solar model. Using a self-consistent nonlocal convection theory, we construct an envelope model of the Sun for sound-speed inversion. Our solar model has a very smooth transition from the convective envelope to the radiative interior, and the convective energy flux changes sign crossing the boundaries of the convection zone. It shows evident improvement over the standard solar model, with a significant reduction in the discrepancy in sound speed between the Sun and local convection models.

  9. Performance analysis of half-sweep AOR method with nonlocal discretization scheme for nonlinear two-point boundary value problem

    NASA Astrophysics Data System (ADS)

    Alibubin, M. U.; Sunarto, A.; Sulaiman, J.

    2016-06-01

    In this paper, we present the concept of Half-sweep Accelerated OverRelaxation (HSAOR) iterative method with a nonlocal discretization scheme for solving nonlinear two-point boundary value problems. Second order finite difference scheme has been used to derive the half-sweep finite difference (HSFD) approximations of the problems. Then, the nonlocal discretization scheme is applied in order to transform the system of nonlinear approximation equations into the corresponding system of linear equations. Numerical results showed that HSAOR method is superior compared to Full-sweep Gauss-seidel (FSGS), Full-sweep Successive OverRelaxation (FSSOR) and Full-sweep Accelerated Over Relaxation (FSAOR) methods.

  10. Dark matter from spacetime nonlocality

    NASA Astrophysics Data System (ADS)

    Saravani, Mehdi; Aslanbeigi, Siavash

    2015-11-01

    We propose that dark matter is not yet another new particle in nature, but that it is a remnant of quantum gravitational effects on known fields. We arrive at this possibility in an indirect and surprising manner: by considering retarded, nonlocal, and Lorentzian evolution for quantum fields. This is inspired by recent developments in causal set theory, where such an evolution shows up as the continuum limit of scalar field propagation on a background causal set. Concretely, we study the quantum theory of a massless scalar field whose evolution is given not by the the d'Alembertian □, but by an operator □˜ which is Lorentz invariant, reduces to □ at low energies, and defines an explicitly retarded evolution: (□˜ϕ )(x ) only depends on ϕ (y ), where y is in the causal past of x . This modification results in the existence of a continuum of massive particles, in addition to the usual massless ones, in the free theory. When interactions are introduced, these massive or off-shell quanta can be produced by the scattering of massless particles, but once produced, they no longer interact, which makes them a natural candidate for dark matter.

  11. Nonlocality in deuteron stripping reactions.

    PubMed

    Timofeyuk, N K; Johnson, R C

    2013-03-15

    We propose a new method for the analysis of deuteron stripping reactions, A(d,p)B, in which the nonlocality of nucleon-nucleus interactions and three-body degrees of freedom are accounted for in a consistent way. The model deals with equivalent local nucleon potentials taken at an energy shifted by ∼40  MeV from the "E(d)/2" value frequently used in the analysis of experimental data, where E(d) is the incident deuteron energy. The "E(d)/2" rule lies at the heart of all three-body analyses of (d, p) reactions performed so far with the aim of obtaining nuclear structure properties such as spectroscopic factors and asymptotic normalization coefficients that are crucial for our understanding of nuclear shell evolution in neutron- and proton-rich regions of the nuclear periodic table and for predicting the cross sections of stellar reactions. The large predicted shift arises from the large relative kinetic energy of the neutron and proton in the incident deuteron in those components of the n+p+A wave function that dominate the (d, p) reaction amplitude. The large shift reduces the effective d-A potentials and leads to a change in predicted (d, p) cross sections, thus affecting the interpretation of these reactions in terms of nuclear structure. PMID:25166525

  12. Nonlocality of orthogonal product states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Chao; Gao, Fei; Qin, Su-Juan; Yang, Ying-Hui; Wen, Qiao-Yan

    2015-07-01

    In this paper, we mainly study the local indistinguishability of mutually orthogonal product basis quantum states in d ⊗d . In 3 ⊗3 , Bennett et al. [ Phys. Rev. A 59, 1070 (1999), 10.1103/PhysRevA.59.1070] presented nine orthogonal product basis quantum states which cannot be distinguished by local operations and classical communication (LOCC). In the work by Zhang et al. [Z.-C. Zhang et al., Phys. Rev. A 90, 022313 (2014), 10.1103/PhysRevA.90.022313], this result was generalized in d ⊗d , where d is odd. In this paper, we aim to construct locally indistinguishable orthogonal product basis quantum states in d ⊗d . For the general d ⊗d (d >2 ) quantum system, we first construct 4 d -4 orthogonal product states, and prove these states are locally indistinguishable using a very simple but quite effective method. Then, based on these states, we construct some classes of locally indistinguishable orthogonal product basis quantum states (OPBS) in d ⊗d (d >2 ) . Finally, we construct some LOCC indistinguishable OPBS in multipartite quantum systems. All of the above results demonstrate the phenomenon of nonlocality without entanglement.

  13. Self-localized states for electron transfer in nonlocal continuum deformable media

    NASA Astrophysics Data System (ADS)

    Cisneros-Ake, Luis A.

    2016-08-01

    We consider the problem of electron transport in a deformable continuum medium subjected to an external harmonic substrate potential. We then consider the quasi-stationary state of the full problem to find a Gross-Pitaevskii type equation with a nonlocal external potential, which is solved by variational and numerical means (considered as the exact solution) to find the parameter conditions for the existence of self-localized solutions. The variational approach predicts a threshold on the on-site or nonlocality parameter where localized solutions cease to exist from the Non-Linear Schrödinger soliton limit. A numerical continuation of stationary state solutions in the corresponding discrete system is used to confirm the prediction of the turning value in the on-site term. We finally study the full stationary state and make use of an approximation, proposed by Briedis et al. [17], for the nonlocal term, corresponding to strong nonlocalities, to find analytic expressions for self-localized states in terms of the series solutions of a nonlinear modified Bessel equation.

  14. Influence of thermal and surface effects on vibration behavior of nonlocal rotating Timoshenko nanobeam

    NASA Astrophysics Data System (ADS)

    Ghadiri, Majid; Shafiei, Navvab; Akbarshahi, Amir

    2016-07-01

    This paper is proposed to study the free vibration of a rotating Timoshenko nanobeam based on the nonlocal theory considering thermal and surface elasticity effects. The governing equations and the related boundary conditions are derived using the Hamilton's principle. In order to solve the problem, generalized differential quadrature method is applied to discretize the governing differential equations corresponding to clamped-simply and clamped-free boundary conditions. In this article, the influences of some parameters such as nonlocal parameter, angular velocity, thickness of the nanobeam, and thermal and surface elasticity effects on the free vibration of the rotating nanobeam are investigated, and the results are compared for different boundary conditions. The results show that the surface effect and the nonlocal parameter and the temperature changes have significant roles, and they should not be ignored in the vibrational study of rotating nanobeams. Also, the angular velocity and the hub radius have more significant roles than temperature change effects on the nondimensional frequency. It is found that the nonlocal parameter behavior and the temperature change behavior on the frequency are different in the first mode for the rotating cantilever nanobeam.

  15. On the fractional generalization of Eringenʼs nonlocal elasticity for wave propagation

    NASA Astrophysics Data System (ADS)

    Challamel, Noël; Zorica, Dušan; Atanacković, Teodor M.; Spasić, Dragan T.

    2013-03-01

    A fractional nonlocal elasticity model is presented in this Note. This model can be understood as a possible generalization of Eringen's nonlocal elastic model, with a free non-integer derivative in the stress-strain fractional order differential equation. This model only contains a single length scale and the fractional derivative order as parameters. The kernel of this integral-based nonlocal model is explicitly given for various fractional derivative orders. The dynamical properties of this new model are investigated for a one-dimensional problem. It is possible to obtain an analytical dispersive equation for the axial wave problem, which is parameterized by the fractional derivative order. The fractional derivative order of this generalized fractional Eringen's law is then calibrated with the dispersive wave properties of the Born-Kármán model of lattice dynamics and appears to be greater than the one of the usual Eringen's model. An excellent matching of the dispersive curve of the Born-Kármán model of lattice dynamics is obtained with such generalized integral-based nonlocal model.

  16. Wavefunction Collapse via a Nonlocal Relativistic Variational Principle

    SciTech Connect

    Harrison, Alan K.

    2012-06-18

    Since the origin of quantum theory in the 1920's, some of its practitioners (and founders) have been troubled by some of its features, including indeterminacy, nonlocality and entanglement. The 'collapse' process described in the Copenhagen Interpretation is suspect for several reasons, and the act of 'measurement,' which is supposed to delimit its regime of validity, has never been unambiguously defined. In recent decades, nonlocality and entanglement have been studied energetically, both theoretically and experimentally, and the theory has been reinterpreted in imaginative ways, but many mysteries remain. We propose that it is necessary to replace the theory by one that is explicitly nonlinear and nonlocal, and does not distinguish between measurement and non-measurement regimes. We have constructed such a theory, for which the phase of the wavefunction plays the role of a hidden variable via the process of zitterbewegung. To capture this effect, the theory must be relativistic, even when describing nonrelativistic phenomena. It is formulated as a variational principle, in which Nature attempts to minimize the sum of two spacetime integrals. The first integral tends to drive the solution toward a solution of the standard quantum mechanical wave equation, and also enforces the Born rule of outcome probabilities. The second integral drives the collapse process. We demonstrate that the new theory correctly predicts the possible outcomes of the electron two-slit experiment, including the infamous 'delayed-choice' variant. We observe that it appears to resolve some long-standing mysteries, but introduces new ones, including possible retrocausality (a cause later than its effect). It is not clear whether the new theory is deterministic.

  17. Time dependent wave envelope finite difference analysis of sound propagation

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J.

    1984-01-01

    A transient finite difference wave envelope formulation is presented for sound propagation, without steady flow. Before the finite difference equations are formulated, the governing wave equation is first transformed to a form whose solution tends not to oscillate along the propagation direction. This transformation reduces the required number of grid points by an order of magnitude. Physically, the transformed pressure represents the amplitude of the conventional sound wave. The derivation for the wave envelope transient wave equation and appropriate boundary conditions are presented as well as the difference equations and stability requirements. To illustrate the method, example solutions are presented for sound propagation in a straight hard wall duct and in a two dimensional straight soft wall duct. The numerical results are in good agreement with exact analytical results.

  18. Maximally nonlocal theories cannot be maximally random.

    PubMed

    de la Torre, Gonzalo; Hoban, Matty J; Dhara, Chirag; Prettico, Giuseppe; Acín, Antonio

    2015-04-24

    Correlations that violate a Bell inequality are said to be nonlocal; i.e., they do not admit a local and deterministic explanation. Great effort has been devoted to study how the amount of nonlocality (as measured by a Bell inequality violation) serves to quantify the amount of randomness present in observed correlations. In this work we reverse this research program and ask what do the randomness certification capabilities of a theory tell us about the nonlocality of that theory. We find that, contrary to initial intuition, maximal randomness certification cannot occur in maximally nonlocal theories. We go on and show that quantum theory, in contrast, permits certification of maximal randomness in all dichotomic scenarios. We hence pose the question of whether quantum theory is optimal for randomness; i.e., is it the most nonlocal theory that allows maximal randomness certification? We answer this question in the negative by identifying a larger-than-quantum set of correlations capable of this feat. Not only are these results relevant to understanding quantum mechanics' fundamental features, but also put fundamental restrictions on device-independent protocols based on the no-signaling principle. PMID:25955039

  19. Comment on 'Vibration analysis of fluid-conveying double-walled carbon nanotubes based on nonlocal elastic theory'.

    PubMed

    Tounsi, Abdeloauhed; Heireche, Houari; Benzair, Abdelnour; Mechab, Ismail

    2009-11-01

    Most recently, Lee and Chang (2009 J. Phys.: Condens. Matter 21 115302) combined nonlocal theory and Euler-Bernoulli beam theory in the study of the vibration of the fluid-conveying double-walled carbon nanotube. In this recent published work, the importance of using nonlocal stress tensors consistently has been overlooked, and some ensuring relations were still presented based on the local stress components. Therefore, the governing equations and applied forces obtained in this manner are either inconsistent or incomplete. In this comment, the consistent governing equations for modelling free transverse vibration of the fluid-conveying double-walled carbon nanotube using the nonlocal Euler-Bernoulli beam model are derived. PMID:21832479

  20. Nonlocal Drag of Magnons in a Ferromagnetic Bilayer.

    PubMed

    Liu, Tianyu; Vignale, G; Flatté, Michael E

    2016-06-10

    Quantized spin waves, or magnons, in a magnetic insulator are assumed to interact weakly with the surroundings, and to flow with little dissipation or drag, producing exceptionally long diffusion lengths and relaxation times. In analogy to Coulomb drag in bilayer two-dimensional electron gases, in which the contribution of the Coulomb interaction to the electric resistivity is studied by measuring the interlayer resistivity (transresistivity), we predict a nonlocal drag of magnons in a ferromagnetic bilayer structure based on semiclassical Boltzmann equations. Nonlocal magnon drag depends on magnetic dipolar interactions between the layers and manifests in the magnon current transresistivity and the magnon thermal transresistivity, whereby a magnon current in one layer induces a chemical potential gradient and/or a temperature gradient in the other layer. The largest drag effect occurs when the magnon current flows parallel to the magnetization; however, for oblique magnon currents a large transverse current of magnons emerges. We examine the effect for practical parameters, and find that the predicted induced temperature gradient is readily observable. PMID:27341254

  1. Different kinds of chimera death states in nonlocally coupled oscillators.

    PubMed

    Premalatha, K; Chandrasekar, V K; Senthilvelan, M; Lakshmanan, M

    2016-05-01

    We investigate the significance of nonisochronicity parameter in a network of nonlocally coupled Stuart-Landau oscillators with symmetry breaking form. We observe that the presence of nonisochronicity parameter leads to structural changes in the chimera death region while varying the strength of the interaction. This gives rise to the existence of different types of chimera death states such as multichimera death state, type I periodic chimera death (PCD) state, and type II periodic chimera death state. We also find that the number of periodic domains in both types of PCD states decreases exponentially with an increase of coupling range and obeys a power law under nonlocal coupling. Additionally, we also analyze the structural changes of chimera death states by reducing the system of dynamical equations to a phase model through the phase reduction. We also briefly study the role of nonisochronicity parameter on chimera states, where the existence of a multichimera state with respect to the coupling range is pointed out. Moreover, we also analyze the robustness of the chimera death state to perturbations in the natural frequencies of the oscillators. PMID:27300886

  2. Different kinds of chimera death states in nonlocally coupled oscillators

    NASA Astrophysics Data System (ADS)

    Premalatha, K.; Chandrasekar, V. K.; Senthilvelan, M.; Lakshmanan, M.

    2016-05-01

    We investigate the significance of nonisochronicity parameter in a network of nonlocally coupled Stuart-Landau oscillators with symmetry breaking form. We observe that the presence of nonisochronicity parameter leads to structural changes in the chimera death region while varying the strength of the interaction. This gives rise to the existence of different types of chimera death states such as multichimera death state, type I periodic chimera death (PCD) state, and type II periodic chimera death state. We also find that the number of periodic domains in both types of PCD states decreases exponentially with an increase of coupling range and obeys a power law under nonlocal coupling. Additionally, we also analyze the structural changes of chimera death states by reducing the system of dynamical equations to a phase model through the phase reduction. We also briefly study the role of nonisochronicity parameter on chimera states, where the existence of a multichimera state with respect to the coupling range is pointed out. Moreover, we also analyze the robustness of the chimera death state to perturbations in the natural frequencies of the oscillators.

  3. Nonlocal Drag of Magnons in a Ferromagnetic Bilayer

    NASA Astrophysics Data System (ADS)

    Liu, Tianyu; Vignale, G.; Flatté, Michael E.

    2016-06-01

    Quantized spin waves, or magnons, in a magnetic insulator are assumed to interact weakly with the surroundings, and to flow with little dissipation or drag, producing exceptionally long diffusion lengths and relaxation times. In analogy to Coulomb drag in bilayer two-dimensional electron gases, in which the contribution of the Coulomb interaction to the electric resistivity is studied by measuring the interlayer resistivity (transresistivity), we predict a nonlocal drag of magnons in a ferromagnetic bilayer structure based on semiclassical Boltzmann equations. Nonlocal magnon drag depends on magnetic dipolar interactions between the layers and manifests in the magnon current transresistivity and the magnon thermal transresistivity, whereby a magnon current in one layer induces a chemical potential gradient and/or a temperature gradient in the other layer. The largest drag effect occurs when the magnon current flows parallel to the magnetization; however, for oblique magnon currents a large transverse current of magnons emerges. We examine the effect for practical parameters, and find that the predicted induced temperature gradient is readily observable.

  4. Multifamily Envelope Leakage Model

    SciTech Connect

    Faakye, Omari; Griffiths, Dianne

    2015-05-08

    “The cost for blower testing is high, because it is labor intensive, and it may disrupt occupants in multiple units. This high cost and disruption deter program participants, and dissuade them from pursuing energy improvements that would trigger air leakage testing, such as improvements to the building envelope.” This statement found in a 2012 report by Heschong Mahone Group for several California interests emphasizes the importance of reducing the cost and complexity of blower testing in multifamily buildings. Energy efficiency opportunities are being bypassed. The cost of single blower testing is on the order of $300. The cost for guarded blower door testing—the more appropriate test for assessing energy savings opportunities—could easily be six times that, and that’s only if you have the equipment and simultaneous access to multiple apartments. Thus, the proper test is simply not performed. This research seeks to provide an algorithm for predicting the guarded blower door test result based upon a single, total blower door test.

  5. Nonlocal Markovian models for image denoising

    NASA Astrophysics Data System (ADS)

    Salvadeo, Denis H. P.; Mascarenhas, Nelson D. A.; Levada, Alexandre L. M.

    2016-01-01

    Currently, the state-of-the art methods for image denoising are patch-based approaches. Redundant information present in nonlocal regions (patches) of the image is considered for better image modeling, resulting in an improved quality of filtering. In this respect, nonlocal Markov random field (MRF) models are proposed by redefining the energy functions of classical MRF models to adopt a nonlocal approach. With the new energy functions, the pairwise pixel interaction is weighted according to the similarities between the patches corresponding to each pair. Also, a maximum pseudolikelihood estimation of the spatial dependency parameter (β) for these models is presented here. For evaluating this proposal, these models are used as an a priori model in a maximum a posteriori estimation to denoise additive white Gaussian noise in images. Finally, results display a notable improvement in both quantitative and qualitative terms in comparison with the local MRFs.

  6. Hardy's criterion of nonlocality for mixed states

    SciTech Connect

    Ghirardi, GianCarlo; Marinatto, Luca

    2006-03-15

    We generalize Hardy's proof of nonlocality to the case of bipartite mixed statistical operators, and we exhibit a necessary condition which has to be satisfied by any given mixed state {sigma} in order that a local and realistic hidden variable model exists which accounts for the quantum mechanical predictions implied by {sigma}. Failure of this condition will imply both the impossibility of any local explanation of certain joint probability distributions in terms of hidden variables and the nonseparability of the considered mixed statistical operator. Our result can be also used to determine the maximum amount of noise, arising from imperfect experimental implementations of the original Hardy's proof of nonlocality, in presence of which it is still possible to put into evidence the nonlocal features of certain mixed states.

  7. Nonlocal continuum-based modeling of a nanoplate subjected to a moving nanoparticle. Part I: Theoretical formulations

    NASA Astrophysics Data System (ADS)

    Kiani, Keivan

    2011-10-01

    The potential applications of nanoplates in energy storage, chemical and biological sensors, solar cells, field emission, and transporting of nanocars have been attracted the attentions of the nanotechnology community to them during recent years. Herein, the later application of nanoplates from nonlocal elastodynamic point of view is of interest. To this end, dynamic response of a nanoplate subjected to a moving nanoparticle is examined within the context of nonlocal continuum theory of Eringen. The fully simply supported nanoplate is modeled based on the nonlocal Kirchhoff, Mindlin, and higher-order plate theories. The non-dimensional equations of motion of the nonlocal plate models are established. The effects of moving nanoparticle's weight and existing friction between the surfaces of the moving nanoparticle and nanoplate on the in-plane and out-of-plane vibrations of the nanoplate are incorporated into the formulations of the proposed models. The eigen function expansion and the Laplace transform methods are employed for discretization of the governing equations in the spatial and the time domains, respectively. The analytical expressions of the dynamic deformation field associated with each nonlocal plate theory are obtained when the moving nanoparticle traverses the nanoplate on an arbitrary straight path (an opened path) as well as an ellipse path (a closed path). The dynamic in-plane forces and moments of each nonlocal plate model are also derived. Furthermore, the critical velocity and the critical angular velocity of the moving nanoparticle for the proposed models are expressed analytically for the aforementioned paths. Part II of this work consists in a comprehensive parametric study where the effects of influential parameters on dynamic response of the proposed nonlocal plate models are scrutinized in some detail.

  8. Nonlocal formulation of spin Coulomb drag

    NASA Astrophysics Data System (ADS)

    D'Amico, I.; Ullrich, C. A.

    2013-10-01

    The spin Coulomb drag (SCD) effect occurs in materials and devices where charged carriers with different spins exchange momentum via Coulomb scattering. This causes frictional forces between spin-dependent currents that lead to intrinsic dissipation, which may limit spintronics applications. A nonlocal formulation of SCD is developed which is valid for strongly inhomogeneous systems such as nanoscale spintronics devices. This nonlocal formulation of SCD is successfully applied to linewidths of intersubband spin plasmons in semiconductor quantum wells, where experiments have shown that the local approximation fails.

  9. Reversed rainbow with a nonlocal metamaterial

    NASA Astrophysics Data System (ADS)

    Morgado, Tiago A.; Marcos, João S.; Costa, João T.; Costa, Jorge R.; Fernandes, Carlos A.; Silveirinha, Mário G.

    2014-12-01

    One of the intriguing potentials of metamaterials is the possibility to realize a nonlocal electromagnetic reaction, such that the effective medium response at a given point is fundamentally entangled with the macroscopic field distribution at long distances. Here, it is experimentally and numerically verified that a microwave nonlocal metamaterial formed by crossed metallic wires enables a low-loss broadband anomalous material response such that the refractive index decreases with frequency. Notably, it is shown that an electromagnetic beam refracted by our metamaterial prism creates a reversed microwave rainbow.

  10. Experimental nonlocal and surreal Bohmian trajectories.

    PubMed

    Mahler, Dylan H; Rozema, Lee; Fisher, Kent; Vermeyden, Lydia; Resch, Kevin J; Wiseman, Howard M; Steinberg, Aephraim

    2016-02-01

    Weak measurement allows one to empirically determine a set of average trajectories for an ensemble of quantum particles. However, when two particles are entangled, the trajectories of the first particle can depend nonlocally on the position of the second particle. Moreover, the theory describing these trajectories, called Bohmian mechanics, predicts trajectories that were at first deemed "surreal" when the second particle is used to probe the position of the first particle. We entangle two photons and determine a set of Bohmian trajectories for one of them using weak measurements and postselection. We show that the trajectories seem surreal only if one ignores their manifest nonlocality. PMID:26989784

  11. Reversed rainbow with a nonlocal metamaterial

    SciTech Connect

    Morgado, Tiago A. Marcos, João S.; Silveirinha, Mário G.; Costa, João T.; Costa, Jorge R.; Fernandes, Carlos A.

    2014-12-29

    One of the intriguing potentials of metamaterials is the possibility to realize a nonlocal electromagnetic reaction, such that the effective medium response at a given point is fundamentally entangled with the macroscopic field distribution at long distances. Here, it is experimentally and numerically verified that a microwave nonlocal metamaterial formed by crossed metallic wires enables a low-loss broadband anomalous material response such that the refractive index decreases with frequency. Notably, it is shown that an electromagnetic beam refracted by our metamaterial prism creates a reversed microwave rainbow.

  12. Observational viability and stability of nonlocal cosmology

    SciTech Connect

    Deser, S.; Woodard, R.P. E-mail: woodard@phys.ufl.edu

    2013-11-01

    We show that the nonlocal gravity models, proposed to explain current cosmic acceleration without dark energy, pass two essential tests: first, they can be defined so as not to alter the, observationally correct, general relativity predictions for gravitationally bound systems. Second, they are stable, ghost-free, with no additional excitations beyond those of general relativity. In this they differ from their, ghostful, localized versions. The systems' initial value constraints are the same as in general relativity, and our nonlocal modifications never convert the original gravitons into ghosts.

  13. Compressive Sensing via Nonlocal Smoothed Rank Function.

    PubMed

    Fan, Ya-Ru; Huang, Ting-Zhu; Liu, Jun; Zhao, Xi-Le

    2016-01-01

    Compressive sensing (CS) theory asserts that we can reconstruct signals and images with only a small number of samples or measurements. Recent works exploiting the nonlocal similarity have led to better results in various CS studies. To better exploit the nonlocal similarity, in this paper, we propose a non-convex smoothed rank function based model for CS image reconstruction. We also propose an efficient alternating minimization method to solve the proposed model, which reduces a difficult and coupled problem to two tractable subproblems. Experimental results have shown that the proposed method performs better than several existing state-of-the-art CS methods for image reconstruction. PMID:27583683

  14. Experimental nonlocal and surreal Bohmian trajectories

    PubMed Central

    Mahler, Dylan H.; Rozema, Lee; Fisher, Kent; Vermeyden, Lydia; Resch, Kevin J.; Wiseman, Howard M.; Steinberg, Aephraim

    2016-01-01

    Weak measurement allows one to empirically determine a set of average trajectories for an ensemble of quantum particles. However, when two particles are entangled, the trajectories of the first particle can depend nonlocally on the position of the second particle. Moreover, the theory describing these trajectories, called Bohmian mechanics, predicts trajectories that were at first deemed “surreal” when the second particle is used to probe the position of the first particle. We entangle two photons and determine a set of Bohmian trajectories for one of them using weak measurements and postselection. We show that the trajectories seem surreal only if one ignores their manifest nonlocality. PMID:26989784

  15. Non-locality Sudden Death in Tripartite Systems

    SciTech Connect

    Jaeger, Gregg; Ann, Kevin

    2009-03-10

    Bell non-locality sudden death is the disappearance of non-local properties in finite times under local phase noise, which decoheres states only in the infinite-time limit. We consider the relationship between decoherence, disentanglement, and Bell non-locality sudden death in bipartite and tripartite systems in specific large classes of state preparation.

  16. Nonlinear nonlocal vibration of embedded DWCNT conveying fluid using shell model

    NASA Astrophysics Data System (ADS)

    Ghorbanpour Arani, A.; Zarei, M. Sh.; Amir, S.; Khoddami Maraghi, Z.

    2013-02-01

    In this work nonlinear vibration of double-walled carbon nanotube (DWCNT) embedded in an elastic medium and subjected to an axial fluid flow (incompressible and non-viscose) is investigated. The elastic medium is simulated using Pasternak foundation in which adjacent layer interactions are assumed to have been coupled by van der Waals (VdW) force. The higher-order equation of motion is derived using Hamilton's principle and nonlocal-nonlinear shell theory. Galerkin and averaging methods are adopted to solve the higher-order governing equations. Elastic medium, small scale parameter, velocity and fluid density are taken into account to calculate the effects of axial and circumferential wave numbers in this study. Results reveal that increasing circumferential wave number, leads to enhanced nonlinearity. Critical flow velocities of DWCNT are inversely related to the non-local parameter (e0a), so that increase in the later lead to reduced critical flow velocities.

  17. Some optical properties of metal in non-local potential theory

    NASA Astrophysics Data System (ADS)

    Chrzanowski, Janusz

    2007-04-01

    On the grounds of the non-local potential we can obtain a modified Schrödinger equation which allows on simple turn to the transform domain. Thereby the total energy of electron understood in terms of quasiparticle becomes an explicit function of the wave number. In result the response of the metal surface to the external electromagnetic radiation one can analyze in more general way.

  18. A nonlocal electron conduction model for multidimensional radiation hydrodynamics codes

    NASA Astrophysics Data System (ADS)

    Schurtz, G. P.; Nicolaï, Ph. D.; Busquet, M.

    2000-10-01

    Numerical simulation of laser driven Inertial Confinement Fusion (ICF) related experiments require the use of large multidimensional hydro codes. Though these codes include detailed physics for numerous phenomena, they deal poorly with electron conduction, which is the leading energy transport mechanism of these systems. Electron heat flow is known, since the work of Luciani, Mora, and Virmont (LMV) [Phys. Rev. Lett. 51, 1664 (1983)], to be a nonlocal process, which the local Spitzer-Harm theory, even flux limited, is unable to account for. The present work aims at extending the original formula of LMV to two or three dimensions of space. This multidimensional extension leads to an equivalent transport equation suitable for easy implementation in a two-dimensional radiation-hydrodynamic code. Simulations are presented and compared to Fokker-Planck simulations in one and two dimensions of space.

  19. Nonlocal analysis of finite-beam-driven instabilities

    NASA Technical Reports Server (NTRS)

    Serizawa, Y.; Dum, C. T.

    1992-01-01

    The fully kinetic integral eigenmode equation in wave-number space is used to describe the nonlocal behavior of electrostatic waves in an electron-beam plasma, which are studied in the low-temperature-beam regime and the warm-beam regime. The case of strongly magnetized electrons and unmagnetized ions, which corresponds to the waves in a frequency range from the lower-hybrid to the electron plasma frequency, is examined. Three wave modes are found. The first group consists of modes that have dispersive properties similar to the uniform, infinite beam-plasma system. Depending on the beam width, the growth rates are strongly reduced. The second group, surface modes, are localized at the periphery of the beam region and are less unstable than the unstable modes of the first group. The third group represents natural oscillations of the background plasma. These modes are virtually unaffected by the beam.

  20. Electron-energy loss study of nonlocal effects in connected plasmonic nanoprisms.

    PubMed

    Wiener, Aeneas; Duan, Huigao; Bosman, Michel; Horsfield, Andrew P; Pendry, John B; Yang, Joel K W; Maier, Stefan A; Fernández-Domínguez, Antonio I

    2013-07-23

    We investigate the emergence of nonlocal effects in plasmonic nanostructures through electron-energy loss spectroscopy. To theoretically describe the spatial dispersion in the metal permittivity, we develop a full three-dimensional nonlocal hydrodynamic solution of Maxwell's equations in frequency domain that implements the electron beam as a line current source. We use our numerical approach to perform an exhaustive analysis of the impact of nonlocality in the plasmonic response of single triangular prisms and connected bowtie dimers. Our results demonstrate the complexity of the interplay between nonlocal and geometric effects taking place in these structures. We show the different sensitivities to both effects of the various plasmonic modes supported by these systems. Finally, we present an experimental electron-energy loss study on gold nanoprisms connected by bridges as narrow as 1.6 nm. The comparison with our theoretical predictions enables us to reveal in a phenomenological fashion the enhancement of absorption damping that occurs in these atomistic junctions due to quantum confinement and grain boundary electron scattering. PMID:23782059

  1. Optical-soliton and chaotic motions in a nonlocal nonlinear medium

    NASA Astrophysics Data System (ADS)

    Zhen, Hui-Ling; Tian, Bo; Xie, Xi-Yang; Liu, Lei

    2016-05-01

    The coupled equations for the incoherent optical spatial solitons in a nonlocal nonlinear medium is studied analytically. With the soliton solutions hereby obtained via the symbolic computation, the optical-soliton motion in the nonlocal nonlinear medium is studied: ? is inversely related to ?, ?, and ?, while ? is positively related to ? and ?, but ? is independent of ?, with ? as the slowly varying amplitude of the beam, ? as the refractive index change, ? as the beam intensity distribution, ? as the frequency of the propagating beam, and ? as the unperturbed refractive index. Head-on and overtaking interactions are observed, and head-on interaction is transformed into an overtaking one with ? increasing. Bound-state interaction is displayed, and with ? increasing, the period of ? decreases, while that of ? increases. Considering the external forces in the nonlocal nonlinear medium, we explore the chaotic motions in the nonlinear nonlocal medium, including effects of the external forces on such motions. It is seen that when ? and ?, the two-dimensional attractors with stretching-and-folding structures are exhibited, and the developed chaos occurs, where ? and ? are the amplitudes of external forces, c is the speed of light in vacuum. Such chaotic motions are weakened with ?, ?, ?, and ? increasing, or with ? decreasing, where ? and ? represent the frequencies of external forces.

  2. Modeling of Carbon Nanotube Composites Based on Nonlocal Elasticity Approach

    NASA Astrophysics Data System (ADS)

    Alavinasab, Ali; Jha, Ratneshwar; Ahmadi, G.

    2014-01-01

    Nonlocal continuum theory is studied for modeling stress distributions in nanocomposites. The second-order approximation in nonlocal theory is considered since the first-order approximation leads to an unacceptable solution. A representative volume element (RVE) of CNT composite is utilized to derive unknown constants in the nonlocal theory model. Stress distributions in RVE using nonlocal theory, classical elasticity, and finite element method are obtained. All three approaches yield the same force, but classical elasticity gives an incorrect value of first moment. Wave propagation studies show that the dispersion curve obtained by nonlocal theory is quite close to the atomic Born-von Karman model.

  3. Spiraling multivortex solitons in nonlocal nonlinear media.

    PubMed

    Buccoliero, Daniel; Desyatnikov, Anton S; Krolikowski, Wieslaw; Kivshar, Yuri S

    2008-01-15

    We demonstrate the existence of a broad class of higher-order rotating spatial solitons in nonlocal nonlinear media. We employ the generalized Hermite-Laguerre-Gaussian ansatz for constructing multivortex soliton solutions and study numerically their dynamics and stability. We discuss in detail the tripole soliton carrying two spiraling phase dislocations, or self-trapped optical vortices. PMID:18197238

  4. Nonlocality and entanglement via the Unruh effect

    SciTech Connect

    Tian, Zehua; Wang, Jieci; Jing, Jiliang

    2013-05-15

    Modeling the qubit by a two-level semiclassical detector coupled to a massless scalar field, we investigate how the Unruh effect affects the nonlocality and entanglement of two-qubit and three-qubit states when one of the entangled qubits is accelerated. Two distinct differences with the results of free field model in non-inertial frames are (i) for the two-qubit state, the CHSH inequality cannot be violated for sufficiently large but finite acceleration, furthermore, the concurrence will experience “sudden death”; and (ii) for the three-qubit state, not only does the entanglement vanish in the infinite acceleration limit, but also the Svetlichny inequality cannot be violated in the case of large acceleration. -- Highlights: ► We compare entanglement and nonlocality of two-level detector model with that of free field model in noninertial frame. ► Two-qubit state entanglement experiences “sudden death”. ► Three-qubit state entanglement vanishes in the infinite acceleration limit. ► Bipartite nonlocal correlations vanish for finite values of the acceleration. ► Tripartite nonlocal correlations vanish for finite values of the acceleration as well.

  5. Resonant and nonlocal properties of phononic metasolids

    NASA Astrophysics Data System (ADS)

    Torrent, Daniel; Pennec, Yan; Djafari-Rouhani, Bahram

    2015-11-01

    We derive a general theory of effective properties in metasolids based on phononic crystals with low frequency resonances. We demonstrate that in general these structures need to be described by means of a frequency-dependent and nonlocal anisotropic mass density, stiffness tensor and a third-rank coupling tensor, which shows that they behave like a nonlocal Willis medium. The effect of nonlocality and coupling tensor manifest themselves for some particular resonances, whereas they become negligible for other resonances. Considering the example of a two-dimensional phononic crystal, consisting of triangular arrangements of cylindrical shells in an elastic matrix, we show that its mass density tensor is strongly resonant and anisotropic presenting both positive and negative divergent values, while becoming scalar in the quasistatic limit. Moreover, it is found that the negative value of transverse component of the mass density is induced by a dipolar resonance, while that of the vertical component is induced by a monopolar one. Finally, the dispersion relation obtained by the effective parameters of the crystal is compared with the band structure, showing good agreement for the low-wave-number region, although the nonlocal effects are important given the existence of some resonant values of the wave number.

  6. 29 CFR 780.320 - Nonlocal minors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... That Is Exempted From the Minimum Wage and Overtime Pay Requirements Under Section 13(a)(6) Statutory... 29 Labor 3 2010-07-01 2010-07-01 false Nonlocal minors. 780.320 Section 780.320 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY...

  7. 29 CFR 780.320 - Nonlocal minors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... That Is Exempted From the Minimum Wage and Overtime Pay Requirements Under Section 13(a)(6) Statutory... 29 Labor 3 2014-07-01 2014-07-01 false Nonlocal minors. 780.320 Section 780.320 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY...

  8. 29 CFR 780.320 - Nonlocal minors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... That Is Exempted From the Minimum Wage and Overtime Pay Requirements Under Section 13(a)(6) Statutory... 29 Labor 3 2011-07-01 2011-07-01 false Nonlocal minors. 780.320 Section 780.320 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY...

  9. 29 CFR 780.320 - Nonlocal minors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... That Is Exempted From the Minimum Wage and Overtime Pay Requirements Under Section 13(a)(6) Statutory... 29 Labor 3 2013-07-01 2013-07-01 false Nonlocal minors. 780.320 Section 780.320 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY...

  10. 29 CFR 780.320 - Nonlocal minors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... That Is Exempted From the Minimum Wage and Overtime Pay Requirements Under Section 13(a)(6) Statutory... 29 Labor 3 2012-07-01 2012-07-01 false Nonlocal minors. 780.320 Section 780.320 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY...

  11. Nonlocal edge state transport in topological insulators

    NASA Astrophysics Data System (ADS)

    Protogenov, Alexander P.; Verbus, Valery A.; Chulkov, Evgueni V.

    2013-11-01

    We use the N-terminal scheme for studying the edge-state transport in two-dimensional topological insulators. We find the universal nonlocal response in the ballistic transport approach. This macroscopic exhibition of the topological order offers different areas for applications.

  12. Radiative interactions in molecular gases under local and nonlocal thermodynamic equilibrium conditions

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Jha, M. K.

    1993-01-01

    Basic formulations, analyses, and numerical procedures are presented to investigate radiative heat interactions in diatomic and polyatomic gases under local and nonlocal thermodynamic equilibrium conditions. Essential governing equations are presented for both gray and nongray gases. Information is provided on absorption models, relaxation times, and transfer equations. Radiative flux equations are developed which are applicable under local and nonlocal thermodynamic equilibrium conditions. The problem is solved for fully developed laminar incompressible flows between two parallel plates under the boundary condition of a uniform surface heat flux. For specific applications, three diatomic and three polyatomic gases are considered. The results are obtained numerically by employing the method of variation of parameters. The results are compared under local and nonlocal thermodynamic equilibrium conditions at different temperature and pressure conditions. Both gray and nongray studies are conducted extensively for all molecular gases considered. The particular gases selected for this investigation are CO, NO, OH, CO2, H2O, and CH4. The temperature and pressure range considered are 300-2000 K and 0.1-10 atmosphere, respectively. In general, results demonstrate that the gray gas approximation overestimates the effect of radiative interaction for all conditions. The conditions of NLTE, however, result in underestimation of radiative interactions. The method developed for this study can be extended to solve complex problems of radiative heat transfer involving nonequilibrium phenomena.

  13. Measuring non-local Lagrangian peak bias

    NASA Astrophysics Data System (ADS)

    Biagetti, Matteo; Chan, Kwan Chuen; Desjacques, Vincent; Paranjape, Aseem

    2014-06-01

    We investigate non-local Lagrangian bias contributions involving gradients of the linear density field, for which we have predictions from the excursion set peak formalism. We begin by writing down a bias expansion which includes all the bias terms, including the non-local ones. Having checked that the model furnishes a reasonable fit to the halo mass function, we develop a one-point cross-correlation technique to measure bias factors associated with χ2-distributed quantities. We validate the method with numerical realizations of peaks of Gaussian random fields before we apply it to N-body simulations. We focus on the lowest (quadratic) order non-local contributions -2χ _{10}(k_1\\cdot k_2) and χ _{01}[3(k_1\\cdot k_2)^2-k_1^2 k_2^2], where k_1, k_2 are wave modes. We can reproduce our measurement of χ10 if we allow for an offset between the Lagrangian halo centre-of-mass and the peak position. The sign and magnitude of χ10 is consistent with Lagrangian haloes sitting near linear density maxima. The resulting contribution to the halo bias can safely be ignored for M = 1013 M⊙ h-1, but could become relevant at larger halo masses. For the second non-local bias χ01 however, we measure a much larger magnitude than predicted by our model. We speculate that some of this discrepancy might originate from non-local Lagrangian contributions induced by non-spherical collapse.

  14. An envelope function formalism for lattice-matched heterostructures

    NASA Astrophysics Data System (ADS)

    Van de Put, Maarten L.; Vandenberghe, William G.; Magnus, Wim; Sorée, Bart

    2015-08-01

    The envelope function method traditionally employs a single basis set which, in practice, relates to a single material because the k · p matrix elements are generally only known in a particular basis. In this work, we defined a basis function transformation to alleviate this restriction. The transformation is completely described by the known inter-band momentum matrix elements. The resulting envelope function equation can solve the electronic structure in lattice matched heterostructures without resorting to boundary conditions at the interface between materials, while all unit-cell averaged observables can be calculated as with the standard envelope function formalism. In the case of two coupled bands, this heterostructure formalism is equivalent to the standard formalism while taking position dependent matrix elements.

  15. Simulation of low-pressure inductively coupled plasmas: Non-local effects and pulsed power operation

    NASA Astrophysics Data System (ADS)

    Ramamurthi, Badri

    For modeling of low-pressure Inductively Coupled Plasma (ICP) discharges, a number of approaches have been proposed with varying degree of complexity. A self-consistent 1-D model was developed in this work to study the effects of non-local electron conductivity on power absorption and plasma density profiles in a planar inductively coupled argon discharge at low pressures (< 10 mTorr). The self-consistent kinetic description of the discharge included three modules: (1) an EEDF module to compute a non-Maxwellian EEDF, (2) a non-local electron conductivity module which predicted current distribution in the plasma as an integral over the electric field and solved Maxwell's equations to find the self-consistent electric field as well as the non-local power deposition profile and (3) a Heavy Species Transport (HST) module which solved for the ion and metastable atom density and velocity. Results from the full model were then compared with those obtained by using a local conductivity model (Ohm's law) for the RF current. For 10 mTorr, the EEDF was found to be almost Maxwellian with electron temperature ˜ 3 V. As a result, the plasma density profiles obtained from the local and non-local cases were almost identical for the same total power. Interestingly, a similar result was obtained even for a pressure of 1 mTorr where the EEDF was non-Maxwellian. This suggests that as far as species density and flux are concerned, local conductivity models, with lesser computational expense, can be employed even in the non-local regime. Comparisons between simulation and experiment for RF field and current density showed better agreement for non-local model compared with local model. A two-dimensional (r,z) continuum model was then developed to study the spatio-temporal dynamics of a pulsed power (square-wave modulated) discharge in argon (electropositive) and chlorine (electronegative) sustained in an inductively coupled plasma (ICP) reactor with a planar coil. The self

  16. Hidden variables and nonlocality in quantum mechanics

    NASA Astrophysics Data System (ADS)

    Hemmick, Douglas Lloyd

    1997-05-01

    Most physicists hold a skeptical attitude toward a 'hidden variables' interpretation of quantum theory, despite David Bohm's successful construction of such a theory and John S. Bell's strong arguments in favor of the idea. The first reason for doubt concerns certain mathematical theorems (von Neumann's, Gleason's, Kochen and Specker's, and Bell's) which can be applied to the hidden variables issue. These theorems are often credited with proving that hidden variables are indeed 'impossible', in the sense that they cannot replicate the predictions of quantum mechanics. Many who do not draw such a strong conclusion nevertheless accept that hidden variables have been shown to exhibit prohibitively complicated features. The second concern is that the most sophisticated example of a hidden variables theory-that of David Bohm-exhibits non-locality, i.e., consequences of events at one place can propagate to other places instantaneously. However, neither the mathematical theorems in question nor the attribute of nonlocality detract from the importance of a hidden variables interpretation of quantum theory. Nonlocality is present in quantum mechanics itself, and is a required characteristic of any theory that agrees with the quantum mechanical predictions. We first discuss the earliest analysis of hidden variables-that of von Neumann's theorem-and review John S. Bell's refutation of von Neumann's 'impossibility proof'. We recall and elaborate on Bell's arguments regarding the theorems of Gleason, and Kochen and Specker. According to Bell, these latter theorems do not imply that hidden variables interpretations are untenable, but instead that such theories must exhibit contextuality, i.e., they must allow for the dependence of measurement results on the characteristics of both measured system and measuring apparatus. We demonstrate a new way to understand the implications of both Gleason's theorem and Kochen and Specker's theorem by noting that they prove a result we call

  17. Free vibration of fractional viscoelastic Timoshenko nanobeams using the nonlocal elasticity theory

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Faraji Oskouie, M.; Sadeghi, F.; Bazdid-Vahdati, M.

    2015-11-01

    In this article, the free vibration of a fractional viscoelastic Timoshenko nanobeam is studied through inserting fractional calculus as a viscoelastic material compatibility equations in nonlocal beam theory. The material properties of a single-walled carbon nanotube (SWCNT) are used and two solution procedures are proposed to solve the obtained equations in the time domain. The former is a semi-analytical approach in which the Galerkin scheme is employed to discretize the governing equations in the spatial domain and the obtained set of ordinary differential equations is solved using a direct numerical integration scheme. On the contrary, the latter is entirely numerical in which the governing equations of system on the spatial and time domains are first discretized using general differential quadrature (GDQ) technique and finite difference (FD) scheme, respectively and then the set of algebraic equations is solved to arrive at the time response of system under different boundary conditions. Considering the second solution procedure as the main approach, its validity and accuracy are verified by the semi-analytical approach which is more difficult to enter various boundary conditions. Numerical results are also presented to get an insight into the effects of fractional derivative order, nonlocal parameter, viscoelasticity coefficient and nanobeam length on the time response of fractional viscoelastic Timoshenko nanobeams under different boundary conditions.

  18. Size-dependent geometrically nonlinear free vibration analysis of fractional viscoelastic nanobeams based on the nonlocal elasticity theory

    NASA Astrophysics Data System (ADS)

    Ansari, R.; Faraji Oskouie, M.; Gholami, R.

    2016-01-01

    In recent decades, mathematical modeling and engineering applications of fractional-order calculus have been extensively utilized to provide efficient simulation tools in the field of solid mechanics. In this paper, a nonlinear fractional nonlocal Euler-Bernoulli beam model is established using the concept of fractional derivative and nonlocal elasticity theory to investigate the size-dependent geometrically nonlinear free vibration of fractional viscoelastic nanobeams. The non-classical fractional integro-differential Euler-Bernoulli beam model contains the nonlocal parameter, viscoelasticity coefficient and order of the fractional derivative to interpret the size effect, viscoelastic material and fractional behavior in the nanoscale fractional viscoelastic structures, respectively. In the solution procedure, the Galerkin method is employed to reduce the fractional integro-partial differential governing equation to a fractional ordinary differential equation in the time domain. Afterwards, the predictor-corrector method is used to solve the nonlinear fractional time-dependent equation. Finally, the influences of nonlocal parameter, order of fractional derivative and viscoelasticity coefficient on the nonlinear time response of fractional viscoelastic nanobeams are discussed in detail. Moreover, comparisons are made between the time responses of linear and nonlinear models.

  19. Heat Recovery in Building Envelopes

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2001-01-01

    Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. Previous laboratory and simulation research has indicated that such heat transfer between the infiltrating air and walls may be substantial. In this study, Computational Fluid Dynamics was used to simulate sensible heat transfer in typical envelope constructions. The results show that the traditional method may over-predict the infiltration energy load by up to 95 percent at low leakage rates. A simplified physical model has been developed and used to predict the infiltration heat recovery based on the Peclet number of the flow and the fraction of the building envelope active in infiltration heat recovery.

  20. Role of nonlocality and Landau damping in the dynamics of a quantum dot coupled to surface plasmons

    NASA Astrophysics Data System (ADS)

    Vagov, A.; Larkin, I. A.; Croitoru, M. D.; Axt, V. M.

    2016-05-01

    We investigate the dynamics of a quantum emitter (quantum dot) placed in the vicinity of a flat metal surface. The dynamics is induced by the coupling between the emitter and surface plasmon-polaritons. The plasmon-polariton modes are described within a continuous media model with a nonlocal Lindhard-type dielectric response of the metal. The analytic solution of the dynamical equations is obtained in the rotating wave approximation. The results demonstrate a considerable influence of the nonlocality of the electromagnetic response and the Landau damping in the metal. In particular, the relaxation dynamics is characterized by two distinct times that may differ by large amounts as a consequence of the nonlocality of the response. It is also shown that one of the contributions to the relaxation can have a power-law long-time asymptote, leading to notable changes in the dynamical pattern.

  1. A model for high temperature creep of single crystal superalloys based on nonlocal damage and viscoplastic material behavior

    NASA Astrophysics Data System (ADS)

    Trinh, B. T.; Hackl, K.

    2014-07-01

    A model for high temperature creep of single crystal superalloys is developed, which includes constitutive laws for nonlocal damage and viscoplasticity. It is based on a variational formulation, employing potentials for free energy, and dissipation originating from plasticity and damage. Evolution equations for plastic strain and damage variables are derived from the well-established minimum principle for the dissipation potential. The model is capable of describing the different stages of creep in a unified way. Plastic deformation in superalloys incorporates the evolution of dislocation densities of the different phases present. It results in a time dependence of the creep rate in primary and secondary creep. Tertiary creep is taken into account by introducing local and nonlocal damage. Herein, the nonlocal one is included in order to model strain localization as well as to remove mesh dependence of finite element calculations. Numerical results and comparisons with experimental data of the single crystal superalloy LEK94 are shown.

  2. Envelope function method for electrons in slowly-varying inhomogeneously deformed crystals.

    PubMed

    Li, Wenbin; Qian, Xiaofeng; Li, Ju

    2014-11-12

    We develop a new envelope-function formalism to describe electrons in slowly-varying inhomogeneously strained semiconductor crystals. A coordinate transformation is used to map a deformed crystal back to a geometrically undeformed structure with deformed crystal potential. The single-particle Schrödinger equation is solved in the undeformed coordinates using envelope function expansion, wherein electronic wavefunctions are written in terms of strain-parametrized Bloch functions modulated by slowly varying envelope functions. Adopting a local approximation of the electronic structure, the unknown crystal potential in the Schrödinger equation can be replaced by the strain-parametrized Bloch functions and the associated strain-parametrized energy eigenvalues, which can be constructed from unit-cell level ab initio or semi-empirical calculations of homogeneously deformed crystals at a chosen crystal momentum. The Schrödinger equation is then transformed into a coupled differential equation for the envelope functions and solved as a generalized matrix eigenvector problem. As the envelope functions are slowly varying, a coarse spatial or Fourier grid can be used to represent the envelope functions, enabling the method to treat relatively large systems. We demonstrate the effectiveness of this method using a one-dimensional model, where we show that the method can achieve high accuracy in the calculation of energy eigenstates with relatively low cost compared to direct diagonalization of the Hamiltonian. We further derive envelope function equations that allow the method to be used empirically, in which case certain parameters in the envelope function equations will be fitted to experimental data. PMID:25336522

  3. Envelope Inflation or Stellar Wind?

    NASA Astrophysics Data System (ADS)

    Ro, S.; Matzner, C. D.

    We an optically-thick, transonic, steady wind model for a H-free Wolf-Rayet star. A bifurcation is found across a critical mass loss rate Mb. Slower winds M < Mb extend by several hydrostatic stellar radii, reproduce features of envelope in ation from Petrovic et al. (2006) and Gräfener et al. (2012), and are energetically unbound. This work is of particular interest for extended envelopes and winds, radiative hydrodynamic instabilities (eg. wind stagnation, clumping, etc.), and NLTE atmospheric models.

  4. Carbon chemistry of circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Bieging, John H.

    1990-01-01

    The chemical composition of envelopes surrounding cool evolved stars, as determined from microwave spectroscopic observations, is reviewed. Emphasis is placed on recent observations with the new large mm-wavelength telescopes and interferometer arrays, and on new theoretical work, especially concerning ion-molecule chemistry of carbon-bearing in these envelopes. Thermal (as opposed to maser) emission lines are discussed. Much progress has been made in the past few years in the theoretical understanding of these objects. It is already clear, however, that observations with the new generation of mm-telescopes will require substantial improvements in the theoretical models to achieve a thorough understanding of the data now becoming available.

  5. Classification of scalar and dyadic nonlocal optical response models.

    PubMed

    Wubs, M

    2015-11-30

    Nonlocal optical response is one of the emerging effects on the nanoscale for particles made of metals or doped semiconductors. Here we classify and compare both scalar and tensorial nonlocal response models. In the latter case the nonlocality can stem from either the longitudinal response, the transverse response, or both. In phenomenological scalar models the nonlocal response is described as a smearing out of the commonly assumed infinitely localized response, as characterized by a distribution with a finite width. Here we calculate explicitly whether and how tensorial models, such as the hydrodynamic Drude model and generalized nonlocal optical response theory, follow this phenomenological description. We find considerable differences, for example that nonlocal response functions, in contrast to simple distributions, assume negative and complex values. Moreover, nonlocal response regularizes some but not all diverging optical near fields. We identify the scalar model that comes closest to the hydrodynamic model. Interestingly, for the hydrodynamic Drude model we find that actually only one third (1/3) of the free-electron response is smeared out nonlocally. In that sense, nonlocal response is stronger for transverse and scalar nonlocal response models, where the smeared-out fractions are 2/3 and 3/3, respectively. The latter two models seem to predict novel plasmonic resonances also below the plasma frequency, in contrast to the hydrodynamic model that predicts standing pressure waves only above the plasma frequency. PMID:26698757

  6. Non-locality and locality in the stochastic interpretation of quantum mechanics

    NASA Astrophysics Data System (ADS)

    Bohm, D.; Hiley, B. J.

    1989-01-01

    We review the stochastic interpretation of the quantum theory and show that, like the causal interpretation it necessarily involves non-locality. We compare and contrast our approach with that of Nelson. We then extend the stochastic interpretation to the Pauli equation. This lays the ground for a further extension to the Dirac equation and therefore enables us to discuss this interpretation in a relativistic context. We find that a co consistent treatment of non-locality can be given and that it is indeed possible further to regard this non-locality as a limiting case of a purely local theory in which the transmission of what we have called active information is not restricted to the speed of light. In this case both quantum theory and relativity come out as very good statistical approximations. However, because this basically local theory implies that these latter are not exactly valid, it is possible to propose tests that could in principle distinguish such a theory from the current theories.

  7. Free vibration of shallow and deep curved FG nanobeam via nonlocal Timoshenko curved beam model

    NASA Astrophysics Data System (ADS)

    Hosseini, S. A. H.; Rahmani, O.

    2016-03-01

    A free vibration analysis of shallow and deep curved functionally graded (FG) nanobeam is presented. Differential equations and boundary conditions are obtained using Hamilton's principle, and then, nonlocal theory is employed to derive differential equations in small scale. Properties of the material are FG in radial direction. In order to investigate the effects of deep curved beam, extensional stiffness, bending-extension coupling stiffness, and bending stiffness are calculated in the deep case, analytically. By employing Navier method, an analytical solution is presented. Results are compared and validated with available studies, and a good agreement is seen. The influences of effective parameters such as geometrical deep term, nonlocal parameter, opening angle, aspect ratio, mode number, and gradient index are discussed in detail. It is found that the frequency of deep curved nanobeam is higher than that of shallow one, and the aspect ratio significantly affects this difference to decrease. Also, it is concluded that the opening angle, nonlocal parameter, and power gradient index can notably influence the amount of frequency.

  8. Molecular decay rate near nonlocal plasmonic particles.

    PubMed

    Girard, Christian; Cuche, Aurélien; Dujardin, Erik; Arbouet, Arnaud; Mlayah, Adnen

    2015-05-01

    When the size of metal nanoparticles is smaller than typically 10 nm, their optical response becomes sensitive to both spatial dispersion and quantum size effects associated with the confinement of the conduction electrons inside the particle. In this Letter, we propose a nonlocal scheme to compute molecular decay rates near spherical nanoparticles which includes the electron-electron interactions through a simple model of electronic polarizabilities. The plasmonic particle is schematized by a dynamic dipolar polarizability α(NL)(ω), and the quantum system is characterized by a two-level system. In this scheme, the light matter interaction is described in terms of classical field susceptibilities. This theoretical framework could be extended to address the influence of nonlocality on the dynamics of quantum systems placed in the vicinity of nano-objects of arbitrary morphologies. PMID:25927799

  9. Nonlocal polarization interferometer for entanglement detection

    SciTech Connect

    Williams, Brian P.; Humble, Travis S.; Grice, Warren P.

    2014-10-30

    We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometer's unique correlation dependence on the antidiagonal elements of the density matrix, which have distinct bounds for separable states and unique values for the four Bell states. The interferometer consists of two spatially separated balanced Mach-Zehnder or Sagnac interferometers that share a polarization-entangled source. Correlations between these interferometers exhibit nonlocal interference, while single-photon interference is suppressed. This interferometer also allows for a unique version of the Clauser-Horne-Shimony-Holt Bell test where the local reality is the photon polarization. In conclusion, we present the relevant theory and experimental results.

  10. Nonlocal polarization interferometer for entanglement detection

    NASA Astrophysics Data System (ADS)

    Williams, Brian P.; Humble, Travis S.; Grice, Warren P.

    2014-10-01

    We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometer's unique correlation dependence on the antidiagonal elements of the density matrix, which have distinct bounds for separable states and unique values for the four Bell states. The interferometer consists of two spatially separated balanced Mach-Zehnder or Sagnac interferometers that share a polarization-entangled source. Correlations between these interferometers exhibit nonlocal interference, while single-photon interference is suppressed. This interferometer also allows for a unique version of the Clauser-Horne-Shimony-Holt-Bell test where the local reality is the photon polarization. We present the relevant theory and experimental results.

  11. Nonlocality of orthogonal product basis quantum states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Chao; Gao, Fei; Tian, Guo-Jing; Cao, Tian-Qing; Wen, Qiao-Yan

    2014-08-01

    In this paper, we mainly study the local indistinguishability of mutually orthogonal product basis quantum states in the high-dimensional quantum systems. In the Hilbert space of 3⊗3, Walgate and Hardy [Phys. Rev. Lett. 89, 147901 (2002), 10.1103/PhysRevLett.89.147901] presented a very simple proof for nonlocality of nine orthogonal product basis quantum states which are given by Bennett et al. [Phys. Rev. A 59, 1070 (1999), 10.1103/PhysRevA.59.1070]. In the quantum system of d⊗d, where d is odd, we construct d2 orthogonal product basis quantum states and prove these states are locally indistinguishable. Then we are able to construct some locally indistinguishable product basis quantum states in the multipartite systems. All these results reveal the phenomenon of "nonlocality without entanglement."

  12. Sampling Quantum Nonlocal Correlations with High Probability

    NASA Astrophysics Data System (ADS)

    González-Guillén, C. E.; Jiménez, C. H.; Palazuelos, C.; Villanueva, I.

    2016-05-01

    It is well known that quantum correlations for bipartite dichotomic measurements are those of the form {γ=(< u_i,v_jrangle)_{i,j=1}^n}, where the vectors u i and v j are in the unit ball of a real Hilbert space. In this work we study the probability of the nonlocal nature of these correlations as a function of {α=m/n}, where the previous vectors are sampled according to the Haar measure in the unit sphere of {R^m}. In particular, we prove the existence of an {α_0 > 0} such that if {α≤ α_0}, {γ} is nonlocal with probability tending to 1 as {n→ ∞}, while for {α > 2}, {γ} is local with probability tending to 1 as {n→ ∞}.

  13. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, Ł.; Pawłowski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

    Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose an alternative perspective for studying quantum entanglement: distributed computation of functions without communication between nodes. To formalize this approach, we propose identity games. Surprisingly, despite no signaling, we obtain that nonlocal quantum strategies beat classical ones in terms of winning probability for identity games originating from certain bipartite and multipartite functions. Moreover we show that, for a majority of functions, access to general nonsignaling resources boosts success probability two times in comparison to classical ones for a number of large enough outputs. Because there are no constraints on the inputs and no processing of the outputs in the identity games, they detect very strong types of correlations: absolute nonlocality.

  14. Nonlocal polarization interferometer for entanglement detection

    DOE PAGESBeta

    Williams, Brian P.; Humble, Travis S.; Grice, Warren P.

    2014-10-30

    We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometer's unique correlation dependence on the antidiagonal elements of the density matrix, which have distinct bounds for separable states and unique values for the four Bell states. The interferometer consists of two spatially separated balanced Mach-Zehnder or Sagnac interferometers that share a polarization-entangled source. Correlations between these interferometers exhibit nonlocal interference, while single-photon interference is suppressed. This interferometer also allows for a unique version of the Clauser-Horne-Shimony-Holt Bell test where the local reality is the photon polarization. In conclusion, wemore » present the relevant theory and experimental results.« less

  15. Nonlocal soliton scattering in random potentials

    NASA Astrophysics Data System (ADS)

    Piccardi, Armando; Residori, Stefania; Assanto, Gaetano

    2016-07-01

    We experimentally investigate the transport behaviour of nonlocal spatial optical solitons when launched in and interacting with propagation-invariant random potentials. The solitons are generated in nematic liquid crystals; the randomness is created by suitably engineered illumination of planar voltage-biased cells equipped with a photosensitive wall. We find that the fluctuations follow a super-diffusive trend, with the mean square displacement lowering for decreasing spatial correlation of the noise.

  16. EPR paradox, quantum nonlocality and physical reality

    NASA Astrophysics Data System (ADS)

    Kupczynski, M.

    2016-03-01

    Eighty years ago Einstein, Podolsky and Rosen demonstrated that instantaneous reduction of wave function, believed to describe completely a pair of entangled physical systems, led to EPR paradox. The paradox disappears in statistical interpretation of quantum mechanics (QM) according to which a wave function describes only an ensemble of identically prepared physical systems. QM predicts strong correlations between outcomes of measurements performed on different members of EPR pairs in far-away locations. Searching for an intuitive explanation of these correlations John Bell analysed so called local realistic hidden variable models and proved that correlations consistent with these models satisfy Bell inequalities which are violated by some predictions of QM and by experimental data. Several different local models were constructed and inequalities proven. Some eminent physicists concluded that Nature is definitely nonlocal and that it is acting according to a law of nonlocal randomness. According to these law perfectly random, but strongly correlated events, can be produced at the same time in far away locations and a local and causal explanation of their occurrence cannot be given. We strongly disagree with this conclusion and we prove the contrary by analysing in detail some influential finite sample proofs of Bell and CHSH inequalities and so called Quantum Randi Challenges. We also show how one can win so called Bell's game without violating locality of Nature. Nonlocal randomness is inconsistent with local quantum field theory, with standard model in elementary particle physics and with causal laws and adaptive dynamics prevailing in the surrounding us world. The experimental violation of Bell-type inequalities does not prove the nonlocality of Nature but it only confirms a contextual character of quantum observables and gives a strong argument against counterfactual definiteness and against a point of view according to which experimental outcomes are produced

  17. Nonlocal dynamics of p-adic strings

    NASA Astrophysics Data System (ADS)

    Dragovich, B. G.

    2010-09-01

    We consider the construction of Lagrangians that might be suitable for describing the entire p-adic sector of an adelic open scalar string. These Lagrangians are constructed using the Lagrangian for p-adic strings with an arbitrary prime number p. They contain space-time nonlocality because of the d’Alembertian in the argument of the Riemann zeta function. We present a brief review and some new results.

  18. Nonlocality of cluster states of qubits

    SciTech Connect

    Scarani, Valerio; Acin, Antonio; Schenck, Emmanuel; Aspelmeyer, Markus

    2005-04-01

    We investigate cluster states of qubits with respect to their nonlocal properties. We demonstrate that a Greenberger-Horne-Zeilinger (GHZ) argument holds for any cluster state: more precisely, it holds for any partial, thence mixed, state of a small number of connected qubits (five, in the case of one-dimensional lattices). In addition, we derive a Bell inequality that is maximally violated by the four-qubit cluster state and is not violated by the four-qubit GHZ state.

  19. Switching non-local vector median filter

    NASA Astrophysics Data System (ADS)

    Matsuoka, Jyohei; Koga, Takanori; Suetake, Noriaki; Uchino, Eiji

    2016-04-01

    This paper describes a novel image filtering method that removes random-valued impulse noise superimposed on a natural color image. In impulse noise removal, it is essential to employ a switching-type filtering method, as used in the well-known switching median filter, to preserve the detail of an original image with good quality. In color image filtering, it is generally preferable to deal with the red (R), green (G), and blue (B) components of each pixel of a color image as elements of a vectorized signal, as in the well-known vector median filter, rather than as component-wise signals to prevent a color shift after filtering. By taking these fundamentals into consideration, we propose a switching-type vector median filter with non-local processing that mainly consists of a noise detector and a noise removal filter. Concretely, we propose a noise detector that proactively detects noise-corrupted pixels by focusing attention on the isolation tendencies of pixels of interest not in an input image but in difference images between RGB components. Furthermore, as the noise removal filter, we propose an extended version of the non-local median filter, we proposed previously for grayscale image processing, named the non-local vector median filter, which is designed for color image processing. The proposed method realizes a superior balance between the preservation of detail and impulse noise removal by proactive noise detection and non-local switching vector median filtering, respectively. The effectiveness and validity of the proposed method are verified in a series of experiments using natural color images.

  20. Delayed-choice Measurement and Temporal Nonlocality

    NASA Astrophysics Data System (ADS)

    Kim, Ilki; Mahler, Günter

    2001-02-01

    We study for a composite quantum system with a quantum Turing architecture the temporal non-locality of quantum mechanics by using the temporal Bell inequality, which will be derived for a discretized network dynamics by identifying the subsystem indices with (discrete) parameter time. However, the direct "observation" of the quantum system will lead to no violation of the temporal Bell inequality and to consistent histories of any subsystem. Its violation can be demonstrated, though, for a delayedchoice measurement

  1. Exact solutions and spacetime singularities in nonlocal gravity

    NASA Astrophysics Data System (ADS)

    Li, Yao-Dong; Modesto, Leonardo; Rachwał, Lesław

    2015-12-01

    We hereby study exact solutions in a wide range of local higher-derivative and weakly nonlocal gravitational theories. In particular, we give a list of exact classical solutions for two classes of gravitational theories both weakly nonlocal, unitary, and super-renormalizable (or finite) at quantum level. We prove that maximally symmetric spacetimes are exact solutions in both classes, while in dimension higher than four we can also have Anti-de Sitter solutions in the presence of positive cosmological constant. It is explicitly shown under which conditions flat and Ricci-flat spacetimes are exact solutions of the equation of motion (EOM) for the first class of theories not involving the Weyl tensor in the action. We find that the well-known physical spacetimes like Schwarzschild, Kerr, (Anti-) de Sitter serve as solutions for standard matter content, when the EOM does not contain the Riemann tensor alone (operators made out of only the Riemann tensor.) We pedagogically show how to obtain these exact solutions. Furthermore, for the second class of gravity theories, with terms in the Lagrangian written using Weyl tensors, the Friedmann-Robertson-Walker (FRW) spacetimes are also exact solutions (exactly in the same way like in Einstein theory), when the matter content is given by conformal matter (radiation). We also comment on rather inevitable presence and universality of singularities and possible resolution of them in finite and conformally invariant theories. "Delocalization" is proposed as a way to solve the black hole singularity problem in the first class. In order to solve the problem of cosmological singularities in the second class, it seems crucial to have a conformally invariant or asymptotically free quantum gravitational theory.

  2. Lipschitz regularity of solutions for mixed integro-differential equations

    NASA Astrophysics Data System (ADS)

    Barles, Guy; Chasseigne, Emmanuel; Ciomaga, Adina; Imbert, Cyril

    We establish new Hölder and Lipschitz estimates for viscosity solutions of a large class of elliptic and parabolic nonlinear integro-differential equations, by the classical Ishii-Lions's method. We thus extend the Hölder regularity results recently obtained by Barles, Chasseigne and Imbert (2011). In addition, we deal with a new class of nonlocal equations that we term mixed integro-differential equations. These equations are particularly interesting, as they are degenerate both in the local and nonlocal term, but their overall behavior is driven by the local-nonlocal interaction, e.g. the fractional diffusion may give the ellipticity in one direction and the classical diffusion in the complementary one.

  3. Nonlocal modeling of granular flows down inclines.

    PubMed

    Kamrin, Ken; Henann, David L

    2015-01-01

    Flows of granular media down a rough inclined plane demonstrate a number of nonlocal phenomena. We apply the recently proposed nonlocal granular fluidity model to this geometry and find that the model captures many of these effects. Utilizing the model's dynamical form, we obtain a formula for the critical stopping height of a layer of grains on an inclined surface. Using an existing parameter calibration for glass beads, the theoretical result compares quantitatively to existing experimental data for glass beads. This provides a stringent test of the model, whose previous validations focused on driven steady-flow problems. For layers thicker than the stopping height, the theoretical flow profiles display a thickness-dependent shape whose features are in agreement with previous discrete particle simulations. We also address the issue of the Froude number of the flows, which has been shown experimentally to collapse as a function of the ratio of layer thickness to stopping height. While the collapse is not obvious, two explanations emerge leading to a revisiting of the history of inertial rheology, which the nonlocal model references for its homogeneous flow response. PMID:25376561

  4. Quantum nonlocality of multipartite orthogonal product states

    NASA Astrophysics Data System (ADS)

    Xu, Guang-Bao; Wen, Qiao-Yan; Qin, Su-Juan; Yang, Ying-Hui; Gao, Fei

    2016-03-01

    Local distinguishability of orthogonal quantum states is an area of active research in quantum information theory. However, most of the relevant results are about local distinguishability in bipartite Hilbert space and very little is known about the multipartite case. In this paper we present a generic method to construct a completable n -partite (n ≥3 ) product basis with only 2 n members, which exhibits nonlocality without entanglement with n parties, each holding a system of any finite dimension. We give an effective proof of the nonlocality of the completable multipartite product basis. In addition, we construct another incomplete multipartite product basis with a smaller number of members that cannot be distinguished by local operations and classical communication in a d1⊗d2⊗⋯⊗dn quantum system, where n ≥3 and di≥2 for i =1 ,2 ,...,n . The results can lead to a better understanding of the phenomenon of nonlocality without entanglement in any multipartite quantum system.

  5. The basic properties of non-local parametrization of a turbulent exchange

    NASA Astrophysics Data System (ADS)

    Voloshchuk, V. M.; Boychenko, S. G.; Voloshchuk, I. V.

    2010-07-01

    At mathematical modeling of the dispersion of gas-aerosol impurity is used basically local parameterization of a turbulent exchange. In this case is supposed, that of a turbulent diffusion flow is proportional to a gradient of defunding substances concentration (n). This assumption is applicable only then when the characteristic size (l) of inhomogeneities of n essentially exceeds the characteristic size L of turbulent "moles". However, at solution of various applied problems rather frequently meet situations, when l ? L. It is natural, that in this case parameterization of a turbulent exchange should have non-local character. In this research one of possible scheme of non-local parameterizations of a turbulent exchange for situations, when l ~ L, is supposed and proved. This scheme is based on idea of representation of a turbulent flow j as Fredholm's convolution of function n and the function K, describing intensity of turbulent fluctuation of environment, namely j = - grad ? K(r -- ?)? dV, where V is a volume of dispersion of a gas-aerosol impurity, r?V, ? ? V, integrating carried out on a variable ? grad is the linear differential vector-operator (gradient) influencing on a variable r (other representation grad=?/?r), the function K is a non-local analogue of coefficient of diffusion (this function at L ? l ? 0 turn to Dirac's delta-function). The problems for which it is possible to receive the analytical solution of the equation of diffusion with the supposed non-local parameterizations of a turbulent exchange are formulated. The solutions of these problems are based on an opportunity of application of Fourier's transformation of the equation of diffusion. The analysis of these solutions is carried out with the purpose of an establishment what new features during a turbulent exchange appear at their mathematical modeling with the help of non-local parameterizations. It is proved, that for a situation l ? L the adequate mathematical modeling of a turbulent

  6. Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas

    SciTech Connect

    Del Sorbo, D.; Feugeas, J.-L.; Nicolaï, Ph.; Olazabal-Loumé, M.; Dubroca, B.; Guisset, S.; Touati, M.; Tikhonchuk, V.

    2015-08-15

    Hydrodynamic simulations of high-energy-density plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified Fokker-Planck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman H-theorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ion-acoustic waves, driven by the heat flux, are presented and compared with the classical formula.

  7. Non-local Effects in a Stratified Glow Discharge With Dusty Particles

    SciTech Connect

    Sukhinin, G. I.; Fedoseev, A. V.; Ramazanov, T. S.; Amangaliyeva, R. Zh.; Dosbolayev, M. K.; Jumabekov, A. N.

    2008-09-07

    The work is aimed to describe non-local effects in the positive column of a low pressure stratified DC glow discharge in argon with dusty particles in a vertical cylindrical discharge tube. The numerical calculations of plasma parameters in the axis of the discharge tube were performed with the help of hybrid model based on the solution of non-local Boltzmann equation for EEDF. Distributions of optical emission from striations were measured experimentally. It is shown that in a stratified positive column the EEDF is not Maxwellian and even non-monotonous. Also, the effect of displacing of optical emission distribution relative to the electric field is shown both by numerical simulation and experimental measurements.

  8. Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas

    NASA Astrophysics Data System (ADS)

    Del Sorbo, D.; Feugeas, J.-L.; Nicolaï, Ph.; Olazabal-Loumé, M.; Dubroca, B.; Guisset, S.; Touati, M.; Tikhonchuk, V.

    2015-08-01

    Hydrodynamic simulations of high-energy-density plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified Fokker-Planck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman H-theorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ion-acoustic waves, driven by the heat flux, are presented and compared with the classical formula.

  9. The auxiliary Hamiltonian approach and its generalization to non-local self-energies

    NASA Astrophysics Data System (ADS)

    Balzer, Karsten

    2016-03-01

    The recently introduced auxiliary Hamiltonian approach [Balzer K and Eckstein M 2014 Phys. Rev. B 89 035148] maps the problem of solving the two-time Kadanoff-Baym equations onto a noninteracting auxiliary system with additional bath degrees of freedom. While the original paper restricts the discussion to spatially local self-energies, we show that there exists a rather straightforward generalization to treat also non-local correlation effects. The only drawback is the loss of time causality due to a combined singular value and eigen decomposition of the two-time self-energy, the application of which inhibits one to establish the self-consistency directly on the time step. For derivation and illustration of the method, we consider the Hubbard model in one dimension and study the decay of the Néel state in the weak-coupling regime, using the local and non-local second-order Born approximation.

  10. Prediction of negative dispersion by a nonlocal poroelastic theory.

    PubMed

    Chakraborty, Abir

    2008-01-01

    The objective of this work is to show that the negative dispersion of ultrasonic waves propagating in cancellous bone can be explained by a nonlocal version of Biot's theory of poroelasticity. The nonlocal poroelastic formulation is presented in this work and the exact solutions for one- and two-dimensional systems are obtained by the method of Fourier transform. The nonlocal phase speeds for solid- and fluid-borne waves show the desired negative dispersion where the magnitude of dispersion is strongly dependent on the nonlocal parameters and porosity. Dependence of the phase speed and attenuation is studied for both porosity and frequency variation. It is shown that the nonlocal parameter can be easily estimated by comparing the theoretical dispersion rate with experimental observations. It is also shown that the modes of Lamb waves show similar negative dispersion when predicted by the nonlocal poroelastic theory. PMID:18177138

  11. Connection between Bell nonlocality and Bayesian game theory.

    PubMed

    Brunner, Nicolas; Linden, Noah

    2013-01-01

    In 1964, Bell discovered that quantum mechanics is a nonlocal theory. Three years later, in a seemingly unconnected development, Harsanyi introduced the concept of Bayesian games. Here we show that, in fact, there is a deep connection between Bell nonlocality and Bayesian games, and that the same concepts appear in both fields. This link offers interesting possibilities for Bayesian games, namely of allowing the players to receive advice in the form of nonlocal correlations, for instance using entangled quantum particles or more general no-signalling boxes. This will lead to novel joint strategies, impossible to achieve classically. We characterize games for which nonlocal resources offer a genuine advantage over classical ones. Moreover, some of these strategies represent equilibrium points, leading to the notion of quantum/no-signalling Nash equilibrium. Finally, we describe new types of question in the study of nonlocality, namely the consideration of nonlocal advantage given a set of Bell expressions. PMID:23820748

  12. Imaging nonlocal transport in graphene using scanning gate microscopy

    NASA Astrophysics Data System (ADS)

    Connolly, Malcolm; Dou, Ziwei; Morikawa, Sei; Wang, Shu-Wei; Smith, Charles; Watanabe, Kenji; Taniguchi, Takashi; Masubuchi, Satoru; Machida, Tomoki

    Nonlocal transport measurements are designed to detect when charge injected by a current probe induces voltages far from the classical current path. While a range of exotic forces can induce nonlocal transport of Dirac fermions in graphene such as bandstructure topology, Zeeman spin Hall, and many-body interactions, it is important to understand the role of density fluctuations around the Dirac point where nonlocality can be most pronounced. We use scanning gate microscopy to image current flow and nonlocal signals directly in high-mobility graphene encapsulated by hexagonal boron nitride. Despite being located several mean-free paths from the current injector, Hall voltage probes parallel with current path display an order of magnitude larger nonlocal signal than expected around the Dirac point. SGM images captured at different carrier density are consistent with current spreading due to percolation. Such long range charge transport should be considered when designing devices and calculating the relaxation length of nonlocal currents. Supported by EPSRC.

  13. Nonlocal transport in dual-gated bilayer graphene

    NASA Astrophysics Data System (ADS)

    Shimazaki, Yuya; Yamamoto, Michihisa; Watanabe, Kenji; Taniguchi, Takashi; Tarucha, Seigo

    2014-03-01

    We report nonlocal transport measurement of biased bilayer graphene. Dual gated bilayer graphene Hall bars sandwiched between two h-BN insulating layers were prepared using the transfer technique with PMMA thin flims. We measured both local and non-local transport at temperatures between 1.5 K and 200 K. We found enhancement of the nonlocal resistance near the charge neutrality point when we increase the perpendicular electric field. Observed nonlocal resistance at 70K is much larger than what is expected as the Ohmic contribution from van der Pauw formula with measured local resistivity. This observation indicates additional contribution to the nonlocal transport in biased bilayer graphene. We present temperature and displacement field dependence of the nonlocal resistance and discuss its origin in terms of valley Hall effect and transport through disordered edge states.

  14. Gap solitons under competing local and nonlocal nonlinearities

    SciTech Connect

    Kuo, Kuan-Hsien; Lin Yuanyao; Lee, Ray-Kuang; Malomed, Boris A.

    2011-05-15

    We analyze the existence, bifurcations, and shape transformations of one-dimensional gap solitons (GSs) in the first finite band gap induced by a periodic potential built into materials with local self-focusing and nonlocal self-defocusing nonlinearities. Originally stable on-site GS modes become unstable near the upper edge of the band gap with the introduction of the nonlocal self-defocusing nonlinearity with a small nonlocality radius. Unstable off-site GSs bifurcate into a new branch featuring single-humped, double-humped, and flat-top modes due to the competition between local and nonlocal nonlinearities. The mechanism underlying the complex bifurcation pattern and cutoff effects (termination of some bifurcation branches) is illustrated in terms of the shape transformation under the action of the varying degree of the nonlocality. The results of this work suggest a possibility of optical-signal processing by means of the competing nonlocal and local nonlinearities.

  15. Origins of Nonlocality Near the Neutrality Point in Graphene

    NASA Astrophysics Data System (ADS)

    Folk, Joshua

    Nonlocal measurements are an effective experimental tool for probing non-charge characteristics of carriers using a (charge) transport measurement. For example, nonlocal signals in a Hall bar geometry can indicate spin currents, or valley currents, or heat currents flowing through a sample without an accompanying charge current. We present an experimental study of nonlocal electrical signals near the Dirac point in graphene, with the goal of disentangling the various types of current that might give rise to nonlocality. The in-plane magnetic field dependence of the nonlocal signal confirms the role of spin in this effect, as expected from predictions of the Zeeman spin Hall effect in graphene, but our experiments show that thermo-magneto-electric effects also contribute to nonlocality, and the effect is sometimes stronger than that due to spin.

  16. Monogamy of Measurement-Induced Nonlocality Based on Relative Entropy

    NASA Astrophysics Data System (ADS)

    Luo, Yu; Xi, Zheng-Jun; Li, Yong-Ming

    2014-11-01

    In this paper, using relative entropy, we study monogamous properties of measurement-induced nonlocality based on relative entropy. Depending on different measurement sides, we provide necessary and sufficient conditions for two types of monogamy inequalities. By the concept of nonlocality monogamy score, we find a necessary condition of the vanished nonlocality monogamy score for arbitrary three-party states. In addition, two types of necessary and sufficient conditions of the vanished nonlocality monogamy scores are obtained for any pure states. As an application, we show that measurement-induced nonlocality based on relative entropy can be viewed as a “nonlocality witness” to distinguish generalized GHZ states from the generalized W states.

  17. On the solvability of a nonlocal boundary value problem for the Laplace operator with opposite flows at the part of the boundary

    NASA Astrophysics Data System (ADS)

    Dildabek, Gulnar; Orazov, Isabek

    2016-08-01

    In the present paper, we investigate a nonlocal boundary problem for the Laplace equation in a half-disk, with opposite flows at the part of the boundary. The difference of this problem is the impossibility of direct applying of the Fourier method (separation of variables). Because the corresponding spectral problem for the ordinary differential equation has the system of eigenfunctions not forming a basis. A special system of functions based on these eigenfunctions is constructed. This system has already formed the basis. This new basis is used for solving the nonlocal boundary value problem. The existence and the uniqueness of the classical solution of the problem are proved.

  18. Pattern formation in a model of competing populations with nonlocal interactions

    NASA Astrophysics Data System (ADS)

    Segal, B. L.; Volpert, V. A.; Bayliss, A.

    2013-06-01

    We analyze and compute an extension of a previously developed population model based on the well-known diffusive logistic equation with nonlocal interaction, to a system involving competing species. Our model involves a system of nonlinear integro-differential equations, with the nonlocal interaction characterized by convolution integrals of the population densities against specified kernel functions. The extent of the nonlocal coupling is characterized by a parameter δ so that when δ→0 the problem becomes local. We consider critical points of the model, i.e., spatially homogeneous equilibrium solutions. There is generally one critical point in the first quadrant (i.e., both population densities positive), denoting coexistence of the two species. We show that this solution can be destabilized by the nonlocal coupling and obtain general conditions for stability of this critical point as a function of δ, the specific kernel function and parameters of the model. We study the nonlinear behavior of the model and show that the populations can evolve to localized cells, or islands. We find that the stability transition is supercritical. Near the stability boundary solutions are small amplitude, nearly sinusoidal oscillations, however, when δ increases large amplitude, nonlinear states are found. We find a multiplicity of stable, steady state patterns. We further show that with a stepfunction kernel function the structure of these islands, a highly nonlinear phenomenon, can be described analytically. Finally, we analyze the role of the kernel function and show that for some choices of kernel function the resulting population islands can exhibit tip-splitting behavior and island amplitude modulation.

  19. Continuous time random walks for non-local radial solute transport

    NASA Astrophysics Data System (ADS)

    Dentz, Marco; Kang, Peter K.; Le Borgne, Tanguy

    2015-08-01

    This study formulates and analyzes continuous time random walk (CTRW) models in radial flow geometries for the quantification of non-local solute transport induced by heterogeneous flow distributions and by mobile-immobile mass transfer processes. To this end we derive a general CTRW framework in radial coordinates starting from the random walk equations for radial particle positions and times. The particle density, or solute concentration is governed by a non-local radial advection-dispersion equation (ADE). Unlike in CTRWs for uniform flow scenarios, particle transition times here depend on the radial particle position, which renders the CTRW non-stationary. As a consequence, the memory kernel characterizing the non-local ADE, is radially dependent. Based on this general formulation, we derive radial CTRW implementations that (i) emulate non-local radial transport due to heterogeneous advection, (ii) model multirate mass transfer (MRMT) between mobile and immobile continua, and (iii) quantify both heterogeneous advection in a mobile region and mass transfer between mobile and immobile regions. The expected solute breakthrough behavior is studied using numerical random walk particle tracking simulations. This behavior is analyzed by explicit analytical expressions for the asymptotic solute breakthrough curves. We observe clear power-law tails of the solute breakthrough for broad (power-law) distributions of particle transit times (heterogeneous advection) and particle trapping times (MRMT model). The combined model displays two distinct time regimes. An intermediate regime, in which the solute breakthrough is dominated by the particle transit times in the mobile zones, and a late time regime that is governed by the distribution of particle trapping times in immobile zones. These radial CTRW formulations allow for the identification of heterogeneous advection and mobile-immobile processes as drivers of anomalous transport, under conditions relevant for field tracer

  20. Light steering in a strongly nonlocal nonlinear medium

    SciTech Connect

    Ouyang Shigen; Hu Wei; Guo Qi

    2007-11-15

    With a strongly nonlocal model, we present an analytical solution of the coherent interaction of two Gaussian beams with an arbitrary phase difference and arbitrary incident angles. Numerical simulations show that the analytical solution can describe the interaction of two Gaussian beams very well in the strongly nonlocal case. It is theoretically shown that one can steer lights in strongly nonlocal media by tuning the incident conditions of coherently interacting beams like the phase difference between beams and their relative amplitude.

  1. Exact solutions for a coupled nonlocal model of nanobeams

    SciTech Connect

    Marotti de Sciarra, Francesco E-mail: raffaele.barretta@unina.it; Barretta, Raffaele E-mail: raffaele.barretta@unina.it

    2014-10-06

    BERNOULLI-EULER nanobeams under concentrated forces/couples with the nonlocal constitutive behavior proposed by ERINGEN do not exhibit small-scale effects. A new model obtained by coupling the ERINGEN and gradient models is formulated in the present note. A variational treatment is developed by imposing suitable thermodynamic restrictions for nonlocal models and the ensuing differential and boundary conditions of elastic equilibrium are provided. The nonlocal elastostatic problem is solved in a closed-form for nanocantilever and clamped nanobeams.

  2. Gravity and large-scale nonlocal bias

    NASA Astrophysics Data System (ADS)

    Chan, Kwan Chuen; Scoccimarro, Román; Sheth, Ravi K.

    2012-04-01

    For Gaussian primordial fluctuations the relationship between galaxy and matter overdensities, bias, is most often assumed to be local at the time of observation in the large-scale limit. This hypothesis is however unstable under time evolution, we provide proofs under several (increasingly more realistic) sets of assumptions. In the simplest toy model galaxies are created locally and linearly biased at a single formation time, and subsequently move with the dark matter (no velocity bias) conserving their comoving number density (no merging). We show that, after this formation time, the bias becomes unavoidably nonlocal and nonlinear at large scales. We identify the nonlocal gravitationally induced fields in which the galaxy overdensity can be expanded, showing that they can be constructed out of the invariants of the deformation tensor (Galileons), the main signature of which is a quadrupole field in second-order perturbation theory. In addition, we show that this result persists if we include an arbitrary evolution of the comoving number density of tracers. We then include velocity bias, and show that new contributions appear; these are related to the breaking of Galilean invariance of the bias relation, a dipole field being the signature at second order. We test these predictions by studying the dependence of halo overdensities in cells of fixed dark matter density: measurements in simulations show that departures from the mean bias relation are strongly correlated with the nonlocal gravitationally induced fields identified by our formalism, suggesting that the halo distribution at the present time is indeed more closely related to the mass distribution at an earlier rather than present time. However, the nonlocality seen in the simulations is not fully captured by assuming local bias in Lagrangian space. The effects on nonlocal bias seen in the simulations are most important for the most biased halos, as expected from our predictions. Accounting for these

  3. Cosmological evolution of generalized non-local gravity

    NASA Astrophysics Data System (ADS)

    Zhang, Xue; Wu, Ya-Bo; Li, Song; Liu, Yu-Chen; Chen, Bo-Hai; Chai, Yun-Tian; Shu, Shuang

    2016-07-01

    We construct a class of generalized non-local gravity (GNLG) model which is the modified theory of general relativity (GR) obtained by adding a term m2n‑2 R□‑nR to the Einstein-Hilbert action. Concretely, we not only study the gravitational equation for the GNLG model by introducing auxiliary scalar fields, but also analyse the classical stability and examine the cosmological consequences of the model for different exponent n. We find that the half of the scalar fields are always ghost-like and the exponent n must be taken even number for a stable GNLG model. Meanwhile, the model spontaneously generates three dominant phases of the evolution of the universe, and the equation of state parameters turn out to be phantom-like. Furthermore, we clarify in another way that exponent n should be even numbers by the spherically symmetric static solutions in Newtonian gauge. It is worth stressing that the results given by us can include ones in refs. [28, 34] as the special case of n=2.

  4. Heuristic theory of nonlocally broken gyro-Bohm scaling

    SciTech Connect

    Waltz, R.E.; Candy, J.

    2005-07-15

    Global gyrokinetic simulations of ion temperature gradient turbulent transport with piecewise-flat profiles are given to illustrate the breaking of gyro-Bohm scaling by a nonlocal mechanism. The nonlocal drainage of the turbulence from unstable regions spreading into stable (or less unstable) regions breaks the gyro-Bohm scaling toward Bohm in unstable regions and toward super-gyro-Bohm in stable (or less unstable) regions. A heuristic model for this nonlocal process is formulated in terms of a nonlocal growth rate resulting from a locally weighted radial average of the local linear ballooning mode growth rate. A nonlocality length L measured in ion gyroradii provides the exponential scale for the local weighting. The nonlocal growth rate can be incorporated into a local gyro-Bohm-scaled transport model in place of the local growth rate. The resulting nonlocal transport model will provide some transport in stable regions. A heuristic theory of this nonlocal transport mechanism based on the partial formation of global modes in toroidal geometry is detailed. The theory argues that the nonlocality length L increases with relative gyroradius and decreases with the linear growth rate.

  5. ACCELERATED MRI USING ITERATIVE NON-LOCAL SHRINKAGE

    PubMed Central

    Mohsin, Yasir Q.; Ongie, Gregory; Jacob, Mathews

    2015-01-01

    We introduce a fast iterative non-local shrinkage algorithm to recover MRI data from undersampled Fourier measurements. This approach is enabled by the reformulation of current non-local schemes as an alternating algorithm to minimize a global criterion. The proposed algorithm alternates between a non-local shrinkage step and a quadratic subproblem. The resulting algorithm is observed to be considerably faster than current alternating non-local algorithms. We use efficient continuation strategies to minimize local minima issues. The comparisons of the proposed scheme with state-of-the-art regularization schemes show a considerable reduction in alias artifacts and preservation of edges. PMID:25570265

  6. Survey on nonlocal games and operator space theory

    NASA Astrophysics Data System (ADS)

    Palazuelos, Carlos; Vidick, Thomas

    2016-01-01

    This review article is concerned with a recently uncovered connection between operator spaces, a noncommutative extension of Banach spaces, and quantum nonlocality, a striking phenomenon which underlies many of the applications of quantum mechanics to information theory, cryptography, and algorithms. Using the framework of nonlocal games, we relate measures of the nonlocality of quantum mechanics to certain norms in the Banach and operator space categories. We survey recent results that exploit this connection to derive large violations of Bell inequalities, study the complexity of the classical and quantum values of games and their relation to Grothendieck inequalities, and quantify the nonlocality of different classes of entangled states.

  7. Circumferential nonlocal effect on the buckling and vibration of nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, Cheng Yuan; Li, Xiao Hu; Luo, Ying

    2016-04-01

    The nonlocal beam theories are widely used to study the mechanics of cylindrical nanotubes (NTs). The one-dimensional models however are unable to account for the nonlocal effect in the circumferential direction, which may substantially affect the applicability of the nonlocal beam models. To address the issue this letter examines the circumferential nonlocal effect (CNE) on the buckling and vibration of the NTs. Here the CNE is characterized by the difference between the nonlocal beam model considering the axial nonlocal effect only and the nonlocal shell model with both axial and circumferential nonlocal effects. The aspect ratio and radius-dependence of the CNE are calculated for the singlewall carbon NTs selected as a typical example. The results show that the CNE is substantial for the buckling and vibration of the NTs with small radius (e.g., <1 nm) and aspect ratio (e.g., <15). It however decreases with the rising radius and the aspect ratio, and turns out to be small for relatively wide and long NTs. The nonlocal beam theories thus may overestimate the buckling load and vibration frequency for the thin and short NTs.

  8. Dynamics of the Kuramoto equation with spatially distributed control

    NASA Astrophysics Data System (ADS)

    Kashchenko, Ilia; Kaschenko, Sergey

    2016-05-01

    We consider the scalar complex equation with spatially distributed control. Its dynamical properties are studied by asymptotic methods when the control coefficient is either sufficiently large or sufficiently small and the function of distribution is either almost symmetric or significantly nonsymmetric relative to zero. In all cases we reduce original equation to quasinormal form - the family of special parabolic equations, which do not contain big and small parameters, which nonlocal dynamics determines the behaviour of solutions of the original equation.

  9. Laboratory tests of short intense envelope solitons

    NASA Astrophysics Data System (ADS)

    Slunyaev, A.; Clauss, G. F.; Klein, M.; Onorato, M.

    2012-04-01

    Stability of short intense nonlinear wave groups propagating over deep water is tested in laboratory runs which are performed in the facility of the Technical University of Berlin. The strongly nonlinear simulation of quasi-steady nonlinear wave groups within the framework of the Euler equations is used to generate the surface elevation time series at a border of the water tank. Besides, the exact analytic solution of the nonlinear Schrodinger equation is used for this purpose. The time series is then transformed to a wave maker signal with use of a designed transfer algorithm. Wave group propagation along the tank was recorded by 4 distant gauges and by an array of 6 densely situated gauges. This setup allows to consider the wave evolution from 10 to 85 m from the wave maker, and to obtain the wave envelope shape directly from the instrumental data. In the experiments wave groups were characterized by the steepness values up to kAcr < 0.32 and kAtr < 0.24, where k is the mean wavenumber, Acr is the crest amplitude, and Atr is the trough amplitude; and the maximum local wave slope was up to 0.34. Wave breaking phenomenon was not observed in the experiments. Different mean wave numbers and wave groups of different intensities were considered. In some cases the wave groups exhibit noticeable radiation in the course of propagation, though the groups are not dispersed fully. The effect of finite water depth is found to be significant on the wave group stability. Intense wave groups have shorter time of adjustment, what in some sense may help them to manifest their individuality clearer. The experimental tests confirm recent numerical simulations of fully nonlinear equations, where very steep stable single and interacting nonlinear wave groups were reported [1-3]. The quasi-stationary wave groups observed in numerical and laboratory experiments are strongly nonlinear analogues of the nonlinear Schrodinger envelope solitons. The results emphasize the importance of long

  10. Safeguards Envelope Progress FY08

    SciTech Connect

    Robert Bean; Richard Metcalf; Aaron Bevill

    2008-09-01

    The Safeguards Envelope Project met its milestones by creating a rudimentary safeguards envelope, proving the value of the approach on a small scale, and determining the most appropriate path forward. The Idaho Chemical Processing Plant’s large cache of reprocessing process monitoring data, dubbed UBER Data, was recovered and used in the analysis. A probabilistic Z test was used on a Markov Monte Carlo simulation of expected diversion data when compared with normal operating data. The data regarding a fully transient event in a tank was used to create a simple requirement, representative of a safeguards envelope, whose impact was a decrease in operating efficiency by 1.3% but an increase in material balance period of 26%. This approach is operator, state, and international safeguards friendly and should be applied to future reprocessing plants. Future requirements include tank-to-tank correlations in reprocessing facilities, detailed operations impact studies, simulation inclusion, automated optimization, advanced statistics analysis, and multi-attribute utility analysis.

  11. Fundamental monogamy relation between contextuality and nonlocality.

    PubMed

    Kurzyński, Paweł; Cabello, Adán; Kaszlikowski, Dagomir

    2014-03-14

    We show that the no-disturbance principle imposes a tradeoff between locally contextual correlations violating the Klyachko-Can-Biniciogˇlu-Shumovski inequality and spatially separated correlations violating the Clauser-Horne-Shimony-Holt inequality. The violation of one inequality forbids the violation of the other. We also obtain the corresponding monogamy relation imposed by quantum theory for a qutrit-qubit system. Our results show the existence of fundamental monogamy relations between contextuality and nonlocality that suggest that entanglement might be a particular form of a more fundamental resource. PMID:24679270

  12. Relativistic three-partite non-locality

    NASA Astrophysics Data System (ADS)

    Moradpour, Hooman; Montakhab, Afshin

    2016-05-01

    Bell-like inequalities have been used in order to distinguish non-local quantum pure states by various authors. The behavior of such inequalities under Lorentz transformation (LT) has been a source of debate and controversies in the past. In this paper, we consider the two most commonly studied three-particle pure states, that of W and Greenberger-Horne-Zeilinger (GHZ) states which exhibit distinctly different types of entanglement. We discuss the various types of three-particle inequalities used in previous studies and point to their corresponding shortcomings and strengths. Our main result is that if one uses Czachor’s relativistic spin operator and Svetlichny’s inequality as the main measure of non-locality and uses the same angles in the rest frame (S) as well as the moving frame (S‧), then maximally violated inequality in S will decrease in the moving frame, and will eventually lead to lack of non-locality (i.e. satisfaction of inequality) in the v→c limit. This is shown for both the GHZ and W states and in two different configurations which are commonly studied (Cases 1 and 2). Our results are in line with a more familiar case of two particle case. We also show that the satisfaction of Svetlichny’s inequality in the v→c limit is independent of initial particles’ velocity. Our study shows that whenever we use Czachor’s relativistic spin operator, results draws a clear picture of three-particle non-locality making its general properties consistent with previous studies on two-particle systems regardless of the W state or the GHZ state is involved. Throughout the paper, we also address the results of using Pauli’s operator in investigating the behavior of |Sv| under LT for both of the GHZ and W states and two cases (Cases 1 and 2). Our investigation shows that the violation of |Sv| in moving frame depends on the particle’s energy in the lab frame, which is in agreement with some previous works on two and three-particle systems. Our work may

  13. Entanglement swapping for generalized nonlocal correlations

    SciTech Connect

    Short, A. J.; Popescu, S.; Gisin, N.

    2006-01-15

    We consider an analog of entanglement-swapping for a set of black boxes with the most general nonlocal correlations consistent with relativity (including correlations which are stronger than any attainable in quantum theory). In an attempt to incorporate this phenomenon, we consider expanding the space of objects to include not only correlated boxes, but 'couplers', which are an analog for boxes of measurements with entangled eigenstates in quantum theory. Surprisingly, we find that no couplers exist for two binary-input-binary-output boxes, and hence that there is no analog of entanglement swapping for such boxes.

  14. Fundamental Monogamy Relation between Contextuality and Nonlocality

    NASA Astrophysics Data System (ADS)

    Kurzyński, Paweł; Cabello, Adán; Kaszlikowski, Dagomir

    2014-03-01

    We show that the no-disturbance principle imposes a tradeoff between locally contextual correlations violating the Klyachko-Can-Binicioǧlu-Shumovski inequality and spatially separated correlations violating the Clauser-Horne-Shimony-Holt inequality. The violation of one inequality forbids the violation of the other. We also obtain the corresponding monogamy relation imposed by quantum theory for a qutrit-qubit system. Our results show the existence of fundamental monogamy relations between contextuality and nonlocality that suggest that entanglement might be a particular form of a more fundamental resource.

  15. Lattice Gas Model with Nonlocal Interactions

    NASA Astrophysics Data System (ADS)

    Das, Shankar P.

    We analyze the nature of the hydrodynamic modes in a Lattice Gas Automata (LGA) model defined on a hexagonal lattice and having nonlocal interactions of attractive and repulsive type simultaneously. The model is similar in spirit to the liquid gas model of Appert and Zaleski [Phys. Rev. Lett. 64, 1 (1990)]. The phase diagram for the model is computed using the kinetic pressure. The dynamics is studied with a mean field type approach in the Boltzmann approximation ignoring effects of correlated collisions. We compute the transport coefficients and the speed of sound propagation. The presence of attractive interactions show increase in the transport coefficients at intermediate densities.

  16. Resonance frequency and mass identification of zeptogram-scale nanosensor based on the nonlocal beam theory.

    PubMed

    Li, Xian-Fang; Tang, Guo-Jin; Shen, Zhi-Bin; Lee, Kang Yong

    2015-01-01

    Free vibration and mass detection of carbon nanotube-based sensors are studied in this paper. Since the mechanical properties of carbon nanotubes possess a size effect, the nonlocal beam model is used to characterize flexural vibration of nanosensors carrying a concentrated nanoparticle, where the size effect is reflected by a nonlocal parameter. For nanocantilever or bridged sensor, frequency equations are derived when a nanoparticle is carried at the free end or the middle, respectively. Exact resonance frequencies are numerically determined for clamped-free, simply-supported, and clamped-clamped resonators. Alternative approximations of fundamental frequency are given in closed form within the relative error less than 0.4%, 0.6%, and 1.4% for cantilever, simply-supported, and bridged sensors, respectively. Mass identification formulae are derived in terms of the frequency shift. Identified masses via the present approach coincide with those using the molecular mechanics approach and reach as low as 10(-24)kg. The obtained results indicate that the nonlocal effect decreases the resonance frequency except for the fundamental frequency of nanocantilever sensor. These results are helpful to the design of micro/nanomechanical zeptogram-scale biosensor. PMID:25149195

  17. Buckling analysis of functionally graded nanobeams based on a nonlocal third-order shear deformation theory

    NASA Astrophysics Data System (ADS)

    Rahmani, O.; Jandaghian, A. A.

    2015-06-01

    In this paper, a general third-order beam theory that accounts for nanostructure-dependent size effects and two-constituent material variation through the nanobeam thickness, i.e., functionally graded material (FGM) beam is presented. The material properties of FG nanobeams are assumed to vary through the thickness according to the power law. A detailed derivation of the equations of motion based on Eringen nonlocal theory using Hamilton's principle is presented, and a closed-form solution is derived for buckling behavior of the new model with various boundary conditions. The nonlocal elasticity theory includes a material length scale parameter that can capture the size effect in a functionally graded material. The proposed model is efficient in predicting the shear effect in FG nanobeams by applying third-order shear deformation theory. The proposed approach is validated by comparing the obtained results with benchmark results available in the literature. In the following, a parametric study is conducted to investigate the influences of the length scale parameter, gradient index, and length-to-thickness ratio on the buckling of FG nanobeams and the improvement on nonlocal third-order shear deformation theory comparing with the classical (local) beam model has been shown. It is found out that length scale parameter is crucial in studying the stability behavior of the nanobeams.

  18. A non-local model of fractional heat conduction in rigid bodies

    NASA Astrophysics Data System (ADS)

    Borino, G.; di Paola, M.; Zingales, M.

    2011-03-01

    In recent years several applications of fractional differential calculus have been proposed in physics, chemistry as well as in engineering fields. Fractional order integrals and derivatives extend the well-known definitions of integer-order primitives and derivatives of the ordinary differential calculus to real-order operators. Engineering applications of fractional operators spread from viscoelastic models, stochastic dynamics as well as with thermoelasticity. In this latter field one of the main actractives of fractional operators is their capability to interpolate between the heat flux and its time-rate of change, that is related to the well-known second sound effect. In other recent studies a fractional, non-local thermoelastic model has been proposed as a particular case of the non-local, integral, thermoelasticity introduced at the mid of the seventies. In this study the autors aim to introduce a different non-local model of extended irreverible thermodynamics to account for second sound effect. Long-range heat flux is defined and it involves the integral part of the spatial Marchaud fractional derivatives of the temperature field whereas the second-sound effect is accounted for introducing time-derivative of the heat flux in the transport equation. It is shown that the proposed model does not suffer of the pathological problems of non-homogenoeus boundary conditions. Moreover the proposed model coalesces with the Povstenko fractional models in unbounded domains.

  19. Non-local magnetoelectric effects via Coulomb interaction in TI-FMI heterostructures

    NASA Astrophysics Data System (ADS)

    Rex, Stefan; Nogueira, Flavio S.; Sudbø, Asle

    Magnetic order on the surface of a 3 D topological insulator (TI) has been predicted to evoke a topological magnetoelectric effect (TME) by the breaking of time-reversal invariance. In the TME, an electric field leads to a magnetic polarization in the same direction as the field and vice versa. Here, we consider heterostructures of TI and ferromagnetic insulator (FMI) layers. We show that in the presence of long-range Coulomb interactions the magnetization couples non-locally to the fluctuating electric field (non-local TME) by performing a field-theoretic calculation of the vacuum polarization. In addition, we obtain a Landau-Lifshitz equation for the magnetization dynamics, and find that charged magnetic textures lead to a net magnetization even at a large distance. Such textures can be induced by an external electric field with nonzero in-plane divergence. We apply this effect to a FMI-TI-FMI trilayer heterostructure with two parallel interfaces being well-separated by the bulk TI, where we propose to non-locally control the magnetic texture at one interface by proper gating of the other interface. A preprint can be found at arXiv:1510.04285 Supported by the Norwegian Research Council, Grants 205591/V20 and 216700/F20, and the Collaborative Research Center SFB 1143 ''Correlated Magnetism: From Frustration to Topology''.

  20. The structure of common-envelope remnants

    NASA Astrophysics Data System (ADS)

    Hall, Philip D.

    2015-05-01

    We investigate the structure and evolution of the remnants of common-envelope evolution in binary star systems. In a common-envelope phase, two stars become engulfed in a gaseous envelope and, under the influence of drag forces, spiral to smaller separations. They may merge to form a single star or the envelope may be ejected to leave the stars in a shorter period orbit. This process explains the short orbital periods of many observed binary systems, such as cataclysmic variables and low-mass X-ray binary systems. Despite the importance of these systems, and of common-envelope evolution to their formation, it remains poorly understood. Specifically, we are unable to confidently predict the outcome of a common-envelope phase from the properties at its onset. After presenting a review of work on stellar evolution, binary systems, common-envelope evolution and the computer programs used, we describe the results of three computational projects on common-envelope evolution. Our work specifically relates to the methods and prescriptions which are used for predicting the outcome. We use the Cambridge stellar-evolution code STARS to produce detailed models of the structure and evolution of remnants of common-envelope evolution. We compare different assumptions about the uncertain end-of-common envelope structure and envelope mass of remnants which successfully eject their common envelopes. In the first project, we use detailed remnant models to investigate whether planetary nebulae are predicted after common-envelope phases initiated by low-mass red giants. We focus on the requirement that a remnant evolves rapidly enough to photoionize the nebula and compare the predictions for different ideas about the structure at the end of a common-envelope phase. We find that planetary nebulae are possible for some prescriptions for the end-of-common envelope structure. In our second contribution, we compute a large set of single-star models and fit new formulae to the core radii of

  1. Non-local damage rheology and size effect

    NASA Astrophysics Data System (ADS)

    Lyakhovsky, V.

    2011-12-01

    We study scaling relations controlling the onset of transiently-accelerating fracturing and transition to dynamic rupture propagation in a non-local damage rheology model. The size effect is caused principally by growth of a fracture process zone, involving stress redistribution and energy release associated with a large fracture. This implies that rupture nucleation and transition to dynamic propagation are inherently scale-dependent processes. Linear elastic fracture mechanics (LEFM) and local damage mechanics are formulated in terms of dimensionless strain components and thus do not allow introducing any space scaling, except linear relations between fracture length and displacements. Generalization of Weibull theory provides scaling relations between stress and crack length at the onset of failure. A powerful extension of the LEFM formulation is the displacement-weakening model which postulates that yielding is complete when the crack wall displacement exceeds some critical value or slip-weakening distance Dc at which a transition to kinetic friction is complete. Scaling relations controlling the transition to dynamic rupture propagation in slip-weakening formulation are widely accepted in earthquake physics. Strong micro-crack interaction in a process zone may be accounted for by adopting either integral or gradient type non-local damage models. We formulate a gradient-type model with free energy depending on the scalar damage parameter and its spatial derivative. The damage-gradient term leads to structural stresses in the constitutive stress-strain relations and a damage diffusion term in the kinetic equation for damage evolution. The damage diffusion eliminates the singular localization predicted by local models. The finite width of the localization zone provides a fundamental length scale that allows numerical simulations with the model to achieve the continuum limit. A diffusive term in the damage evolution gives rise to additional damage diffusive time

  2. Implementing a Nonlocal Toffoli Gate Using Partially Entangled Qubit Pairs

    NASA Astrophysics Data System (ADS)

    Chen, Li-Bing; Lu, Hong

    2011-11-01

    We investigate the local implementation of a nonlocal quantum Toffoli gate via partially entangled states. Firstly, we show how the nonlocal Toffoli gate can be implemented with unit fidelity and a certain probability by employing two partially entangled qubit pairs as quantum channels. The quantum circuit that does this proposed implementation is built entirely of local single-level and two-level gates if the target node harness a three-level qudit as a catalyser. This enables the construction of this key nonlocal quantum gate with existing technology. Then, we put forward a scheme to realize deterministic and exact implementation of this nonlocal gate via more partially entangled pairs. In this scheme, the control nodes' local positive operator valued measurements (POVMs) lies at the heart. We construct the required POVMs. The fact that the deterministic and exact implementation of a nonlocal multi-qubit gate could be realized by using partially entangled qubit pairs and comparatively fewer resources cost is notable.

  3. Nonlocal electrodynamics of Josephson vortices in superconducting circuits

    NASA Astrophysics Data System (ADS)

    Abdumalikov, A. A., Jr.; Alfimov, G. L.; Malishevskii, A. S.

    2009-02-01

    A review of the main analytical, numerical and experimental results of nonlocal Josephson electrodynamics in different types of junctions is presented. Several mechanisms of nonlocality are discussed. Linear electromagnetic waves and vortices (kinks) propagating along junctions are examined in detail. The main attention is paid to bulk junctions with internal nonlocality and to narrow junctions with geometrical nonlocality. Theoretical conceptions of Cherenkov excitation of plasma waves, discretization of kink velocities and forming of multikinks by binding of elementary vortices are considered. Experimental results for narrow junctions are surveyed. It is shown that the positions of Fiske steps and Cherenkov resonances at current-voltage characteristics which have been obtained in experiments can be properly explained by a nonlocal model that takes into account stray magnetic fields outside the junction.

  4. Hierarchy of multipartite nonlocality in the nonsignaling scenario

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoxu; Zhang, Chengjie; Chen, Qing; Yu, Sixia; Yuan, Haidong; Oh, C. H.

    2016-08-01

    We propose a hierarchy of Bell-type inequalities for arbitrary n -partite systems that identifies the different degrees of nonlocality ranging from standard to genuine multipartite nonlocality. After introducing the definition of nonsignaling m locality, we show that the observed joint probabilities in any nonsignaling m -local realistic models should satisfy the (m -1 )th Bell-type inequality. When m =2 , the corresponding inequality reduces to the one shown earlier [Q. Chen et al., Phys. Rev. Lett. 112, 140404 (2014), 10.1103/PhysRevLett.112.140404] whose violation indicates genuine multipartite nonlocality, and when m =n , the corresponding inequality is just Hardy's inequality whose violation indicates standard multipartite nonlocality. Furthermore, several examples are provided to demonstrate their hierarchy of multipartite nonlocality.

  5. Origin and effect of nonlocality in a layered composite.

    SciTech Connect

    Silling, Stewart Andrew

    2014-01-01

    A simple demonstration of nonlocality in a heterogeneous material is presented. By analysis of the microscale deformation of a two-component layered medium, it is shown that nonlocal interactions necessarily appear in a homogenized model of the system. Explicit expressions for the nonlocal forces are determined. The way these nonlocal forces appear in various nonlocal elasticity theories is derived. The length scales that emerge involve the constituent material properties as well as their geometrical dimen- sions. A peridynamic material model for the smoothed displacement eld is derived. It is demonstrated by comparison with experimental data that the incorporation of non- locality in modeling dramatically improves the prediction of the stress concentration in an open hole tension test on a composite plate.

  6. Energy driven pattern formation in a non-local Cahn-Hilliard energy

    NASA Astrophysics Data System (ADS)

    Goldman, Dorian

    We study the asymptotic behavior of the Ohta-Kawasaki energy in dimension 2. In that model, two phases appear, and they interact via a nonlocal Coulomb type energy. We focus on the regime where one of the phases has very small volume fraction, thus creating "droplets" of that phase in a sea of the other phase. We compute the Gamma-limit of the leading order energy and yield averaged information for almost minimizers, namely that the density of droplets should be uniform and almost spherical. We then derive a next order Gamma-limit energy determines which the geoemtric arrangement of the droplets. Without appealing at all to the Euler-Lagrange equation, we establish here for all configurations which have "almost minimal energy," the asymptotic roundness and radius of the droplets, and the fact that they asymptotically shrink to points whose arrangement should minimize this energy, in some averaged sense. This leads to expecting to see hexagonal lattices of droplets. In addition, we prove that the density of droplets of non-minimizing critical points of the energy is also uniform and that droplets are spherical in some averaged sense. Next we study a non-local isoperimetric problem in mathbb{R}2 and mathbb{T}2. We are able to show that the connectedcritical points are determined by perimeter alone, under mild assumptions on the boundary, in the small energy/mass regime. These results differ from the recent results of Julin and Muratov-Knupfer in that they concern general critical points rather than global minimizers to the energy. Our method demonstrates that not only does the perimeter dominate the non-locality when minimizing, but also that the change in perimeter slaves to the change of the non-local term in this scaling regime.

  7. Infrared image denoising by nonlocal means filtering

    NASA Astrophysics Data System (ADS)

    Dee-Noor, Barak; Stern, Adrian; Yitzhaky, Yitzhak; Kopeika, Natan

    2012-05-01

    The recently introduced non-local means (NLM) image denoising technique broke the traditional paradigm according to which image pixels are processed by their surroundings. Non-local means technique was demonstrated to outperform state-of-the art denoising techniques when applied to images in the visible. This technique is even more powerful when applied to low contrast images, which makes it tractable for denoising infrared (IR) images. In this work we investigate the performance of NLM applied to infrared images. We also present a new technique designed to speed-up the NLM filtering process. The main drawback of the NLM is the large computational time required by the process of searching similar patches. Several techniques were developed during the last years to reduce the computational burden. Here we present a new techniques designed to reduce computational cost and sustain optimal filtering results of NLM technique. We show that the new technique, which we call Multi-Resolution Search NLM (MRS-NLM), reduces significantly the computational cost of the filtering process and we present a study of its performance on IR images.

  8. Isolating The Building Thermal Envelope

    NASA Astrophysics Data System (ADS)

    Harrje, D. T.; Dutt, G. S.; Gadsby, K. J.

    1981-01-01

    The evaluation of the thermal integrity of building envelopes by infrared scanning tech-niques is often hampered in mild weather because temperature differentials across the envelope are small. Combining the infrared scanning with positive or negative building pressures, induced by a "blower door" or the building ventilation system, considerably extends the periods during which meaningful diagnostics can be conducted. Although missing or poorly installed insulation may lead to a substantial energy penalty, it is the search for air leakage sites that often has the largest potential for energy savings. Infrared inspection of the attic floor with air forced from the occupied space through ceiling by-passes, and inspecting the interior of the building when outside air is being sucked through the envelope reveals unexpected leakage sites. Portability of the diagnostic equipment is essential in these surveys which may include access into some tight spaces. A catalog of bypass heat losses that have been detected in residential housing using the combined infrared pressure differential technique is included to point out the wide variety of leakage sites which may compromise the benefits of thermal insulation and allow excessive air infiltration. Detection and suppression of such leaks should be key items in any building energy audit program. Where a calibrated blower door is used to pressurize or evacuate the house, the leakage rate can be quantified and an excessively tight house recognized. Houses that are too tight may be improved with a minimal energy penalty by forced ventilation,preferably with a heat recuperator and/or by providing combustion air directly to the furnace.

  9. Nonlocal systems of balance laws in several space dimensions with applications to laser technology

    NASA Astrophysics Data System (ADS)

    Colombo, Rinaldo M.; Marcellini, Francesca

    2015-12-01

    For a class of systems of nonlinear and nonlocal balance laws in several space dimensions, we prove the local in time existence of solutions and their continuous dependence on the initial datum. The choice of this class is motivated by a new model devoted to the description of a metal plate being cut by a laser beam. Using realistic parameters, solutions to this model obtained through numerical integrations meet qualitative properties of real cuts. Moreover, the class of equations considered comprises a model describing the dynamics of solid particles along a conveyor belt.

  10. Non-local susceptibility of the wire medium in the spatial domain considering material boundaries

    NASA Astrophysics Data System (ADS)

    Hanson, George W.; Silveirinha, Mário G.; Burghignoli, Paolo; Yakovlev, Alexander B.

    2013-08-01

    We show that the non-local susceptibility \\bar{\\boldsymbol{\\chi}}\\left (\\mathbf{r},\\mathbf{r}^{\\prime }\\right ) for a non-translationally invariant homogenized wire medium is, modulo a constant, given by a simple Green function related to the material geometry. We also show that two previous methods for solving wave interaction problems for bounded wire media (wave expansion method and transport equation) are equivalent to each other, and to a third method involving particle reflection at the boundary. We discuss the importance of the dead layer or virtual interface, and find it to be analogous to the excitonic semiconductor case. Several examples are provided to clarify the material.

  11. Determine the critical fermion flavor in three-dimensional QED using nonlocal gauge

    NASA Astrophysics Data System (ADS)

    Jiang, Hua; Wang, Yong-Long; Lu, Wei-Tao; Wang, Chuan-Cong

    2014-10-01

    We determine the critical fermion flavor for dynamical chiral symmetry breaking in three-dimensional quantum electrodynamics using nonlocal gauge (gauge parameter depends on the momentum or coordinate). The coupled Dyson-Schwinger equations of the fermion and gauge boson propagators are considered in the vicinity of the critical point. Illustrated by using the transverse vertex proposed by Bashir et al., we show that: for a variety of the transverse vertex, the critical flavor is still 128/3π2, the same as using the bare vertex.

  12. Motion of soliton center of interactional solitons in nonlinear media with an exponential nonlocal response

    NASA Astrophysics Data System (ADS)

    Dai, Zhiping; Yang, Zhenjun; Ling, Xiaohui; Zhang, Shumin; Pang, Zhaoguang; Li, Jianxing

    2016-05-01

    The motion of two interactional solitons is investigated in nonlinear media with an exponential nonlocal response. A differential equation describing the motion trajectories of soliton center is proposed. Some numerical simulations are performed to illustrate the characteristics of the motion trajectories. The results show that the trajectories always oscillate periodically. However, if the two solitons are launched with a relative inclined angle which is larger than a critical value, they do not collide any more but diverge from each other. The critical angle is also given.

  13. Black supernovae and black holes in non-local gravity

    NASA Astrophysics Data System (ADS)

    Bambi, Cosimo; Malafarina, Daniele; Modesto, Leonardo

    2016-04-01

    In a previous paper, we studied the interior solution of a collapsing body in a non-local theory of gravity super-renormalizable at the quantum level. We found that the classical singularity is replaced by a bounce, after which the body starts expanding. A black hole, strictly speaking, never forms. The gravitational collapse does not create an event horizon but only an apparent one for a finite time. In this paper, we solve the equations of motion assuming that the exterior solution is static. With such an assumption, we are able to reconstruct the solution in the whole spacetime, namely in both the exterior and interior regions. Now the gravitational collapse creates an event horizon in a finite comoving time, but the central singularity is approached in an infinite time. We argue that these black holes should be unstable, providing a link between the scenarios with and without black holes. Indeed, we find a non catastrophic ghost-instability of the metric in the exterior region. Interestingly, under certain conditions, the lifetime of our black holes exactly scales as the Hawking evaporation time.

  14. Variational Principles for Buckling of Microtubules Modeled as Nonlocal Orthotropic Shells

    PubMed Central

    2014-01-01

    A variational principle for microtubules subject to a buckling load is derived by semi-inverse method. The microtubule is modeled as an orthotropic shell with the constitutive equations based on nonlocal elastic theory and the effect of filament network taken into account as an elastic surrounding. Microtubules can carry large compressive forces by virtue of the mechanical coupling between the microtubules and the surrounding elastic filament network. The equations governing the buckling of the microtubule are given by a system of three partial differential equations. The problem studied in the present work involves the derivation of the variational formulation for microtubule buckling. The Rayleigh quotient for the buckling load as well as the natural and geometric boundary conditions of the problem is obtained from this variational formulation. It is observed that the boundary conditions are coupled as a result of nonlocal formulation. It is noted that the analytic solution of the buckling problem for microtubules is usually a difficult task. The variational formulation of the problem provides the basis for a number of approximate and numerical methods of solutions and furthermore variational principles can provide physical insight into the problem. PMID:25214886

  15. Non-local wave propagation in embedded armchair TWBNNTs conveying viscous fluid using DQM

    NASA Astrophysics Data System (ADS)

    Abdollahian, M.; Ghorbanpour Arani, A.; Mosallaie Barzoki, A. A.; Kolahchi, R.; Loghman, A.

    2013-06-01

    In this study, nonlocal electro-thermo-mechanical wave propagation in an embedded armchair three-walled boron nitride nanotube (TWBNNT) conveying viscous fluid under torsional load is investigated. The interaction between two adjacent layers is considered using van der Waals (vdW) forces. The surrounded elastic medium is taken into account using Winkler and Pasternak models. The energy method and Hamilton's principle are used to establish the equations of motion. Given the relationship between the piezoelectric coefficient of armchair boron nitride nanotubes (BNNTs) and stresses, the first-order shear deformation theory (FSDT) is applied to obtain the equations of motion in terms of displacements. The set of coupled governing equations of motion for the TWBNNT are then numerically solved by the differential quadrature method (DQM). The effects of small scale, fluid flow, elastic foundation and temperature on the phase velocity of TWBNNT, critical fluid velocity and critical torsional load are presented graphically. Results show the importance of applying nonlocal elasticity theory on the phase velocity of TWBNNT.

  16. Flexible Envelope Request Notation (FERN)

    NASA Technical Reports Server (NTRS)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart

    1991-01-01

    The following topics are presented in view graph form and include the following: scheduling application; the motivation for the Flexible Envelope Request Notation (FERN); characteristics of FERN; types of information needed in requests; where information is stored in requests; FERN structures; generic requests; resource availability for pooled resources; expressive notation; temporal constraints; time formats; changes to FERN; sample FERN requests; the temporal relationship between two steps; maximum activity length to limit step delays; alternative requests; the temporal relationship between two activities; and idle resource usage between steps.

  17. Homoclinic behaviors and chaotic motions of double layered viscoelastic nanoplates based on nonlocal theory and extended Melnikov method

    SciTech Connect

    Wang, Yu; Wang, Yi-Ze; Li, Feng-Ming

    2015-06-15

    The nonlinear dynamical equations are established for the double layered viscoelastic nanoplates (DLNP) subjected to in-plane excitation based on the nonlocal theory and von Kármán large deformation theory. The extended high dimensional homoclinic Melnikov method is employed to study the homoclinic phenomena and chaotic motions for the parametrically excited DLNP system. The criteria for the homoclinic transverse intersection for both the asynchronous and synchronous buckling cases are proposed. Lyapunov exponents and phase portraits are obtained to verify the Melnikov-type analysis. The influences of structural parameters on the transverse homoclinic orbits and homoclinic bifurcation sets are discussed for the two buckling cases. Some novel phenomena are observed in the investigation. It should be noticed that the nonlocal effect on the homoclinic behaviors and chaotic motions is quite remarkable. Hence, the small scale effect should be taken into account for homoclinic and chaotic analysis for nanostructures. It is significant that the nonlocal effect on the homoclinic phenomena for the asynchronous buckling case is quite different from that for the synchronous buckling case. Moreover, due to the van der Walls interaction between the layers, the nonlocal effect on the homoclinic behaviors and chaotic motions for high order mode is rather tiny under the asynchronous buckling condition.

  18. Homoclinic behaviors and chaotic motions of double layered viscoelastic nanoplates based on nonlocal theory and extended Melnikov method.

    PubMed

    Wang, Yu; Li, Feng-Ming; Wang, Yi-Ze

    2015-06-01

    The nonlinear dynamical equations are established for the double layered viscoelastic nanoplates (DLNP) subjected to in-plane excitation based on the nonlocal theory and von Kármán large deformation theory. The extended high dimensional homoclinic Melnikov method is employed to study the homoclinic phenomena and chaotic motions for the parametrically excited DLNP system. The criteria for the homoclinic transverse intersection for both the asynchronous and synchronous buckling cases are proposed. Lyapunov exponents and phase portraits are obtained to verify the Melnikov-type analysis. The influences of structural parameters on the transverse homoclinic orbits and homoclinic bifurcation sets are discussed for the two buckling cases. Some novel phenomena are observed in the investigation. It should be noticed that the nonlocal effect on the homoclinic behaviors and chaotic motions is quite remarkable. Hence, the small scale effect should be taken into account for homoclinic and chaotic analysis for nanostructures. It is significant that the nonlocal effect on the homoclinic phenomena for the asynchronous buckling case is quite different from that for the synchronous buckling case. Moreover, due to the van der Walls interaction between the layers, the nonlocal effect on the homoclinic behaviors and chaotic motions for high order mode is rather tiny under the asynchronous buckling condition. PMID:26117102

  19. Safeguards Envelope Progress FY10

    SciTech Connect

    Richard Metcalf

    2010-10-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details the additions to the advanced operating techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). Research this year focused on combining disparate pieces of data together to maximize operating time with minimal downtime due to safeguards. A Chi-Square and Croiser's cumulative sum were both included as part of the new analysis. Because of a major issue with the original data, the implementation of the two new tests did not add to the existing set of tests, though limited one-variable optimization made a small increase in detection probability. Additional analysis was performed to determine if prior analysis would have caused a major security or safety operating envelope issue. It was determined that a safety issue would have resulted from the prior research, but that the security may have been increased under certain conditions.

  20. Nonlocal Mumford-Shah regularizers for color image restoration.

    PubMed

    Jung, Miyoun; Bresson, Xavier; Chan, Tony F; Vese, Luminita A

    2011-06-01

    We propose here a class of restoration algorithms for color images, based upon the Mumford-Shah (MS) model and nonlocal image information. The Ambrosio-Tortorelli and Shah elliptic approximations are defined to work in a small local neighborhood, which are sufficient to denoise smooth regions with sharp boundaries. However, texture is nonlocal in nature and requires semilocal/non-local information for efficient image denoising and restoration. Inspired from recent works (nonlocal means of Buades, Coll, Morel, and nonlocal total variation of Gilboa, Osher), we extend the local Ambrosio-Tortorelli and Shah approximations to MS functional (MS) to novel nonlocal formulations, for better restoration of fine structures and texture. We present several applications of the proposed nonlocal MS regularizers in image processing such as color image denoising, color image deblurring in the presence of Gaussian or impulse noise, color image inpainting, color image super-resolution, and color filter array demosaicing. In all the applications, the proposed nonlocal regularizers produce superior results over the local ones, especially in image inpainting with large missing regions. We also prove several characterizations of minimizers based upon dual norm formulations. PMID:21078579

  1. Oblique modulation of ion-acoustic waves and envelope solitons in electron-positron-ion plasma

    SciTech Connect

    Jehan, Nusrat; Salahuddin, M.; Mirza, Arshad M.

    2009-06-15

    The effect of oblique modulation on the amplitude dynamics of ion-acoustic wave propagating in a collisionless electron-positron-ion plasma is investigated. Using Krylov-Bogoliubov-Mitropolsky (KBM) perturbation method, a nonlinear Schroedinger (NLS) equation is derived which governs the evolution of obliquely modulated ion-acoustic envelope excitations. It is found that the presence of positron component significantly modifies the stability domains for small angles of propagation with the direction of modulation. The stationary solutions of NLS equation, i.e., bright and dark envelope solitons, become narrower as the concentration of positron component increases.

  2. Ion-acoustic envelope modes in a degenerate relativistic electron-ion plasma

    NASA Astrophysics Data System (ADS)

    McKerr, M.; Haas, F.; Kourakis, I.

    2016-05-01

    A self-consistent relativistic two-fluid model is proposed for one-dimensional electron-ion plasma dynamics. A multiple scales perturbation technique is employed, leading to an evolution equation for the wave envelope, in the form of a nonlinear Schrödinger type equation (NLSE). The inclusion of relativistic effects is shown to introduce density-dependent factors, not present in the non-relativistic case—in the conditions for modulational instability. The role of relativistic effects on the linear dispersion laws and on envelope soliton solutions of the NLSE is discussed.

  3. Robust Maneuvering Envelope Estimation Based on Reachability Analysis in an Optimal Control Formulation

    NASA Technical Reports Server (NTRS)

    Lombaerts, Thomas; Schuet, Stefan R.; Wheeler, Kevin; Acosta, Diana; Kaneshige, John

    2013-01-01

    This paper discusses an algorithm for estimating the safe maneuvering envelope of damaged aircraft. The algorithm performs a robust reachability analysis through an optimal control formulation while making use of time scale separation and taking into account uncertainties in the aerodynamic derivatives. Starting with an optimal control formulation, the optimization problem can be rewritten as a Hamilton- Jacobi-Bellman equation. This equation can be solved by level set methods. This approach has been applied on an aircraft example involving structural airframe damage. Monte Carlo validation tests have confirmed that this approach is successful in estimating the safe maneuvering envelope for damaged aircraft.

  4. Nuclear envelope: positioning nuclei and organizing synapses

    PubMed Central

    Razafsky, David; Hodzic, Didier

    2015-01-01

    The nuclear envelope plays an essential role in nuclear positioning within cells and tissues. This review highlights advances in understanding the mechanisms of nuclear positioning during skeletal muscle and central nervous system development. New findings, particularly about Atype lamins and Nesprin1, may link nuclear envelope integrity to synaptic integrity. Thus synaptic defects, rather than nuclear mispositioning, may underlie human pathologies associated with mutations of nuclear envelope proteins. PMID:26079712

  5. Switching non-local median filter

    NASA Astrophysics Data System (ADS)

    Matsuoka, Jyohei; Koga, Takanori; Suetake, Noriaki; Uchino, Eiji

    2015-06-01

    This paper describes a novel image filtering method for removal of random-valued impulse noise superimposed on grayscale images. Generally, it is well known that switching-type median filters are effective for impulse noise removal. In this paper, we propose a more sophisticated switching-type impulse noise removal method in terms of detail-preserving performance. Specifically, the noise detector of the proposed method finds out noise-corrupted pixels by focusing attention on the difference between the value of a pixel of interest (POI) and the median of its neighboring pixel values, and on the POI's isolation tendency from the surrounding pixels. Furthermore, the removal of the detected noise is performed by the newly proposed median filter based on non-local processing, which has superior detail-preservation capability compared to the conventional median filter. The effectiveness and the validity of the proposed method are verified by some experiments using natural grayscale images.

  6. Nonlocal means denoising of ECG signals.

    PubMed

    Tracey, Brian H; Miller, Eric L

    2012-09-01

    Patch-based methods have attracted significant attention in recent years within the field of image processing for a variety of problems including denoising, inpainting, and super-resolution interpolation. Despite their prevalence for processing 2-D signals, they have received little attention in the 1-D signal processing literature. In this letter, we explore application of one such method, the nonlocal means (NLM) approach, to the denoising of biomedical signals. Using ECG as an example, we demonstrate that a straightforward NLM-based denoising scheme provides signal-to-noise ratio improvements very similar to state of the art wavelet-based methods, while giving ~3 × or greater reduction in metrics measuring distortion of the denoised waveform. PMID:22829361

  7. Single-electron entanglement and nonlocality

    NASA Astrophysics Data System (ADS)

    Dasenbrook, David; Bowles, Joseph; Bohr Brask, Jonatan; Hofer, Patrick P.; Flindt, Christian; Brunner, Nicolas

    2016-04-01

    Motivated by recent progress in electron quantum optics, we revisit the question of single-electron entanglement, specifically whether the state of a single electron in a superposition of two separate spatial modes should be considered entangled. We first discuss a gedanken experiment with single-electron sources and detectors, and demonstrate deterministic (i. e. without post-selection) Bell inequality violation. This implies that the single-electron state is indeed entangled and, furthermore, nonlocal. We then present an experimental scheme where single-electron entanglement can be observed via measurements of the average currents and zero-frequency current cross-correlators in an electronic Hanbury Brown–Twiss interferometer driven by Lorentzian voltage pulses. We show that single-electron entanglement is detectable under realistic operating conditions. Our work settles the question of single-electron entanglement and opens promising perspectives for future experiments.

  8. A nonlocal spatial model for Lyme disease

    NASA Astrophysics Data System (ADS)

    Yu, Xiao; Zhao, Xiao-Qiang

    2016-07-01

    This paper is devoted to the study of a nonlocal and time-delayed reaction-diffusion model for Lyme disease with a spatially heterogeneous structure. In the case of a bounded domain, we first prove the existence of the positive steady state and a threshold type result for the disease-free system, and then establish the global dynamics for the model system in terms of the basic reproduction number. In the case of an unbound domain, we obtain the existence of the disease spreading speed and its coincidence with the minimal wave speed. At last, we use numerical simulations to verify our analytic results and investigate the influence of model parameters and spatial heterogeneity on the disease infection risk.

  9. Nonlocal kinetic-energy-density functionals

    SciTech Connect

    Garcia-Gonzalez, P.; Alvarellos, J.E.; Chacon, E. |

    1996-04-01

    In this paper we present nonlocal kinetic-energy functionals {ital T}[{ital n}] within the average density approximation (ADA) framework, which do not require any extra input when applied to any electron system and recover the exact kinetic energy and the linear response function of a homogeneous system. In contrast with previous ADA functionals, these present good behavior of the long-range tail of the exact weight function. The averaging procedure for the kinetic functional (averaging the Fermi momentum of the electron gas, instead of averaging the electron density) leads to a functional without numerical difficulties in the calculation of extended systems, and it gives excellent results when applied to atoms and jellium surfaces. {copyright} {ital 1996 The American Physical Society.}

  10. Nonlocal Constitutive Relation for Steady Granular Flow

    NASA Astrophysics Data System (ADS)

    Kamrin, Ken; Koval, Georg

    2012-04-01

    Extending recent modeling efforts for emulsions, we propose a nonlocal fluidity relation for flowing granular materials, capturing several known finite-size effects observed in steady flow. We express the local Bagnold-type granular flow law in terms of a fluidity ratio and then extend it with a particular Laplacian term that is scaled by the grain size. The resulting model is calibrated against a sequence of existing discrete element method data sets for two-dimensional annular shear, where it is shown that the model correctly describes the divergence from a local rheology due to the grain size as well as the rate-independence phenomenon commonly observed in slowly flowing zones. The same law is then applied in two additional inhomogeneous flow geometries, and the predicted velocity profiles are compared against corresponding discrete element method simulations utilizing the same grain composition as before, yielding favorable agreement in each case.

  11. Inverse scattering transform for the time dependent Schrödinger equation with applications to the KPI equation

    NASA Astrophysics Data System (ADS)

    Zhou, Xin

    1990-03-01

    For the direct-inverse scattering transform of the time dependent Schrödinger equation, rigorous results are obtained based on an opertor-triangular-factorization approach. By viewing the equation as a first order operator equation, similar results as for the first order n x n matrix system are obtained. The nonlocal Riemann-Hilbert problem for inverse scattering is shown to have solution.

  12. Origins of nonlocality near the neutrality point in graphene.

    PubMed

    Renard, Julien; Studer, Matthias; Folk, Joshua A

    2014-03-21

    We present an experimental study of nonlocal electrical signals near the Dirac point in graphene. The in-plane magnetic field dependence of the nonlocal signal confirms the role of spin in this effect, as expected from recent predictions of the Zeeman spin Hall effect in graphene, but our experiments show that thermo-magneto-electric effects also contribute to nonlocality, and the effect is sometimes stronger than that due to spin. Thermal effects are seen to be very sensitive to sample details that do not influence other transport parameters. PMID:24702396

  13. Quantitative relations between measurement incompatibility, quantum steering, and nonlocality

    NASA Astrophysics Data System (ADS)

    Cavalcanti, D.; Skrzypczyk, P.

    2016-05-01

    The certification of Bell nonlocality or quantum steering implies the use of incompatible measurements. Here we make this connection quantitative. We show how to strengthen robustness-based steering and nonlocality quantifiers in order that they give strong lower bounds to previously proposed incompatibility quantifiers. Our results can be seen from two perspectives. On the one hand, they can be used to estimate how much steering or nonlocality can be demonstrated with a given set of measurements. On the other hand, they give one-sided device-independent and device-independent ways of estimating measurement incompatibility.

  14. Large nonlocal nonlinear optical response of castor oil

    NASA Astrophysics Data System (ADS)

    Souza, Rogério F.; Alencar, Márcio A. R. C.; Meneghetti, Mario R.; Hickmann, Jandir M.

    2009-09-01

    The nonlocal nonlinearity of castor oil was investigated using the Z-scan technique in the CW regime at 514 nm and in femtosecond regime at 810 nm. Large negative nonlinear refractive indexes of thermal origin, thermo-optical coefficients and degree of nonlocality were obtained for both laser excitation wavelengths. The results indicate that the electronic part of the nonlinear refractive index and nonlinear absorption were negligible. Our results suggest that castor oil is promising candidate as a nonlinear medium for several nonlocal optical applications, such as in spatial soliton propagation, as well as a dispersant agent in the measurement of absorptive properties of nanoparticles.

  15. Critical point analysis of phase envelope diagram

    SciTech Connect

    Soetikno, Darmadi; Siagian, Ucok W. R.; Kusdiantara, Rudy Puspita, Dila Sidarto, Kuntjoro A. Soewono, Edy; Gunawan, Agus Y.

    2014-03-24

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  16. Critical point analysis of phase envelope diagram

    NASA Astrophysics Data System (ADS)

    Soetikno, Darmadi; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Siagian, Ucok W. R.; Soewono, Edy; Gunawan, Agus Y.

    2014-03-01

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  17. Nonlinear structure formation in nonlocal gravity

    SciTech Connect

    Barreira, Alexandre; Li, Baojiu; Hellwing, Wojciech A.; Baugh, Carlton M.; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: c.m.baugh@durham.ac.uk

    2014-09-01

    We study the nonlinear growth of structure in nonlocal gravity models with the aid of N-body simulation and the spherical collapse and halo models. We focus on a model in which the inverse-squared of the d'Alembertian operator acts on the Ricci scalar in the action. For fixed cosmological parameters, this model differs from ΛCDM by having a lower late-time expansion rate and an enhanced and time-dependent gravitational strength ∼ 6% larger today). Compared to ΛCDM today, in the nonlocal model, massive haloes are slightly more abundant (by ∼ 10% at M ∼ 10{sup 14} M{sub ⊙}/h) and concentrated ≈ 8% enhancement over a range of mass scales), but their linear bias remains almost unchanged. We find that the Sheth-Tormen formalism describes the mass function and halo bias very well, with little need for recalibration of free parameters. The fitting of the halo concentrations is however essential to ensure the good performance of the halo model on small scales. For k ∼> 1 h/Mpc, the amplitude of the nonlinear matter and velocity divergence power spectra exhibits a modest enhancement of ∼ 12% to 15%, compared to ΛCDM today. This suggests that this model might only be distinguishable from ΛCDM by future observational missions. We point out that the absence of a screening mechanism may lead to tensions with Solar System tests due to local time variations of the gravitational strength, although this is subject to assumptions about the local time evolution of background averaged quantities.

  18. A Combinatorial Approach to Nonlocality and Contextuality

    NASA Astrophysics Data System (ADS)

    Acín, Antonio; Fritz, Tobias; Leverrier, Anthony; Sainz, Ana Belén

    2015-03-01

    So far, most of the literature on (quantum) contextuality and the Kochen-Specker theorem seems either to concern particular examples of contextuality, or be considered as quantum logic. Here, we develop a general formalism for contextuality scenarios based on the combinatorics of hypergraphs, which significantly refines a similar recent approach by Cabello, Severini and Winter (CSW). In contrast to CSW, we explicitly include the normalization of probabilities, which gives us a much finer control over the various sets of probabilistic models like classical, quantum and generalized probabilistic. In particular, our framework specializes to (quantum) nonlocality in the case of Bell scenarios, which arise very naturally from a certain product of contextuality scenarios due to Foulis and Randall. In the spirit of CSW, we find close relationships to several graph invariants. The recently proposed Local Orthogonality principle turns out to be a special case of a general principle for contextuality scenarios related to the Shannon capacity of graphs. Our results imply that it is strictly dominated by a low level of the Navascués-Pironio-Acín hierarchy of semidefinite programs, which we also apply to contextuality scenarios. We derive a wealth of results in our framework, many of these relating to quantum and supraquantum contextuality and nonlocality, and state numerous open problems. For example, we show that the set of quantum models on a contextuality scenario can in general not be characterized in terms of a graph invariant. In terms of graph theory, our main result is this: there exist two graphs and with the properties

  19. Calculating nonlocal optical properties of structures with arbitrary shape.

    SciTech Connect

    McMahon, J. M.; Gray, S. K.; Schatz, G. C.; Northwestern Univ.

    2010-07-16

    In a recent Letter [J. M. McMahon, S. K. Gray, and G. C. Schatz, Phys. Rev. Lett. 103, 097403 (2009)], we outlined a computational method to calculate the optical properties of structures with a spatially nonlocal dielectric function. In this paper, we detail the full method and verify it against analytical results for cylindrical nanowires. Then, as examples of our method, we calculate the optical properties of Au nanostructures in one, two, and three dimensions. We first calculate the transmission, reflection, and absorption spectra of thin films. Because of their simplicity, these systems demonstrate clearly the longitudinal (or volume) plasmons characteristic of nonlocal effects, which result in anomalous absorption and plasmon blueshifting. We then study the optical properties of spherical nanoparticles, which also exhibit such nonlocal effects. Finally, we compare the maximum and average electric field enhancements around nanowires of various shapes to local theory predictions. We demonstrate that when nonlocal effects are included, significant decreases in such properties can occur.

  20. Popescu-Rohrlich correlations imply efficient instantaneous nonlocal quantum computation

    NASA Astrophysics Data System (ADS)

    Broadbent, Anne

    2016-08-01

    In instantaneous nonlocal quantum computation, two parties cooperate in order to perform a quantum computation on their joint inputs, while being restricted to a single round of simultaneous communication. Previous results showed that instantaneous nonlocal quantum computation is possible, at the cost of an exponential amount of prior shared entanglement (in the size of the input). Here, we show that a linear amount of entanglement suffices, (in the size of the computation), as long as the parties share nonlocal correlations as given by the Popescu-Rohrlich box. This means that communication is not required for efficient instantaneous nonlocal quantum computation. Exploiting the well-known relation to position-based cryptography, our result also implies the impossibility of secure position-based cryptography against adversaries with nonsignaling correlations. Furthermore, our construction establishes a quantum analog of the classical communication complexity collapse under nonsignaling correlations.

  1. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures

    NASA Astrophysics Data System (ADS)

    Krasavin, A. V.; Ginzburg, P.; Wurtz, G. A.; Zayats, A. V.

    2016-05-01

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response.

  2. Nonlocal microscopic theory of quantum friction between parallel metallic slabs

    SciTech Connect

    Despoja, Vito

    2011-05-15

    We present a new derivation of the friction force between two metallic slabs moving with constant relative parallel velocity, based on T=0 quantum-field theory formalism. By including a fully nonlocal description of dynamically screened electron fluctuations in the slab, and avoiding the usual matching-condition procedure, we generalize previous expressions for the friction force, to which our results reduce in the local limit. Analyzing the friction force calculated in the two local models and in the nonlocal theory, we show that for physically relevant velocities local theories using the plasmon and Drude models of dielectric response are inappropriate to describe friction, which is due to excitation of low-energy electron-hole pairs, which are properly included in nonlocal theory. We also show that inclusion of dissipation in the nonlocal electronic response has negligible influence on friction.

  3. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures

    PubMed Central

    Krasavin, A. V.; Ginzburg, P.; Wurtz, G. A.; Zayats, A. V.

    2016-01-01

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response. PMID:27157982

  4. Nonlocality-driven supercontinuum white light generation in plasmonic nanostructures.

    PubMed

    Krasavin, A V; Ginzburg, P; Wurtz, G A; Zayats, A V

    2016-01-01

    Structured plasmonic metals are widely employed for achieving nonlinear functionalities at the nanoscale due to their ability to confine and enhance electromagnetic fields and strong, inherent nonlinearity. Optical nonlinearities in centrosymmetric metals are dominated by conduction electron dynamics, which at the nanoscale can be significantly affected by the nonlocal effects. Here we show that nonlocal corrections, being usually small in the linear optical response, define nonlinear properties of plasmonic nanostructures. Using a full non-perturbative time-domain hydrodynamic description of electron plasma under femtosecond excitation, we numerically investigate harmonic generation in metallic Archimedean nanospirals, revealing the interplay between geometric and nonlocal effects. The quantum pressure term in the nonlinear hydrodynamic model results in the emergence of fractional nonlinear harmonics leading to broadband coherent white-light generation. The described effects present a novel class of nonlinear phenomena in metallic nanostructures determined by nonlocality of the electron response. PMID:27157982

  5. Quantum nonlocality via local contextuality with qubit-qubit entanglement

    NASA Astrophysics Data System (ADS)

    Saha, Debashis; Cabello, Adán; Choudhary, Sujit K.; Pawłowski, Marcin

    2016-04-01

    Quantum nonlocality can be revealed "via local contextuality" in qudit-qudit entangled systems with d >2 , that is, through the violation of inequalities containing Alice-Bob correlations that admit a local description, and Alice-Alice correlations (between the results of sequences of measurements on Alice's subsystem) that admit a local (but contextual) description. A fundamental question to understand the respective roles of entanglement and local contextuality is whether nonlocality via local contextuality exists when the parties have only qubit-qubit entanglement. Here we respond affirmatively to this question. This result further clarifies the connection between contextuality and nonlocality and opens the door for observing nonlocality via local contextuality in actual experiments.

  6. 14 CFR 23.333 - Flight envelope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight envelope. 23.333 Section 23.333... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23.333 Flight envelope. (a) General. Compliance with the strength requirements of this subpart must be shown...

  7. Non-local gyrokinetic model of linear ion-temperature-gradient modes

    SciTech Connect

    Moradi, S.; Anderson, J.

    2012-08-15

    The non-local properties of anomalous transport in fusion plasmas are still an elusive topic. In this work, a theory of non-local linear ion-temperature-gradient (ITG) drift modes while retaining non-adiabatic electrons and finite temperature gradients is presented, extending the previous work [S. Moradi et al., Phys. Plasmas 18, 062106 (2011)]. A dispersion relation is derived to quantify the effects on the eigenvalues of the unstable ion temperature gradient modes and non-adiabatic electrons on the order of the fractional velocity operator in the Fokker-Planck equation. By solving this relation for a given eigenvalue, it is shown that as the linear eigenvalues of the modes increase, the order of the fractional velocity derivative deviates from two and the resulting equilibrium probability density distribution of the plasma, i.e., the solution of the Fokker-Planck equation, deviates from a Maxwellian and becomes Levy distributed. The relative effect of the real frequency of the ITG mode on the deviation of the plasma from Maxwellian is larger than from the growth rate. As was shown previously the resulting Levy distribution of the plasma may in turn significantly alter the transport as well.

  8. Nonlocal nonlinear refraction in Hibiscus sabdariffa with large phase shifts.

    PubMed

    Ramírez-Martínez, D; Alvarado-Méndez, E; Trejo-Durán, M; Vázquez-Guevara, M A

    2014-10-20

    In this work we present a study of nonlinear optical properties in organic materials (hibiscus sabdariffa). Our results demonstrate that the medium exhibits a highly nonlocal nonlinear response. We show preliminary numerical results of the transmittance as nonlocal response by considering, simultaneously, the nonlinear absorption and refraction in media. Numerical results are accord to measurement obtained by Z- scan technique where we observe large phase shifts. We also analyze the far field diffraction ring patterns of the sample. PMID:25401548

  9. Non-local F(R)-mimetic gravity

    NASA Astrophysics Data System (ADS)

    Myrzakulov, Ratbay; Sebastiani, Lorenzo

    2016-06-01

    In this paper, we study non-local F(R)-mimetic gravity. We implement mimetic gravity in the framework of non-local F(R)-theories of gravity. Given some specific class of models and using a potential on the mimetic field, we investigate some scenarios related to the early-time universe, namely the inflation and the cosmological bounce, which bring to Einstein's gravity with cold dark matter at the late-time.

  10. Protecting quantum entanglement and nonlocality for tripartite states under decoherence

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Yin, Yu Hao; Ma, Wen Chao; Ye, Liu

    2016-06-01

    Quantum entanglement and nonlocality will suffer inevitable harm from decoherence environment. Based on GHZ state, we study the harm of the generalized amplitude damping (GAD) operation and the protection by the single local filtering (SLF) operation in this paper. We verify that the SLF functions to depress the loss of entanglement and nonlocality from GAD. This conclusion will guide us to select the best method to protect the GHZ state from GAD decoherence.

  11. Stabilization of vortex solitons in nonlocal nonlinear media

    SciTech Connect

    Minzoni, Antonmaria A.; Smyth, Noel F.; Worthy, Annette L.; Kivshar, Yuri S.

    2007-12-15

    We study the evolution of vortex solitons in optical media with a nonlocal nonlinear response. We employ a modulation theory for the vortex parameters based on an averaged Lagrangian, and analyze the azimuthal evolution of both the vortex width and diffractive radiation. We describe analytically the physical mechanism for vortex stabilization due to the long-range nonlocal nonlinear response, the effect observed earlier in numerical simulations only.

  12. From local to nonlocal Fermi liquid in doped antiferromagnets

    SciTech Connect

    Prelovsek, P. |; Jaklic, J.; Bedell, K.

    1999-07-01

    The variation of single-particle spectral functions with doping is studied numerically within the t-J model. Results suggest that the corresponding self-energies change from local ones at the intermediate doping to strongly nonlocal ones for a weakly doped antiferromagnet. The nonlocality shows up most clearly in the pseudogap emerging in the density of states, due to the onset of short-range antiferromagnetic correlations. {copyright} {ital 1999} {ital The American Physical Society}

  13. Nonlocality in pure and mixed n-qubit X states

    NASA Astrophysics Data System (ADS)

    Batle, J.; Ooi, C. H. Raymond; Farouk, Ahmed; Abdalla, S.

    2016-04-01

    Nonlocality for general multiqubit X states is studied in detail. Pure and mixed states are analyzed as far as their maximum amount of nonlocality is concerned, and analytic results are obtained for important families of these states. The particular form of nonzero diagonal and antidiagonal matrix elements makes the corresponding study easy enough to obtain exact results. We also provide a numerical recipe to randomly generate an important family of X states endowed with a given degree of mixture.

  14. Meson phenomenology and phase transitions in nonlocal chiral quark models

    NASA Astrophysics Data System (ADS)

    Carlomagno, J. P.; Gomez Dumm, D.; Pagura, V.; Scoccola, N. N.

    2015-07-01

    We study the features of nonlocal chiral quark models that include wave function renormalization. Model parameters are determined from meson phenomenology, considering different nonlocal form factor shapes. In this context we analyze the characteristics of the deconfinement and chiral restoration transitions at finite temperature and chemical potential, introducing the couplings of fermions to the Polyakov loop for different Polyakov potentials. The results for various thermodynamical quantities are compared with data obtained from lattice QCD calculations.

  15. Finite Volume schemes on unstructured grids for non-local models: Application to the simulation of heat transport in plasmas

    SciTech Connect

    Goudon, Thierry; Parisot, Martin

    2012-10-15

    In the so-called Spitzer-Haerm regime, equations of plasma physics reduce to a nonlinear parabolic equation for the electronic temperature. Coming back to the derivation of this limiting equation through hydrodynamic regime arguments, one is led to construct a hierarchy of models where the heat fluxes are defined through a non-local relation which can be reinterpreted as well by introducing coupled diffusion equations. We address the question of designing numerical methods to simulate these equations. The basic requirement for the scheme is to be asymptotically consistent with the Spitzer-Haerm regime. Furthermore, the constraints of physically realistic simulations make the use of unstructured meshes unavoidable. We develop a Finite Volume scheme, based on Vertex-Based discretization, which reaches these objectives. We discuss on numerical grounds the efficiency of the method, and the ability of the generalized models in capturing relevant phenomena missed by the asymptotic problem.

  16. Color Image Restoration Using Nonlocal Mumford-Shah Regularizers

    NASA Astrophysics Data System (ADS)

    Jung, Miyoun; Bresson, Xavier; Chan, Tony F.; Vese, Luminita A.

    We introduce several color image restoration algorithms based on the Mumford-Shah model and nonlocal image information. The standard Ambrosio-Tortorelli and Shah models are defined to work in a small local neighborhood, which are sufficient to denoise smooth regions with sharp boundaries. However, textures are not local in nature and require semi-local/non-local information to be denoised efficiently. Inspired from recent work (NL-means of Buades, Coll, Morel and NL-TV of Gilboa, Osher), we extend the standard models of Ambrosio-Tortorelli and Shah approximations to Mumford-Shah functionals to work with nonlocal information, for better restoration of fine structures and textures. We present several applications of the proposed nonlocal MS regularizers in image processing such as color image denoising, color image deblurring in the presence of Gaussian or impulse noise, color image inpainting, and color image super-resolution. In the formulation of nonlocal variational models for the image deblurring with impulse noise, we propose an efficient preprocessing step for the computation of the weight function w. In all the applications, the proposed nonlocal regularizers produce superior results over the local ones, especially in image inpainting with large missing regions. Experimental results and comparisons between the proposed nonlocal methods and the local ones are shown.

  17. Nonlocal transport in a hybrid two-dimensional topological insulator

    NASA Astrophysics Data System (ADS)

    Xing, Yanxia; Sun, Qing-feng

    2014-02-01

    We study nonlocal resistance in an H-shaped two-dimensional HgTe/CdTe quantum well consisting of an injector and a detector, both of which can be tuned in the quantum spin Hall or metallic spin Hall regime. Because of strong spin-orbit interaction, there always exists the spin Hall effect and nonlocal resistance in the HgTe/CdTe quantum well. We find that when both the detector and the injector are in the quantum spin Hall regime, the nonlocal resistance is quantized at 0.25he2, which is robust against weak disorder scattering and small magnetic field. When the detector or injector is beyond this regime, the nonlocal resistance decreases rapidly and will be strongly suppressed by disorder and magnetic field. In the presence of a strong magnetic field, the quantum spin Hall regime will be switched into the quantum Hall regime, and the nonlocal resistance will disappear. The nonlocal signal and its various manifestations in different hybrid regimes originate from the special band structure of the HgTe/CdTe quantum well, and they can be considered as the fingerprint of the helical quantum spin Hall edge states in a two-dimensional topological insulator.

  18. Nonlocal vibration analysis of circular double-layered graphene sheets resting on an elastic foundation subjected to thermal loading

    NASA Astrophysics Data System (ADS)

    Ansari, Reza; Torabi, Jalal

    2016-06-01

    Based on the nonlocal elasticity theory, the vibration behavior of circular double-layered graphene sheets (DLGSs) resting on the Winkler- and Pasternak-type elastic foundations in a thermal environment is investigated. The governing equation is derived on the basis of Eringen's nonlocal elasticity and the classical plate theory (CLPT). The initial thermal loading is assumed to be due to a uniform temperature rise throughout the thickness direction. Using the generalized differential quadrature (GDQ) method and periodic differential operators in radial and circumferential directions, respectively, the governing equation is discretized. DLGSs with clamped and simply-supported boundary conditions are studied and the influence of van der Waals (vdW) interaction forces is taken into account. In the numerical results, the effects of various parameters such as elastic medium coefficients, radius-to-thickness ratio, thermal loading and nonlocal parameter are examined on both in-phase and anti-phase natural frequencies. The results show that the thermal load and elastic foundation respectively decreases and increases the fundamental frequencies of DLGSs.

  19. Nonlocal topological magnetoelectric effect by Coulomb interaction at a topological insulator-ferromagnet interface

    NASA Astrophysics Data System (ADS)

    Rex, Stefan; Nogueira, Flavio S.; Sudbø, Asle

    2016-01-01

    The interface between a topological insulator and a ferromagnetic insulator exhibits an interesting interplay of topological Dirac electrons and magnetism. As has been shown recently, the breaking of time-reversal invariance by magnetic order generates a Chern-Simons term in the action, that in turn leads to a Berry phase and a magnetoelectric effect of topological origin. Here, we consider the system in the presence of a long-range Coulomb interaction between the Dirac electrons, and find that the magnetoelectric effect of the fluctuating electric field becomes nonlocal. We derive a Landau-Lifshitz equation for the fluctuation-induced magnetization dynamics and the Euler-Lagrange equation of the Coulomb field by explicit one-loop calculations. Via the Coulomb interaction, divergences in the in-plane magnetization affect the magnetization dynamics over large distances in a topologically protected way.

  20. Modified formula of nonlocal electron transport in a laser-produced plasma

    SciTech Connect

    Xu, Y. ); He, X.T. China Center of Advanced Science Technology , P.O. Box 8730, Beijing 100080 )

    1994-07-01

    A nonlocal heat-transport formula for electrons is derived to include the terms associated with the electrostatic potential and [partial derivative]/[partial derivative][ital v]([ital f][sub 0],[ital f][sub 1]) in the Fokker-Planck (FP) equation. Then the FP equation for a strongly inhomogeneous plasma is solved. It is found that the behavior of the electron thermal conductivity at a large temperature gradient is considerably affected by the electrostatic field, and the thermal conductivity [kappa]/[kappa][sub SH] for electrons scales as 1/[ital k] in a large temperature gradient [ital k] when there exists a non-negligible electrostatic field, where [kappa][sub SH] is the Spitzer-Haerm heat coefficient.

  1. Chimera states in systems of nonlocal nonidentical phase-coupled oscillators

    NASA Astrophysics Data System (ADS)

    Xie, Jianbo; Kao, Hsien-Ching; Knobloch, Edgar

    2015-03-01

    Chimera states consisting of domains of coherently and incoherently oscillating nonlocally coupled phase oscillators in systems with spatial inhomogeneity are studied. The inhomogeneity is introduced through the dependence of the oscillator frequency on its location. Two types of spatial inhomogeneity, localized and spatially periodic, are considered and their effects on the existence and properties of multicluster and traveling chimera states are explored. The inhomogeneity is found to break up splay states, to pin the chimera states to specific locations, and to trap traveling chimeras. Many of these states can be studied by constructing an evolution equation for a complex order parameter. Solutions of this equation are in good agreement with the results of numerical simulations.

  2. Conservation laws for a class of soil water equations

    NASA Astrophysics Data System (ADS)

    Yaşar, Emrullah

    2010-10-01

    In this paper, we consider a class of nonlinear partial differential equations which model soil water infiltration, redistribution and extraction in a bedded soil profile irrigated by a line source drip irrigation system. By using the nonlocal conservation theorem method and the partial Lagrangian approach, conservation laws are presented. It is observed that both approaches lead to the nontrivial and infinite conservation laws.

  3. Dirac equation in the background of the Nutku helicoid metric

    NASA Astrophysics Data System (ADS)

    Birkandan, T.; Hortaçsu, M.

    2007-09-01

    We study the solutions of the Dirac equation in the background of the Nutku helicoid metric. This metric has curvature singularities, which necessitates imposing a boundary to exclude this point. We use the Atiyah-Patodi-Singer [Math. Proc. Cambridge Philos. Soc. 77, 43 (1975)] nonlocal spectral boundary conditions for both the four and the five dimensional manifolds.

  4. Effect of competing cubic-quintic nonlinearities on the modulational instability in nonlocal Kerr-type media

    NASA Astrophysics Data System (ADS)

    Tagwo, H.; Tiofack, C. G. L.; Dafounansou, O.; Mohamadou, A.; Kofane, T. C.

    2016-03-01

    We investigate analytically and numerically the modulational instability (MI) of plane waves under competing nonlocal cubic-local quintic nonlinearities. The generic properties of the MI gain spectra are then demonstrated for the Gaussian response function, exponential response function, and rectangular response function. Special attention is paid to competing nonlocal cubic-local quintic nonlinearities on the MI. We observe that the focusing local quintic nonlinearity increases the growth rate and bandwidth of instability contrary to the small values of defocusing local quintic nonlinearity which decrease the growth rate and bandwidth of instability. Numerical simulations of the full model equation describing the dynamics of the waves are been carried out and leads to the development of pulse trains, depending upon the sign the quintic nonlinearity.

  5. Nonlinear vibration of carbon nanotube embedded in viscous elastic matrix under parametric excitation by nonlocal continuum theory

    NASA Astrophysics Data System (ADS)

    Wang, Yi-Ze; Wang, Yue-Sheng; Ke, Liao-Liang

    2016-09-01

    In the present work, the nonlinear vibration of a carbon nanotube which is subjected to the external parametric excitation is studied. By the nonlocal continuum theory and nonlinear von Kármán beam theory, the governing equation of the carbon nanotube is derived with the consideration of the large deformation. The principle parametric resonance of the nanotube is discussed and the approximation explicit solution is presented by the multiple scale method. Numerical calculations are performed. It can be observed that when the mode number is 1, the stable region can be significantly changed by the parametric excitation, length-to-diameter ratio and matrix stiffness. This phenomenon becomes different to appear if the mode number increases. Moreover, the small scale effects have great influences on the positive bifurcation point for the short carbon nanotube, and the nonlocal continuum theory can present the proper model.

  6. The theoretical polarization of pure scattering axisymmetric circumstellar envelopes

    NASA Technical Reports Server (NTRS)

    Fox, G. K.

    1994-01-01

    The Sobolev approach to the scattering of starlight through a pure scattering circumstellar envelope is developed. The theoretical polarization due to electron scattering in Be star envelopes is calculated for two geometries (an equatorially enhanced envelope and a spheroidal envelope). Only the disk-type envelope is found to yield a maximum polarization consistent with the observed range for Be stars. A lower limit, analytical approximation to the theoretical polarization from a pure scattering envelope is obtained.

  7. Nonlocal similarity based DEM super resolution

    NASA Astrophysics Data System (ADS)

    Xu, Zekai; Wang, Xuewen; Chen, Zixuan; Xiong, Dongping; Ding, Mingyue; Hou, Wenguang

    2015-12-01

    This paper discusses a new topic, DEM super resolution, to improve the resolution of an original DEM based on its partial new measurements obtained with high resolution. A nonlocal algorithm is introduced to perform this task. The original DEM was first divided into overlapping patches, which were classified either as "test" or "learning" data depending on whether or not they are related to high resolution measurements. For each test patch, the similar patches in the learning dataset were identified via template matching. Finally, the high resolution DEM of the test patch was restored by the weighted sum of similar patches under the condition that the reconstruction weights were the same in different resolution cases. A key assumption of this strategy is that there are some repeated or similar modes in the original DEM, which is quite common. Experiments were done to demonstrate that we can restore a DEM by preserving the details without introducing artifacts. Statistic analysis was also conducted to show that this method can obtain higher accuracy than traditional interpolation methods.

  8. Personnel occupied woven envelope robot

    NASA Technical Reports Server (NTRS)

    Wessling, Francis; Teoh, William; Ziemke, M. Carl

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) provides an alternative to extravehicular activity (EVA) of space suited astronauts and/or use of long slender manipulator arms such as are used in the Shuttle Remote Manipulator System. POWER provides the capability for a shirt sleeved astronaut to perform such work by entering a control pod through air locks at both ends of an inflated flexible bellows (access tunnel). The exoskeleton of the tunnel is a series of six degrees of freedom (Six-DOF) articulated links compressible to 1/6 of their fully extended length. The operator can maneuver the control pod to almost any location within about 50 m of the base attachment to the space station. POWER can be envisioned as a series of hollow Six-DOF manipulator segments or arms wherein each arm grasps the shoulder of the next arm. Inside the hollow arms ia a bellow-type access tunnel. The control pod is the fist of the series of linked hollow arms. The fingers of the fist are conventional manipulator arms under direct visual control of the nearby operator in the pod. The applications and progress to date of the POWER system is given.

  9. Safeguards Envelope Progress FY09

    SciTech Connect

    Richard Metcalf; Robert Bean

    2009-09-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters which nuclear facilities may operate within to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details advanced statistical techniques will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). As a result of the U.S. having no operating nuclear chemical reprocessing plants, there has been a strong interest in obtaining process monitoring data from the ICPP. The ICPP was shut down in 1996 and a recent effort has been made to retrieve the PM data from storage in a data mining effort. In a simulation based on this data, multi-tank and multi-attribute correlations were tested against synthetic diversion scenarios. Kernel regression smoothing was used to fit a curve to the historical data, and multivariable, residual analysis and cumulative sum techniques set parameters for operating conditions. Diversion scenarios were created and tested, showing improved results when compared with a previous study utilizing only one-variable Z- testing7.

  10. Electrostatic envelope modes in multi-component non-thermal plasmas

    NASA Astrophysics Data System (ADS)

    Saiful Islam, Md; Sultana, Sharmin; Mamun, A. A.

    2016-07-01

    A theoretical study of envelope type solitary structures and their modulational instability has been made in a multi-component unmagnetized non-thermal plasma (consisting of negatively charged immobile heavy ions, inertial light ions and non-thermal electrons of two distinct temperatures). The cubic nonlinear Schrödinger equation (which describes the evolution of a slowly varying wave envelope with space and time) is derived by adopting the multiple scale (in space and time) perturbation technique. It is found that the plasma system under consideration supports two types (bright and dark) envelope solitons. It is also seen that the dark (bright) envelope solitons are modulationally stable (unstable). The variation of the growth rate of the unstable bright envelope solitons with various plasma parameters (e.g. wave number, temperature of plasma non-thermality, etc.) are found to be significant. The modulational instability criterions of the envelope modes are also seen to be influenced due to the variation of the intrinsic plasma parameters. This theoretical study may be useful in understanding the basic features of localized electrostatic structures in some space plasma systems (viz. Saturn's magnetosphere) where high energetic particles are available.

  11. Resource envelope concepts for mission planning

    NASA Technical Reports Server (NTRS)

    Ibrahim, K. Y.; Weiler, J. D.; Tokaz, J. C.

    1991-01-01

    Seven proposed methods for creating resource envelopes for Space Station Freedom mission planning are detailed. Four reference science activity models are used to illustrate the effect of adding operational flexibility to mission timelines. For each method, a brief explanation is given along with graphs to illustrate the application of the envelopes to the power and crew resources. The benefits and costs of each method are analyzed in terms of resource utilization. In addition to the effect on individual activities, resource envelopes are analyzed at the experiment level.

  12. Electromagnetic envelope solitary waves with transverse perturbation in a plasma

    SciTech Connect

    Borhanian, J.

    2013-04-15

    The system of fluid-Maxwell equations governing the two-dimensional dynamics of electromagnetic waves in a plasma is analyzed by means of multiple scale perturbation method. It is shown that the evolution of the amplitude of wave field is governed by a two-dimensional nonlinear Schroedinger equation. The stability of bright envelope solitons is studied using the variational method. It is found that the development of transverse periodic perturbations on bright solitons is faster for a plasma with near critical density. Dynamics of electromagnetic bright solitons is investigated in the long-wave approximation. Our model predicts the appearance of collapse of electromagnetic waves in plasmas and describes the collapse dynamics at initial stages.

  13. Envelope evolution of a laser pulse in an active medium

    SciTech Connect

    Fisher, D.L.; Tajima, T.; Downer, M.C.; Siders, C.W.

    1994-11-01

    The authors show that the envelope velocity, v{sub env}, of a short laser pulse can, via propagation in an active medium, be made less than, equal to, or even greater than c, the vacuum phase velocity of light. Simulation results, based on moving frame propagation equations coupling the laser pulse, active medium and plasma, are presented, as well as equations that determines the design value of super- and sub-luminous v{sub env}. In this simulation the laser pulse evolves in time in a moving frame as opposed to their earlier work where the profile was fixed. The elimination of phase slippage and pump depletion effects in the laser wakefield accelerator is discussed as a particular application. Finally they discuss media properties necessary for an experimental realization of this technique.

  14. Conservation properties and potential systems of vorticity-type equations

    SciTech Connect

    Cheviakov, Alexei F.

    2014-03-15

    Partial differential equations of the form divN=0, N{sub t}+curl M=0 involving two vector functions in R{sup 3} depending on t, x, y, z appear in different physical contexts, including the vorticity formulation of fluid dynamics, magnetohydrodynamics (MHD) equations, and Maxwell's equations. It is shown that these equations possess an infinite family of local divergence-type conservation laws involving arbitrary functions of space and time. Moreover, it is demonstrated that the equations of interest have a rather special structure of a lower-degree (degree two) conservation law in R{sup 4}(t,x,y,z). The corresponding potential system has a clear physical meaning. For the Maxwell's equations, it gives rise to the scalar electric and the vector magnetic potentials; for the vorticity equations of fluid dynamics, the potentialization inverts the curl operator to yield the fluid dynamics equations in primitive variables; for MHD equations, the potential equations yield a generalization of the Galas-Bogoyavlenskij potential that describes magnetic surfaces of ideal MHD equilibria. The lower-degree conservation law is further shown to yield curl-type conservation laws and determined potential equations in certain lower-dimensional settings. Examples of new nonlocal conservation laws, including an infinite family of nonlocal material conservation laws of ideal time-dependent MHD equations in 2+1 dimensions, are presented.

  15. Nonlocal theory and finite element modeling of nano-composites

    NASA Astrophysics Data System (ADS)

    Alvinasab, Ali

    This research is concerned with fundamentals of modeling nano-composites. The study contains two major parts, namely, numerical modeling of nanocomposites and nonlocal theory based approach for predicting behavior of Carbon Nanotubes (CNTs). Computational modeling of glass (silica) fibers having micro-scale outer dimensions and nano-scale internal structures was performed to assess its mechanical behavior. Self-assembly technique was used to synthesize the individual fibers of approximately 5 mum in length with a hexagonal cross-section (2mum between two opposite sides) and honeycomb-like internal nano-structures. These fibers have several potential applications including synthesis of multifunctional composite materials. Numerical modeling of the individual fibers was performed using continuum mechanics based approach wherein linear elastic elements were utilized within a commercial finite element (FE) analysis software. A representative volume element approach was adopted for computational efficiency. Appropriate loads and boundary conditions were used to derive stress-strain relationship (stiffness matrix) which has six independent constants for the individual fiber. Force-displacement relationships under simulated nanoindentation were obtained for the actual fiber (with six independent constants) and under transversely isotropic approximation. The contact problem was solved for the transversely isotropic case, which indicated a much stiffer fiber compared to the FE predictions. This difference is likely due to the geometric nonlinearity considered in FE analysis yielding accurate results for large displacements. The effective mechanical properties of randomly oriented nano-structured glass fiber composite are evaluated by using a continuum mechanics based FE model. The longitudinal and transverse properties of aligned fiber are calculated. Then the equivalent material properties for tilted fiber with different fiber orientations are obtained. Based on equivalent

  16. Ill-Posedness of the Hydrostatic Euler and Singular Vlasov Equations

    NASA Astrophysics Data System (ADS)

    Han-Kwan, Daniel; Nguyen, Toan T.

    2016-09-01

    In this paper, we develop an abstract framework to establish ill-posedness, in the sense of Hadamard, for some nonlocal PDEs displaying unbounded unstable spectra. We apply this to prove the ill-posedness for the hydrostatic Euler equations as well as for the kinetic incompressible Euler equations and the Vlasov-Dirac-Benney system.

  17. Solar envelope concepts: moderate density building applications

    NASA Astrophysics Data System (ADS)

    Knowles, R. L.; Berry, R. D.

    1980-04-01

    The public policy mechanism for guaranteeing solar access is conceptualized as a solar zoning envelope that allows the largest possible building bulk on a land parcel without shadowing neighboring properties during specified times. Step-by-step methods for generating solar envelopes are described with extensive drawings, showing a variety of urban platting and lot configurations. Development and design possibilities are examined on a selected set of Los Angeles sites with typically diverse urban characteristics. Envelope attributes suitable for encouraging moderate-density commercial and residential building are examined in the context of two hypothetical but realistic development programs: one for speculative office buildings and one for condominium housing. Numerous illustrations of envelope forms and prototypical building designs are provided.

  18. Personnel occupied woven envelope robot power

    NASA Technical Reports Server (NTRS)

    Wessling, F. C.

    1988-01-01

    The Personnel Occupied Woven Envelope Robot (POWER) concept has evolved over the course of the study. The goal of the project was the development of methods and algorithms for solid modeling for the flexible robot arm.

  19. Non-local magnetoresistance in YIG/Pt nanostructures

    SciTech Connect

    Goennenwein, Sebastian T. B. Pernpeintner, Matthias; Gross, Rudolf; Huebl, Hans; Schlitz, Richard; Ganzhorn, Kathrin; Althammer, Matthias

    2015-10-26

    We study the local and non-local magnetoresistance of thin Pt strips deposited onto yttrium iron garnet. The local magnetoresistive response, inferred from the voltage drop measured along one given Pt strip upon current-biasing it, shows the characteristic magnetization orientation dependence of the spin Hall magnetoresistance. We simultaneously also record the non-local voltage appearing along a second, electrically isolated, Pt strip, separated from the current carrying one by a gap of a few 100 nm. The corresponding non-local magnetoresistance exhibits the symmetry expected for a magnon spin accumulation-driven process, confirming the results recently put forward by Cornelissen et al. [“Long-distance transport of magnon spin information in a magnetic insulator at room temperature,” Nat. Phys. (published online 14 September 2015)]. Our magnetotransport data, taken at a series of different temperatures as a function of magnetic field orientation, rotating the externally applied field in three mutually orthogonal planes, show that the mechanisms behind the spin Hall and the non-local magnetoresistance are qualitatively different. In particular, the non-local magnetoresistance vanishes at liquid Helium temperatures, while the spin Hall magnetoresistance prevails.

  20. Nonlocal dielectric effects in core-shell nanowires.

    SciTech Connect

    McMahon, J. M.; Gray, S. K.; Schatz, G. C.

    2010-01-01

    We study the optical spectra and near fields of core-shell nanowires (nanoshells), using a recently developed finite-difference method that allows for a spatially nonlocal dielectric response. We first analyze the parameters of the nonlocal model by making comparisons with related experimental data and previous theoretical work. We then investigate how nonlocal effects are dependent on nanoshell features, such as shell thickness, overall size, and the ratio of core radius to shell radius. We demonstrate that the shell thickness along the longitudinal direction of the incident light is the primary controlling factor of nonlocal effects, which appear as anomalous absorption resonances and blueshifts in the localized surface plasmon resonance (LSPR) positions, relative to local theory. In addition, we show that the amount of blueshift depends on the order of the LSPR. The optical responses of nanoshells immersed in various refractive index (RI) environments are also studied. We show that the nonlocal anomalous absorption features are relatively insensitive to RI changes, but the blueshift of the dipolar LSPR varies nonlinearly.

  1. Examining the effect of nonlocality in (d ,n ) transfer reactions

    NASA Astrophysics Data System (ADS)

    Ross, A.; Titus, L. J.; Nunes, F. M.

    2016-07-01

    Background: In the past year we have been exploring the effect of the explicit inclusion of nonlocality in (d ,p ) reactions. Purpose: The goal of this paper is to extend previous studies to (d ,n ) reactions, which, although similar to (d ,p ) reactions, have specific properties that merit inspection. Method: We apply our methods (both the distorted-wave Born approximation and the adiabatic wave approximation) to (d ,n ) reactions on 16O,40Ca,48Ca,126Sn,132Sn , and 208Pb at 20 and 50 MeV. Results: We look separately at the modifications introduced by nonlocality in the final bound and scattering states as well as the consequences reflected on the differential angular distributions. The cross sections obtained when using nonlocality explicitly are significantly different than those using the local approximation, just as in (d ,p ) reactions. Due to the particular role of the Coulomb force in the bound state, often we found the effects of nonlocality to be larger in (d ,n ) than in (d ,p ) reactions. Conclusions: Our results confirm the importance of including nonlocality explicitly in deuteron-induced reactions.

  2. Nonlocal regularization of inverse problems: a unified variational framework.

    PubMed

    Yang, Zhili; Jacob, Mathews

    2013-08-01

    We introduce a unifying energy minimization framework for nonlocal regularization of inverse problems. In contrast to the weighted sum of square differences between image pixels used by current schemes, the proposed functional is an unweighted sum of inter-patch distances. We use robust distance metrics that promote the averaging of similar patches, while discouraging the averaging of dissimilar patches. We show that the first iteration of a majorize-minimize algorithm to minimize the proposed cost function is similar to current nonlocal methods. The reformulation thus provides a theoretical justification for the heuristic approach of iterating nonlocal schemes, which re-estimate the weights from the current image estimate. Thanks to the reformulation, we now understand that the widely reported alias amplification associated with iterative nonlocal methods are caused by the convergence to local minimum of the nonconvex penalty. We introduce an efficient continuation strategy to overcome this problem. The similarity of the proposed criterion to widely used nonquadratic penalties (e.g., total variation and lp semi-norms) opens the door to the adaptation of fast algorithms developed in the context of compressive sensing; we introduce several novel algorithms to solve the proposed nonlocal optimization problem. Thanks to the unifying framework, these fast algorithms are readily applicable for a large class of distance metrics. PMID:23014745

  3. Local and nonlocal conductance enhancement due to Cooper pair splitting

    NASA Astrophysics Data System (ADS)

    Wei, Jian; Chandrasekhar, V.

    2012-12-01

    Enhanced local conductance due to Andreev reflection is well known for high transparency Normal metal-Superconductor (NS) interface. For low transparency NS junctions, observation of two-electron tunneling contribution (enhanced Andreev reflection) to current was also reported previously. In our recent work [J Wei and V Chandrasekhar, Nat. Phys. 6, 494 (2010)], for a three-terminal Cooper pair splitter geometry, i.e., with two closely placed NS junctions sharing the same S terminal, we were able do a 2D scan of both local and nonlocal differential resistance, since for our ideal tunneling junctions there is little current redistribution (flow from one normal-metal lead to the other via the superconducting lead). In contrast to previous 1D nonlocal resistance measurements, 2D scans clearly show regime with pronounced contribution of the nonlocal processes to both local and nonlocal conductance enhancement. The enhanced local conductance and negative nonlocal resistance are consistent with enhanced Cooper pair splitting, and dynamical Coulomb blockade could be the origin of this enhancement.

  4. Efficient test to demonstrate genuine three particle nonlocality

    NASA Astrophysics Data System (ADS)

    Mukherjee, Kaushiki; Paul, Biswajit; Sarkar, Debasis

    2015-11-01

    According to the studies of genuine tripartite nonlocality in discrete variable quantum systems conducted so far, Svetlichny inequality is considered as the best Bell-type inequality to detect genuine (three way) nonlocality of pure tripartite genuine entangled states. In the present work, we have considered another Bell-type inequality (which has been reported as the 99th facet of NS 2 local polytope in Bancal et al (2013 Phys. Rev. A 88 014102), to reveal genuine tripartite nonlocality of generalized GHZ (Greenberger-Horne-Zeilinger) class and a subclass of extended GHZ class states Acín et al (2000 Phys. Rev. Lett. 85 1560) thereby proving the conjecture given by Bancal et al (2013 Phys. Rev. A 88 014102) for the GGHZ class and the subclass of extended GHZ states. We compare the violation of this inequality with Svetlichny inequality which reveals the efficiency of the former inequality over the latter to demonstrate genuine nonlocality using the above classes of quantum states. Even in some cases discord monogamy score can be used as a better measure of quantum correlation over Svetlichny inequality for those classes of pure states. Besides, the 99th facet inequality is found efficient not only for revealing genuine nonlocal behavior of correlations emerging in systems using pure entangled states but also in some cases of mixed entangled states over Svetlichny inequality and some well known measures of entanglement.

  5. Nonlocal regularization of inverse problems: a unified variational framework

    PubMed Central

    Yang, Zhili; Jacob, Mathews

    2014-01-01

    We introduce a unifying energy minimization framework for nonlocal regularization of inverse problems. In contrast to the weighted sum of square differences between image pixels used by current schemes, the proposed functional is an unweighted sum of inter-patch distances. We use robust distance metrics that promote the averaging of similar patches, while discouraging the averaging of dissimilar patches. We show that the first iteration of a majorize-minimize algorithm to minimize the proposed cost function is similar to current non-local methods. The reformulation thus provides a theoretical justification for the heuristic approach of iterating non-local schemes, which re-estimate the weights from the current image estimate. Thanks to the reformulation, we now understand that the widely reported alias amplification associated with iterative non-local methods are caused by the convergence to local minimum of the nonconvex penalty. We introduce an efficient continuation strategy to overcome this problem. The similarity of the proposed criterion to widely used non-quadratic penalties (eg. total variation and `p semi-norms) opens the door to the adaptation of fast algorithms developed in the context of compressive sensing; we introduce several novel algorithms to solve the proposed non-local optimization problem. Thanks to the unifying framework, these fast algorithms are readily applicable for a large class of distance metrics. PMID:23014745

  6. Survival of an Enveloped Virus on Toys.

    PubMed

    Bearden, Richard L; Casanova, Lisa M

    2016-08-01

    Children's toys may carry respiratory viruses. Inactivation of a lipid-enveloped bacteriophage, Φ6, was measured on a nonporous toy at indoor temperature and relative humidity (RH). Inactivation was approximately 2log10 after 24 hours at 60% RH and 6.8log10 at 10 hours at 40% RH. Enveloped viruses can potentially survive on toys long enough to result in exposures. PMID:27144972

  7. Creating a Lunar EVA Work Envelope

    NASA Technical Reports Server (NTRS)

    Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David

    2009-01-01

    A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.

  8. Nonperturbative embedding for highly nonlocal Hamiltonians

    NASA Astrophysics Data System (ADS)

    Subaşı, Yiǧit; Jarzynski, Christopher

    2016-07-01

    The need for Hamiltonians with many-body interactions arises in various applications of quantum computing. However, interactions beyond two-body are difficult to realize experimentally. Perturbative gadgets were introduced to obtain arbitrary many-body effective interactions using Hamiltonians with at most two-body interactions. Although valid for arbitrary k -body interactions, their use is limited to small k because the strength of interaction is k th order in perturbation theory. In this paper we develop a nonperturbative technique for obtaining effective k -body interactions using Hamiltonians consisting of at most l -body interactions with l nonlocal Hamiltonian. This technique does not suffer from the aforementioned shortcoming of perturbative methods and requires only one ancilla qubit for each k -body interaction irrespective of the value of k . It works best for Hamiltonians with a few many-body interactions involving a large number of qubits and can be used together with perturbative gadgets to embed Hamiltonians of considerable complexity in proper subspaces of two-local Hamiltonians. We describe how our technique can be implemented in a hybrid (gate-based and adiabatic) as well as solely adiabatic quantum computing scheme.

  9. Nonlocal means filter-based speckle tracking.

    PubMed

    Afsham, Narges; Rasoulian, Abtin; Najafi, Mohammad; Abolmaesumi, Purang; Rohling, Robert

    2015-08-01

    The objective of sensorless freehand 3-D ultrasound imaging is to eliminate the need for additional tracking hardware and reduce cost and complexity. However, the accuracy of current out-of-plane pose estimation is main obstacle for full 6-degree-of-freedom (DoF) tracking. We propose a new filter-based speckle tracking framework to increase the accuracy of out-of-plane displacement estimation. In this framework, we use the displacement estimation not only for the specific speckle pattern, but for the entire image. We develop a nonlocal means (NLM) filter based on a probabilistic normal variance mixture model of ultrasound, known as Rician-inverse Gaussian (RiIG). To aggregate the local displacement estimations, Stein's unbiased risk estimate (SURE) is used as a quality measure of the estimations. We derive an explicit analytical form of SURE for the RiIG model and use it as a weight factor. The proposed filter-based speckle tracking framework is formulated and evaluated for three commonly used noise models, including the RiIG model. The out-of-plane estimations are compared with our previously proposed model-based algorithm in a set of ex vivo experiments for different tissue types. We show that the proposed RiIG filter-based method is more accurate and less tissue-dependent than the other methods. The proposed method is also evaluated in vivo on the spines of five different subjects to assess the feasibility of a clinical application. The 6-DoF transform parameters are estimated and compared with the electromagnetic tracker measurements. The results show higher tracking accuracy for typical small lateral displacements and tilt rotations between image pairs. PMID:26276959

  10. Genetic diversity of koala retroviral envelopes.

    PubMed

    Xu, Wenqin; Gorman, Kristen; Santiago, Jan Clement; Kluska, Kristen; Eiden, Maribeth V

    2015-03-01

    Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A) were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process. PMID:25789509

  11. Cooling of neutron stars with diffusive envelopes

    NASA Astrophysics Data System (ADS)

    Beznogov, M. V.; Fortin, M.; Haensel, P.; Yakovlev, D. G.; Zdunik, J. L.

    2016-08-01

    We study the effects of heat blanketing envelopes of neutron stars on their cooling. To this aim, we perform cooling simulations using newly constructed models of the envelopes composed of binary ion mixtures (H-He, He-C, C-Fe) varying the mass of lighter ions (H, He or C) in the envelope. The results are compared with those calculated using the standard models of the envelopes which contain the layers of lighter (accreted) elements (H, He and C) on top of the Fe layer, varying the mass of accreted elements. The main effect is that the chemical composition of the envelopes influences their thermal conductivity and, hence, thermal insulation of the star. For illustration, we apply these results to estimate the internal temperature of the Vela pulsar and to study the cooling of neutron stars of ages of 105 - 106 yr at the photon cooling stage. The uncertainties of the cooling models associated with our poor knowledge of chemical composition of the heat insulating envelopes strongly complicate theoretical reconstruction of the internal structure of cooling neutron stars from observations of their thermal surface emission.

  12. The joke envelope: a neglected precursor of the psychic envelope concept in Freud's writing.

    PubMed

    Spero, Moshe Halevi

    2009-01-01

    The concepts of the primeval skin ego, psychic envelope, and related pre-ego containing and wrapping functions elaborated respectively by Esther Bick, Didier Anzieu, and Francis Tustin occupy an important position in contemporary psychoanalytic theory and clinical practice. The psychic envelope begins as a virtual mental protostructure ("proto" because it is not yet based on fully symbolized representations) that holds the budding mind together pending further developments. With maturity, the enveloping functions adopt symbolized, metaphoric form (for example, the aesthetic use of cloth, the analytic framework), but can regress to more concrete and pathological forms. The aforementioned authors based their ideas on a cluster of specific allusions to the idea of a psychic covering, barrier, or envelope in Freud's work. Yet they neglected one reference, hidden in Freud's analysis of the structure ofjokes and humor: the 'joke envelope"--die witzige Einkleidung. The present essay explores Freud's use of the term Einkleidung, including his intriguing idea that a joke requires three people whereas a dream does not and the fact that Freud nowhere speaks of a "dream envelope. "I take the "joke envelope" beyond its original context and posit a relationship between laughter and the early, normative traumas of breathing, crying, and loss, and the dawn of rhythmic envelopes that enable mentalization. Jokes and joking symbolically repeat the early rupture and rapture of breathing and self-other differentiation and the internalization of maternal containing and envelopment. PMID:20578439

  13. Envelope solitary waves exist and collide head-on without phase shift in a dusty plasma

    PubMed Central

    Zhang, Heng; Qi, Xin; Duan, Wen-Shan; Yang, Lei

    2015-01-01

    The rarefactive KdV solitary waves in a dusty plasma have been extensively studied analytically and found experimentally in the previous works. Though the envelope solitary wave described by a nonlinear Schrödinger equation (NLSE) has been proposed by using the reductive perturbation method, it is first verified by using the particle-in-cell (PIC) numerical method in this paper. Surprisingly, there is no phase shift after the head on collision between two envelope solitary waves, while it is sure that there are phase shifts of two colliding KdV solitary waves after head on collision. PMID:26383642

  14. Envelope solitary waves exist and collide head-on without phase shift in a dusty plasma.

    PubMed

    Zhang, Heng; Qi, Xin; Duan, Wen-Shan; Yang, Lei

    2015-01-01

    The rarefactive KdV solitary waves in a dusty plasma have been extensively studied analytically and found experimentally in the previous works. Though the envelope solitary wave described by a nonlinear Schrödinger equation (NLSE) has been proposed by using the reductive perturbation method, it is first verified by using the particle-in-cell (PIC) numerical method in this paper. Surprisingly, there is no phase shift after the head on collision between two envelope solitary waves, while it is sure that there are phase shifts of two colliding KdV solitary waves after head on collision. PMID:26383642

  15. Nonlocal thermo-mechanical vibration analysis of functionally graded nanobeams in thermal environment

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Farzad; Salari, Erfan

    2015-08-01

    In this paper, the thermal effect on free vibration characteristics of functionally graded (FG) size-dependent nanobeams subjected to various types of thermal loading is investigated by presenting a Navier type solution and employing a semi analytical differential transform method (DTM) for the first time. Two kinds of thermal loading, namely, linear temperature rise and nonlinear temperature rise are studied. Material properties of FG nanobeam are supposed to vary continuously along the thickness according to the power-law form and the material properties are assumed to be temperature-dependent. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived through Hamilton's principle and they are solved applying DTM. According to the numerical results, it is revealed that the proposed modeling and semi analytical approach can provide accurate frequency results of the FG nanobeams as compared to analytical results and also some cases in the literature. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as thermal effect, material distribution profile, small scale effects, mode number and boundary conditions on the normalized natural frequencies of the temperature-dependent FG nanobeams in detail. It is explicitly shown that the vibration behaviour of a FG nanobeams is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of FG nanobeams.

  16. Nonlocal stochastic mixing-length theory and the velocity profile in the turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Dekker, H.; de Leeuw, G.; Maassen van den Brink, A.

    1995-02-01

    Turbulence mixing by finite size eddies will be treated by means of a novel formulation of nonlocal K-theory, involving sample paths and a stochastic closure hypothesis, which implies a well defined recipe for the calculation of sampling and transition rates. The connection with the general theory of stochastic processes will be established. The relation with other nonlocal turbulence models (e.g. transilience and spectral diffusivity theory) is also discussed. Using an analytical sampling rate model (satisfying exchange) the theory is applied to the boundary layer (using a scaling hypothesis), which maps boundary layer turbulence mixing of scalar densities onto a nondiffusive (Kubo-Anderson or kangaroo) type stochastic process. The resulting transpport equation for longitudinal momentum P x ≡ ϱ U is solved for a unified description of both the inertial and the viscous sublayer including the crossover. With a scaling exponent ε ≈ 0.58 (while local turbulence would amount to ε → ∞) the velocity profile U+ = ƒ(y +) is found to be in excellent agreement with the experimental data. Inter alia (i) the significance of ε as a turbulence Cantor set dimension, (ii) the value of the integration constant in the logarithmic region (i.e. if y+ → ∞), (iii) linear timescaling, and (iv) finite Reynolds number effects will be investigated. The (analytical) predictions of the theory for near-wall behaviour (i.e. if y+ → 0) of fluctuating quantities also perfectly agree with recent direct numerical simulations.

  17. Transition between free-space Helmholtz equation solutions with plane sources and parabolic wave equation solutions.

    PubMed

    Mahillo-Isla, R; Gonźalez-Morales, M J; Dehesa-Martínez, C

    2011-06-01

    The slowly varying envelope approximation is applied to the radiation problems of the Helmholtz equation with a planar single-layer and dipolar sources. The analyses of such problems provide procedures to recover solutions of the Helmholtz equation based on the evaluation of solutions of the parabolic wave equation at a given plane. Furthermore, the conditions that must be fulfilled to apply each procedure are also discussed. The relations to previous work are given as well. PMID:21643384

  18. Nonlocal quartic interactions and universality classes in perovskite manganites.

    PubMed

    Singh, Rohit; Dutta, Kishore; Nandy, Malay K

    2015-07-01

    A modified Ginzburg-Landau model with a screened nonlocal interaction in the quartic term is treated via Wilson's renormalization-group scheme at one-loop order to explore the critical behavior of the paramagnetic-to-ferromagnetic phase transition in perovskite manganites. We find the Fisher exponent η to be O(ε) and the correlation exponent to be ν=1/2+O(ε) through epsilon expansion in the parameter ε=d(c)-d, where d is the space dimension, d(c)=4+2σ is the upper critical dimension, and σ is a parameter coming from the nonlocal interaction in the model Hamiltonian. The ensuing critical exponents in three dimensions for different values of σ compare well with various existing experimental estimates for perovskite manganites with various doping levels. This suggests that the nonlocal model Hamiltonian contains a wide variety of such universality classes. PMID:26274140

  19. Dynamics of entropic measurement-induced nonlocality in structured reservoirs

    SciTech Connect

    Hu, Ming-Liang; Fan, Heng

    2012-09-15

    We propose the entropic measurement-induced nonlocality (MIN) as the maximal increment of von Neumann entropy induced by the locally non-disturbing measurement, and study its behaviors in both the independent and common structured reservoirs. We present schemes for preserving the MIN, and show that for certain initial states the MIN, including the quantum correlations, can even be enhanced by the common reservoir. Additionally, we also show that the different measures of MIN may give different qualitative characterizations of nonlocal properties, i.e., it is rather measure dependent than state dependent. - Highlights: Black-Right-Pointing-Pointer Features of the entropic measurement-induced nonlocality (MIN). Black-Right-Pointing-Pointer Comparison of MIN with other quantum correlation measures. Black-Right-Pointing-Pointer Enhancement of MIN and other quantum correlations by common reservoir. Black-Right-Pointing-Pointer Relativity of the geometric and entropic MIN measures.

  20. Bound on Hardy's nonlocality from the principle of information causality

    SciTech Connect

    Ahanj, Ali; Kunkri, Samir; Rai, Ashutosh; Rahaman, Ramij; Joag, Pramod S.

    2010-03-15

    Recently, the principle of nonviolation of information causality [Nature 461, 1101 (2009)] has been proposed as one of the foundational properties of nature. We explore the Hardy's nonlocality theorem for two-qubit systems, in the context of generalized probability theory, restricted by the principle of nonviolation of information causality. Applying a sufficient condition for information causality violation, we derive an upper bound on the maximum success probability of Hardy's nonlocality argument. We find that the bound achieved here is higher than that allowed by quantum mechanics but still much less than what the no-signaling condition permits. We also study the Cabello type nonlocality argument (a generalization of Hardy's argument) in this context.

  1. Bounding the persistency of the nonlocality of W states

    NASA Astrophysics Data System (ADS)

    Diviánszky, Péter; Trencsényi, Réka; Bene, Erika; Vértesi, Tamás

    2016-04-01

    The nonlocal properties of the W states are investigated under particle loss. By removing all but two particles from an N -qubit W state, the resulting two-qubit state is still entangled. Hence, the W state has high persistency of entanglement. We ask an analogous question regarding the persistency of nonlocality [see N. Brunner and T. Vértesi, Phys. Rev. A 86, 042113 (2012), 10.1103/PhysRevA.86.042113]. Namely, we inquire what is the minimal number of particles that must be removed from the W state so that the resulting state becomes local. We bound this value in function of N qubits by considering Bell nonlocality tests with two alternative settings per site. In particular, we find that this value is between 2 N /5 and N /2 for large N . We also develop a framework to establish bounds for more than two settings per site.

  2. Jammed Clusters and Non-locality in Dense Granular Flows

    NASA Astrophysics Data System (ADS)

    Kharel, Prashidha; Rognon, Pierre

    We investigate the micro-mechanisms underpinning dense granular flow behaviour from a series of DEM simulations of pure shear flows of dry grains. We observe the development of transient clusters of jammed particles within the flow. Typical size of such clusters is found to scale with the inertial number with a power law that is similar to the scaling of shear-rate profile relaxation lengths observed previously. Based on the simple argument that transient clusters of size l exist in the dense flow regime, the formulation of steady state condition for non-homogeneous shear flow results in a general non-local relation, which is similar in form to the non-local relation conjectured for soft glassy flows. These findings suggest the formation of jammed clusters to be the key micro-mechanism underpinning non-local behaviour in dense granular flows. Particles and Grains Laboratory, School of Civil Engineering, The University of Sydney, Sydney, NSW 2006, Australia.

  3. Hardy's proof of nonlocality in the presence of noise

    SciTech Connect

    Ghirardi, GianCarlo; Marinatto, Luca

    2006-12-15

    We extend the validity of Hardy's nonlocality without inequalities proof to cover the case of special one-parameter classes of nonpure statistical operators. These mixed states are obtained by mixing the Hardy states with a completely chaotic noise or with a colored noise and they represent a realistic description of imperfect preparation processes of (pure) Hardy states in nonlocality experiments. Within such a framework we are able to exhibit a precise range of values of the parameter measuring the noise affecting the nonoptimal preparation of an arbitrary Hardy state, for which it is still possible to put into evidence genuine nonlocal effects. Equivalently, our work exhibits particular classes of bipartite mixed states whose constituents do not admit any local and deterministic hidden variable model reproducing the quantum mechanical predictions.

  4. Generalized conservation laws in non-local field theories

    NASA Astrophysics Data System (ADS)

    Kegeles, Alexander; Oriti, Daniele

    2016-04-01

    We propose a geometrical treatment of symmetries in non-local field theories, where the non-locality is due to a lack of identification of field arguments in the action. We show that the existence of a symmetry of the action leads to a generalized conservation law, in which the usual conserved current acquires an additional non-local correction term, obtaining a generalization of the standard Noether theorem. We illustrate the general formalism by discussing the specific physical example of complex scalar field theory of the type describing the hydrodynamic approximation of Bose-Einstein condensates. We expect our analysis and results to be of particular interest for the group field theory formulation of quantum gravity.

  5. A Framework for Bounding Nonlocality of State Discrimination

    NASA Astrophysics Data System (ADS)

    Childs, Andrew M.; Leung, Debbie; Mančinska, Laura; Ozols, Maris

    2013-11-01

    We consider the class of protocols that can be implemented by local quantum operations and classical communication (LOCC) between two parties. In particular, we focus on the task of discriminating a known set of quantum states by LOCC. Building on the work in the paper Quantum nonlocality without entanglement (Bennett et al., Phys Rev A 59:1070-1091, 1999), we provide a framework for bounding the amount of nonlocality in a given set of bipartite quantum states in terms of a lower bound on the probability of error in any LOCC discrimination protocol. We apply our framework to an orthonormal product basis known as the domino states and obtain an alternative and simplified proof that quantifies its nonlocality. We generalize this result for similar bases in larger dimensions, as well as the “rotated” domino states, resolving a long-standing open question (Bennett et al., Phys Rev A 59:1070-1091, 1999).

  6. Nonlocal thermal transport across embedded few-layer graphene sheets

    DOE PAGESBeta

    Liu, Ying; Huxtable, Scott T.; Yang, Bao; Sumpter, Bobby G.; Qiao, Rui

    2014-11-13

    Thermal transport across the interfaces between few-layer graphene sheets and soft materials exhibits intriguing anomalies when interpreted using the classical Kapitza model, e.g., the conductance of the same interface differs greatly for different modes of interfacial thermal transport. Using atomistic simulations, we show that such thermal transport follows a nonlocal flux-temperature drop constitutive law and is characterized jointly by a quasi-local conductance and a nonlocal conductance instead of the classical Kapitza conductance. Lastly, the nonlocal model enables rationalization of many anomalies of the thermal transport across embedded few-layer graphene sheets and should be used in studies of interfacial thermal transportmore » involving few-layer graphene sheets or other ultra-thin layered materials.« less

  7. Nonlocal thermal transport across embedded few-layer graphene sheets

    SciTech Connect

    Liu, Ying; Huxtable, Scott T.; Yang, Bao; Sumpter, Bobby G.; Qiao, Rui

    2014-11-13

    Thermal transport across the interfaces between few-layer graphene sheets and soft materials exhibits intriguing anomalies when interpreted using the classical Kapitza model, e.g., the conductance of the same interface differs greatly for different modes of interfacial thermal transport. Using atomistic simulations, we show that such thermal transport follows a nonlocal flux-temperature drop constitutive law and is characterized jointly by a quasi-local conductance and a nonlocal conductance instead of the classical Kapitza conductance. Lastly, the nonlocal model enables rationalization of many anomalies of the thermal transport across embedded few-layer graphene sheets and should be used in studies of interfacial thermal transport involving few-layer graphene sheets or other ultra-thin layered materials.

  8. Nonlinear kinetic description of Raman growth using an envelope code, and comparisons with Vlasov simulations

    NASA Astrophysics Data System (ADS)

    Bénisti, Didier; Morice, Olivier; Gremillet, Laurent; Siminos, Evangelos; Strozzi, David J.

    2010-10-01

    In this paper, we present our nonlinear kinetic modeling of stimulated Raman scattering in a uniform and collisionless plasma using envelope equations. We recall the derivation of these equations, as well as our theoretical predictions for each of the nonlinear kinetic terms, the precision of which having been carefully checked against Vlasov simulations. We particularly focus here on the numerical resolution of these equations, which requires the additional concept of "self-optimization" that we explain, and we describe the envelope code BRAMA that we used. As an application of our modeling, we present one-dimensional BRAMA simulations of stimulated Raman scattering which predict threshold intensities, as well as time scales for Raman growth above threshold, in very good agreement with those inferred from Vlasov simulations. Finally, we discuss the differences between our modeling and other published ones.

  9. Morphological evolution and migration of void in bi-piezoelectric interface based on nonlocal phase field method

    NASA Astrophysics Data System (ADS)

    Li, H. B.; Wang, X.

    2016-05-01

    This paper reports the result of investigation into the morphological evolution and migration of void in bi-piezoelectric material interface by utilizing nonlocal phase field model and finite element method (FEM), where the small scale effect containing the long-range forces among atoms is considered. The nonlocal elastic strain energy and the nonlocal electric energy around the void are firstly calculated by the finite element method. Then based on the finite difference method (FDM), the thermodynamic equilibrium equation containing the surface energy and anisotropic diffusivity is solved to simulate the morphological evolution and migration of elliptical void in bi-piezoelectric films interface. Results show that the way of load condition plays a significant role in the evolution process, and the boundary of void's long axis gradually collapses toward the center of ellipse. In addition, the evolutionary speed of left boundary gradually decreases with scale effect coefficient growth. This work can provide references for the safety evaluation of piezoelectric materials in micro electro mechanical system.

  10. Valley currents and nonlocal resistances of graphene nanostructures with broken inversion symmetry from the perspective of scattering theory

    NASA Astrophysics Data System (ADS)

    Kirczenow, George

    2015-09-01

    Valley currents and nonlocal resistances of graphene nanostructures with broken inversion symmetry are considered theoretically in the linear response regime. Scattering state wave functions of electrons entering the nanostructure from the contacts represented by groups of ideal leads are calculated by solving the Lippmann-Schwinger equation and are projected onto the valley state subspaces to obtain the valley velocity fields and total valley currents in the nanostructures. In the tunneling regime when the Fermi energy is in the spectral gap around the Dirac point energy, inversion symmetry breaking is found to result in strong enhancement of the nonlocal four-terminal Büttiker-Landauer resistance and in valley currents several times stronger than the conventional electric current. These strong valley currents are the direct result of the injection of electrons from a contact into the graphene in the tunneling regime. They are chiral and occur near contacts from which electrons are injected into the nanostructure whether or not a net electric current flows through the contact. It is also pointed out that enhanced nonlocal resistances in the linear response regime are not a signature of valley currents arising from the combined effect of the electric field and Berry curvature on the velocities of electrons.

  11. Simulating Convection in Stellar Envelopes

    NASA Astrophysics Data System (ADS)

    Tanner, Joel

    Understanding convection in stellar envelopes, and providing a mathematical description of it, would represent a substantial advance in stellar astrophysics. As one of the largest sources of uncertainty in stellar models, existing treatments of convection fail to account for many of the dynamical effects of convection, such as turbulent pressure and asymmetry in the velocity field. To better understand stellar convection, we must be able to study and examine it in detail, and one of the best tools for doing so is numerical simulation. Near the stellar surface, both convective and radiative process play a critical role in determining the structure and gas dynamics. By following these processes from first principles, convection can be simulated self-consistently and accurately, even in regions of inefficient energy transport where existing descriptions of convection fail. Our simulation code includes two radiative transfer solvers that are based on different assumptions and approximations. By comparing simulations that differ only in their respective radiative transfer methods, we are able to isolate the effect that radiative efficiency has on the structure of the superadiabatic layer. We find the simulations to be in good general agreement, but they show distinct differences in the thermal structure in the superadiabatic layer and atmosphere. Using the code to construct a grid of three-dimensional radiation hydrodynamic simulations, we investigate the link between convection and various chemical compositions. The stellar parameters correspond to main-sequence stars at several surface gravities, and span a range in effective temperatures (4500 < Teff < 6400). Different chemical compositions include four metallicities (Z = 0.040, 0.020, 0.010, 0.001), three helium abundances (Y = 0.1, 0.2, 0.3) and several levels of alpha-element enhancement. Our grid of simulations shows that various convective properties, such as velocity and the degree of superadiabaticity, are

  12. Nonlocal Stochastic Model for the Free Scalar Field Theory

    NASA Astrophysics Data System (ADS)

    Namsrai, Kh.

    1981-05-01

    The free scalar field is investigated within the framework of the Davidson stochastic model and of the hypothesis on space-time stochasticity. It is shown that the resulting Markov field obtained by averaging in this space-time is equivalent to a nonlocal Euclidean Markov field with the times scaled by a common factor which depends on the diffusion parameter ν. Our result generalizes Guerra and Ruggiero's procedure of stochastic quantization of scalar fields. On the basis of the assumption about unobservability of ν in quantum field theory, the Efimov nonlocal theory is obtained from Euclidean Markov field with form factors of the class of entire analytical functions.

  13. Fine-grained uncertainty relation and nonlocality of tripartite systems

    NASA Astrophysics Data System (ADS)

    Pramanik, T.; Majumdar, A. S.

    2012-02-01

    The upper bound of the fine-grained uncertainty relation is different for classical physics, quantum physics, and no-signaling theories with maximal nonlocality (superquantum correlation), as was shown in the case of bipartite systems [J. Oppenheim and S. Wehner, ScienceSCIEAS0036-807510.1126/science.1192065 330, 1072 (2010)]. Here, we extend the fine-grained uncertainty relation to the case of tripartite systems. We show that the fine-grained uncertainty relation determines the nonlocality of tripartite systems as manifested by the Svetlichny inequality, discriminating between classical physics, quantum physics, and superquantum correlations.

  14. Local and nonlocal parallel heat transport in general magnetic fields

    SciTech Connect

    Del-Castillo-Negrete, Diego B; Chacon, Luis

    2011-01-01

    A novel approach for the study of parallel transport in magnetized plasmas is presented. The method avoids numerical pollution issues of grid-based formulations and applies to integrable and chaotic magnetic fields with local or nonlocal parallel closures. In weakly chaotic fields, the method gives the fractal structure of the devil's staircase radial temperature profile. In fully chaotic fields, the temperature exhibits self-similar spatiotemporal evolution with a stretched-exponential scaling function for local closures and an algebraically decaying one for nonlocal closures. It is shown that, for both closures, the effective radial heat transport is incompatible with the quasilinear diffusion model.

  15. Two-Dimensional Heterojunctions from Nonlocal Manipulations of the Interactions.

    PubMed

    Rösner, M; Steinke, C; Lorke, M; Gies, C; Jahnke, F; Wehling, T O

    2016-04-13

    We propose to create lateral heterojunctions in two-dimensional materials based on nonlocal manipulations of the Coulomb interaction using structured dielectric environments. By means of ab initio calculations for MoS2 as well as generic semiconductor models, we show that the Coulomb interaction-induced self-energy corrections in real space are sufficiently nonlocal to be manipulated externally, but still local enough to induce spatially sharp interfaces within a single homogeneous monolayer to form heterojunctions. We find a type-II heterojunction band scheme promoted by a laterally structured dielectric environment, which exhibits a sharp band gap crossover within less than 5 unit cells. PMID:26918626

  16. To the non-local theory of cold nuclear fusion.

    PubMed

    Alexeev, Boris V

    2014-10-01

    In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the 'acoustic CF' could be realized from the position of the non-local hydrodynamics. PMID:26064528

  17. Quantum nonlocal effects on optical properties of spherical nanoparticles

    SciTech Connect

    Moradi, Afshin

    2015-02-15

    To study the scattering of electromagnetic radiation by a spherical metallic nanoparticle with quantum spatial dispersion, we develop the standard nonlocal Mie theory by allowing for the excitation of the quantum longitudinal plasmon modes. To describe the quantum nonlocal effects, we use the quantum longitudinal dielectric function of the system. As in the standard Mie theory, the electromagnetic fields are expanded in terms of spherical vector wavefunctions. Then, the usual Maxwell boundary conditions are imposed plus the appropriate additional boundary conditions. Examples of calculated extinction spectra are presented, and it is found that the frequencies of the subsidiary peaks, due to quantum bulk plasmon excitations exhibit strong dependence on the quantum spatial dispersion.

  18. Nonlocal Poisson-Fermi model for ionic solvent

    NASA Astrophysics Data System (ADS)

    Xie, Dexuan; Liu, Jinn-Liang; Eisenberg, Bob

    2016-07-01

    We propose a nonlocal Poisson-Fermi model for ionic solvent that includes ion size effects and polarization correlations among water molecules in the calculation of electrostatic potential. It includes the previous Poisson-Fermi models as special cases, and its solution is the convolution of a solution of the corresponding nonlocal Poisson dielectric model with a Yukawa-like kernel function. The Fermi distribution is shown to be a set of optimal ionic concentration functions in the sense of minimizing an electrostatic potential free energy. Numerical results are reported to show the difference between a Poisson-Fermi solution and a corresponding Poisson solution.

  19. Faithful test of nonlocal realism with entangled coherent states

    SciTech Connect

    Lee, Chang-Woo; Jeong, Hyunseok; Paternostro, Mauro

    2011-02-15

    We investigate the violation of Leggett's inequality for nonlocal realism using entangled coherent states and various types of local measurements. We prove mathematically the relation between the violation of the Clauser-Horne-Shimony-Holt form of Bell's inequality and Leggett's one when tested by the same resources. For Leggett inequalities, we generalize the nonlocal realistic bound to systems in Hilbert spaces larger than bidimensional ones and introduce an optimization technique that allows one to achieve larger degrees of violation by adjusting the local measurement settings. Our work describes the steps that should be performed to produce a self-consistent generalization of Leggett's original arguments to continuous-variable states.

  20. Self-induced mode transformation in nonlocal nonlinear media.

    PubMed

    Izdebskaya, Yana V; Desyatnikov, Anton S; Kivshar, Yuri S

    2013-09-20

    We report on the first experimental observation of self-induced optical mode transformations in nonlocal nonlinear media. We show that the quadrupole Hermite-Gaussian mode experiences complex nonlinear dynamics in a nematic liquid crystal, including power-dependent conversion into a radially symmetric Laguerre-Gaussian mode. The physical mechanism responsible for self-induced transformation is the excitation of internal modes of a metastable quadrupole nonlocal soliton and its subsequent transmutation into a robust soliton with a bright peak surrounded by a bright ring. We also observe the onset of transformations of higher-order modes, proving the generic character of this nonlinear phenomenon. PMID:24093262

  1. Nonlocal Poisson-Fermi model for ionic solvent.

    PubMed

    Xie, Dexuan; Liu, Jinn-Liang; Eisenberg, Bob

    2016-07-01

    We propose a nonlocal Poisson-Fermi model for ionic solvent that includes ion size effects and polarization correlations among water molecules in the calculation of electrostatic potential. It includes the previous Poisson-Fermi models as special cases, and its solution is the convolution of a solution of the corresponding nonlocal Poisson dielectric model with a Yukawa-like kernel function. The Fermi distribution is shown to be a set of optimal ionic concentration functions in the sense of minimizing an electrostatic potential free energy. Numerical results are reported to show the difference between a Poisson-Fermi solution and a corresponding Poisson solution. PMID:27575084

  2. Quasi-periodic transformations of nonlocal spatial solitons.

    PubMed

    Buccoliero, Daniel; Desyatnikov, Anton S

    2009-06-01

    We study quasi-periodic transformations between nonlocal spatial solitons of different symmetries triggered by modulational instability and resembling a self-induced mode converter. Transformation dynamics of solitons with zero angular momentum, e.g. the quadrupole-type soliton, reveal the equidistant spectrum of spatial field oscillations typical for the breather-type solutions. In contrast, the transformations of nonlocal solitons carrying orbital angular momentum, such as 2x3 soliton matrix, are accompanied by their spiralling and corresponding spectra of field oscillations show mixing of three characteristic spatial frequencies. PMID:19506609

  3. Characterizing the geometrical edges of nonlocal two-qubit gates

    SciTech Connect

    Balakrishnan, S.; Sankaranarayanan, R.

    2009-05-15

    Nonlocal two-qubit gates are geometrically represented by tetrahedron known as Weyl chamber within which perfect entanglers form a polyhedron. We identify that all edges of the Weyl chamber and polyhedron are formed by single parametric gates. Nonlocal attributes of these edges are characterized using entangling power and local invariants. In particular, SWAP{sup -{alpha}} family of gates with 0{<=}{alpha}{<=}1 constitutes one edge of the Weyl chamber with SWAP{sup -1/2} being the only perfect entangler. Finally, optimal constructions of controlled-NOT using SWAP{sup -1/2} gate and gates belong to three edges of the polyhedron are presented.

  4. Non-local heat transport in static solar coronal loops

    NASA Astrophysics Data System (ADS)

    Ciaravella, A.; Peres, G.; Serio, S.

    1991-04-01

    The limits of applicability of the Spitzer-Harm thermal conductivity in solar coronal loops is investigated, and it is shown that the ratio of electron mean-free path to temperature scale height in large-scale structures can approach the limits of the Spitzer-Harm theory. A nonlocal formulation of heat transport is used to compute a grid of loop models: the effects of nonlocal transport on the distribution of differential emission measure are particularly important in the coronal part of loops longer than the pressure scale height.

  5. An integrable shallow water equation with linear and nonlinear dispersion.

    PubMed

    Dullin, H R; Gottwald, G A; Holm, D D

    2001-11-01

    We use asymptotic analysis and a near-identity normal form transformation from water wave theory to derive a 1+1 unidirectional nonlinear wave equation that combines the linear dispersion of the Korteweg-deVries (KdV) equation with the nonlinear/nonlocal dispersion of the Camassa-Holm (CH) equation. This equation is one order more accurate in asymptotic approximation beyond KdV, yet it still preserves complete integrability via the inverse scattering transform method. Its traveling wave solutions contain both the KdV solitons and the CH peakons as limiting cases. PMID:11690414

  6. Legendre-tau approximations for functional differential equations

    NASA Technical Reports Server (NTRS)

    Ito, K.; Teglas, R.

    1986-01-01

    The numerical approximation of solutions to linear retarded functional differential equations are considered using the so-called Legendre-tau method. The functional differential equation is first reformulated as a partial differential equation with a nonlocal boundary condition involving time-differentiation. The approximate solution is then represented as a truncated Legendre series with time-varying coefficients which satisfy a certain system of ordinary differential equations. The method is very easy to code and yields very accurate approximations. Convergence is established, various numerical examples are presented, and comparison between the latter and cubic spline approximation is made.

  7. Legendre-Tau approximations for functional differential equations

    NASA Technical Reports Server (NTRS)

    Ito, K.; Teglas, R.

    1983-01-01

    The numerical approximation of solutions to linear functional differential equations are considered using the so called Legendre tau method. The functional differential equation is first reformulated as a partial differential equation with a nonlocal boundary condition involving time differentiation. The approximate solution is then represented as a truncated Legendre series with time varying coefficients which satisfy a certain system of ordinary differential equations. The method is very easy to code and yields very accurate approximations. Convergence is established, various numerical examples are presented, and comparison between the latter and cubic spline approximations is made.

  8. Three-dimensional radiation-hydrodynamics calculations of the envelopes of young planets embedded in protoplanetary disks

    SciTech Connect

    D'Angelo, Gennaro; Bodenheimer, Peter E-mail: peter@ucolick.org

    2013-11-20

    We perform global three-dimensional (3D) radiation-hydrodynamics calculations of the envelopes surrounding young planetary cores of 5, 10, and 15 Earth masses, located in a protoplanetary disk at 5 and 10 AU from a solar-mass star. We apply a nested-grid technique to resolve the thermodynamics of the disk at the orbital-radius length scale and that of the envelope at the core-radius length scale. The gas is modeled as a solar mixture of molecular and atomic hydrogen, helium, and their ions. The equation of state accounts for both gas and radiation, and gas energy includes contributions from rotational and vibrational states of molecular hydrogen and from ionization of atomic species. Dust opacities are computed from first principles, applying the full Mie theory. One-dimensional (1D) calculations of planet formation are used to supplement the 3D calculations by providing energy deposition rates in the envelope due to solids accretion. We compare 1D and 3D envelopes and find that masses and gas accretion rates agree within factors of 2, and so do envelope temperatures. The trajectories of passive tracers are used to define the size of 3D envelopes, resulting in radii much smaller than the Hill radius and smaller than the Bondi radius. The moments of inertia and angular momentum of the envelopes are determined and the rotation rates are derived from the rigid-body approximation, resulting in slow bulk rotation. We find that the polar flattening is ≲ 0.05. The dynamics of the accretion flow are examined by tracking the motion of tracers that move into the envelope. The anisotropy of this flow is characterized in terms of both its origin and impact site at the envelope surface. Gas merges with the envelope preferentially at mid- to high latitudes.

  9. The role of the stagnant-film thickness in mesoscopic modeling of equiaxed grain envelopes

    NASA Astrophysics Data System (ADS)

    Souhar, Youssef; De Felice, Valerio F.; Založnik, Miha; Combeau, Hervé; Beckermann, Christoph

    2016-03-01

    The mesoscopic envelope model overcomes the limitations of phase-field methods. It can be applied at larger scales and can include fluid flow at reasonable computing cost. It consists of the description of a dendritic grain by an envelope that links the active dendrite branches. The grain is modelled as an evolving porous medium and the liquid-solid phase change and solute transport are modelled by volume-averaged equations. The velocities of the dendrite tips are determined by the local solute-concentration field in the proximity of the envelope through an analytical stagnant-film model. In this publication, we present our implementation of the model for a binary alloy and we discuss the influence of the stagnant-film thickness, the principal model parameter, on the predicted 3D equiaxed grains by comparisons with the scaling laws for binary-alloy dendrites obtained in recent experiments by Melendez and Beckermann.

  10. Higher order nonlocal formalism for linear analysis of a magnetized multispecies plasma with inhomogeneous flows

    SciTech Connect

    Gavrishchaka, V.V.; Ganguli, G.I.; Bakshi, P.M.; Koepke, M.E.

    1998-01-01

    The formalism necessary to study the collective properties of a plasma system with inhomogeneous flows is nonlocal and generally in the form of an integrodifferential equation. Usually the eigenvalue condition is reduced to a second-order differential equation for simplicity. While the gross physical behavior of the system can be obtained from the second-order differential equation level of description, higher-order corrections are necessary for greater accuracy. The limit in which the scale-size of the velocity inhomogeneity is large compared to the ion gyroradius is considered and a transverse flow profile sharply localized in space ({open_quotes}top-hat{close_quotes} profile) is assumed. In this limit, a simple analytical method for the solution of the general eigenvalue condition to all orders is developed. A comparison of the properties of the solutions obtained from the second-order differential equation level of description with those obtained from higher orders is presented. Both the resonant (dissipative) and the nonresonant (reactive) effects of velocity shear are considered. It is found that while the overall features are well represented by the second-order level of description, the higher-order corrections moderate the destabilizing effects due to velocity shear, which can be quite significant in some cases. {copyright} {ital 1998 American Institute of Physics.}

  11. Featured Image: Orbiting Stars Share an Envelope

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-03-01

    This beautiful series of snapshots from a simulation (click for a better look!) shows what happens when two stars in a binary system become enclosed in the same stellar envelope. In this binary system, one of the stars has exhausted its hydrogen fuel and become a red giant, complete with an expanding stellar envelope composed of hydrogen and helium. Eventually, the envelope expands so much that the companion star falls into it, where it releases gravitational potential energy into the common envelope. A team led by Sebastian Ohlmann (Heidelberg Institute for Theoretical Studies and University of Wrzburg) recently performed hydrodynamic simulations of this process. Ohlmann and collaborators discovered that the energy release eventually triggers large-scale flow instabilities, which leads to turbulence within the envelope. This process has important consequences for how these systems next evolve (for instance, determining whether or not a supernova occurs!). You can check out the authors video of their simulated stellar inspiral below, or see their paper for more images and results from their study.CitationSebastian T. Ohlmann et al 2016 ApJ 816 L9. doi:10.3847/2041-8205/816/1/L9

  12. The cell envelope proteome of Aggregatibacter actinomycetemcomitans

    PubMed Central

    Smith, Kenneth P.; Fields, Julia G.; Voogt, Richard D.; Deng, Bin; Lam, Ying-Wai; Mintz, Keith P.

    2014-01-01

    Summary The cell envelope of Gram-negative bacteria serves a critical role in maintenance of cellular homeostasis, resistance to external stress, and host-pathogen interactions. Envelope protein composition is influenced by the physiological and environmental demands placed on the bacterium. In this study, we report a comprehensive compilation of cell envelope proteins from the periodontal and systemic pathogen Aggregatibacter actinomycetemcomitans VT1169, an afimbriated serotype b strain. The urea-extracted membrane proteins were identified by mass spectrometry-based shotgun proteomics. The membrane proteome, isolated from actively growing bacteria under normal laboratory conditions, included 648 proteins representing 28% of the predicted ORFs in the genome. Bioinformatic analyses were used to annotate and predict the cellular location and function of the proteins. Surface adhesins, porins, lipoproteins, numerous influx and efflux pumps, multiple sugar, amino acid and iron transporters, and components of the type I, II and V secretion systems were identified. Periplasmic space and cytoplasmic proteins with chaperone function were also identified. 107 proteins with unknown function were associated with the cell envelope. Orthologs of a subset of these uncharacterized proteins are present in other bacterial genomes, while others are found exclusively in A. actinomycetemcomitans. This knowledge will contribute to elucidating the role of cell envelope proteins in bacterial growth and survival in the oral cavity. PMID:25055881

  13. Modeling non-local thermodynamic equilibrium plasma using the Flexible Atomic Code data

    NASA Astrophysics Data System (ADS)

    Han, Bo; Wang, Feilu; Salzmann, David; Zhao, Gang

    2015-04-01

    We present a new code, RCF ("Radiative-Collisional code based on FAC"), which is used to simulate steady-state plasmas under non-local thermodynamic equilibrium condition, especially photoinization-dominated plasmas. RCF takes almost all of the radiative and collisional atomic processes into a rate equation to interpret the plasmas systematically. The Flexible Atomic Code (FAC) supplies all the atomic data needed for RCF, which insures calculating completeness and consistency of atomic data. With four input parameters relating to the radiation source and target plasma, RCF calculates the population of levels and charge states, as well as potential emission spectrum. In a preliminary application, RCF successfully reproduced the results of a photoionization experiment with reliable atomic data. The effects of the most important atomic processes on the charge state distribution are also discussed.

  14. Towards a resolution of the cosmological singularity in non-local higher derivative theories of gravity

    SciTech Connect

    Biswas, Tirthabir; Koivisto, Tomi; Mazumdar, Anupam E-mail: T.S.Koivisto@uu.nl

    2010-11-01

    One of the greatest problems of standard cosmology is the Big Bang singularity. Previously it has been shown that non-local ghostfree higher-derivative modifications of Einstein gravity in the ultra-violet regime can admit non-singular bouncing solutions. In this paper we study in more details the dynamical properties of the equations of motion for these theories of gravity in presence of positive and negative cosmological constants and radiation. We find stable inflationary attractor solutions in the presence of a positive cosmological constant which renders inflation geodesically complete, while in the presence of a negative cosmological constant a cyclic universe emerges. We also provide an algorithm for tracking the super-Hubble perturbations during the bounce and show that the bouncing solutions are free from any perturbative instability.

  15. Analytical studies of fronts, colonies, and patterns: Combination of the Allee effect and nonlocal competition interactions

    NASA Astrophysics Data System (ADS)

    Clerc, M. G.; Escaff, D.; Kenkre, V. M.

    2010-09-01

    We present an analytic study of traveling fronts, localized colonies, and extended patterns arising from a reaction-diffusion equation which incorporates simultaneously two features: the well-known Allee effect and spatially nonlocal competition interactions. The former is an essential ingredient of most systems in population dynamics and involves extinction at low densities, growth at higher densities, and saturation at still higher densities. The latter feature is also highly relevant, particularly to biological systems, and goes beyond the unrealistic assumption of zero-range interactions. We show via exact analytic methods that the combination of the two features yields a rich diversity of phenomena and permits an understanding of a variety of issues including spontaneous appearance of colonies.

  16. Spatial organization of vegetation arising from non-local excitation with local inhibition in tropical rainforests

    NASA Astrophysics Data System (ADS)

    Thompson, Sally; Katul, Gabriel; Terborgh, John; Alvarez-Loayza, Patricia

    2009-06-01

    The Janzen-Connell (JC) effect, which hypothesizes that recruitment and growth of seedlings is positively correlated to the distance from the parent tree, is shown to generate highly organized vegetation biomass spatial patterns when coupled to a revised Fisher-Kolmogorov (FK) equation. Spatial organization arises through a novel mechanism of non-local activation and local inhibition. Over a single generation, the revised FK model calculations predict a “hen and chicks” dynamic pattern with mature trees surrounded by new seedlings growing at characteristic spatial distances in agreement with field data. Over longer timescales, the importance of stochastic dynamics, such as those associated with randomly occurring light gaps, increase thereby causing a substantial deviation between predictions from the deterministic FK model and its stochastic counterpart derived to account for such random disturbances. At still longer timescales, however, statistical measures of the spatial organization, specifically the spatial density of mature trees and their minimum spacing, converge between these two model representations.

  17. A radially resolved kinetic model for nonlocal electron ripple diffusion losses in tokamaks

    SciTech Connect

    Robertson, Scott

    2006-09-15

    A relatively simple radially resolved kinetic model is applied to the ripple diffusion problem for electrons in tokamaks. The distribution function f(r,v) is defined on a two-dimensional grid, where r is the radial coordinate and v is the velocity coordinate. Particle transport in the radial direction is from ripple and banana diffusion and transport in the velocity direction is described by the Fokker-Planck equation. Particles and energy are replaced by source functions that are adjusted to maintain a constant central density and temperature. The relaxed profiles of f(r,v) show that the electron distribution function at the wall contains suprathermal electrons that have diffused from the interior that enhance ripple transport. The transport at the periphery is therefore nonlocal. The energy replacement times from the computational model are near to the experimental replacement times for tokamak discharges in the compilation by Pfeiffer and Waltz [Nucl. Fusion 19, 51 (1979)].

  18. A Dream of Yukawa — Non-Local Fields out of Non-Commutative Spacetime —

    NASA Astrophysics Data System (ADS)

    Naka, Shigefumi; Toyoda, Haruki; Takanashi, Takahiro; Umezawa, Eizo

    The coordinates of κ-Minkowski spacetime form Lie algebraic elements, in which time and space coordinates do not commute in spite of that space coordinates commute each other. The non-commutativity is realized by a Planck-length-scale constant κ - 1( ne 0), which is a universal constant other than the light velocity under the κ-Poincare transformation. Such a non-commutative structure can be realized by SO(1,4) generators in dS4 spacetime. In this work, we try to construct a κ-Minkowski like spacetime with commutative 4-dimensional spacetime based on Adsn+1 spacetime. Another aim of this work is to study invariant wave equations in this spacetime from the viewpoint of non-local field theory by H. Yukawa, who expected to realize elementary particle theories without divergence according to this viewpoint.

  19. Solar Dynamo Model with Diamagnetic Pumping and Nonlocal α-Effect

    NASA Astrophysics Data System (ADS)

    Kitchatinov, L. L.; Olemskoy, S. V.

    2012-02-01

    A combination of diamagnetic pumping and a nonlocal α-effect of the Babcock-Leighton type in a solar dynamo model is shown to reproduce observations of solar magnetic activity. The period of the solar cycle can be reproduced without reducing magnetic diffusivity in the bulk of the convection zone below the standard mixing-length value of 1013 cm2 s-1. The simulated global fields are antisymmetric about the equator, and the toroidal-to-poloidal field ratio is about one thousand. However, the time-latitude diagrams of magnetic fields in the model without meridional flow differ from observations. Only when the meridional flow is included and the α-effect profile peaking at mid-latitudes is applied, can the observed butterfly diagrams be reproduced.

  20. Classical open systems with nonlinear nonlocal dissipation and state-dependent diffusion: Dynamical responses and the Jarzynski equality

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hideo

    2011-11-01

    We have studied dynamical responses and the Jarzynski equality (JE) of classical open systems described by the generalized Caldeira-Leggett model with the nonlocal system-bath coupling. In the derived non-Markovian Langevin equation, the nonlinear nonlocal dissipative term and state-dependent diffusion term yielding multiplicative colored noise satisfy the fluctuation-dissipation relation. Simulation results for harmonic oscillator systems have shown the following: (a) averaged responses of the system to applied sinusoidal and step forces significantly depend on model parameters of magnitudes of additive and multiplicative noises and the relaxation time of colored noise, although stationary marginal probability distribution functions are independent of them, (b) a combined effect of nonlinear dissipation and multiplicative colored noise induces enhanced fluctuations <[x-]2> for an applied sinusoidal force, and (c) the JE holds for an applied ramp force independently of the model parameters with a work distribution function which is (symmetric) Gaussian and (asymmetric) non-Gaussian for additive and multiplicative noises, respectively. It has been shown that the non-Markovian Langevin equation in the local and overdamped limits is quite different from the widely adopted, phenomenological Markovian Langevin equation subjected to additive and multiplicative noises.

  1. Frustrated quantum phase diffusion and increased coherence of solitons due to nonlocality

    SciTech Connect

    Batz, Sascha; Peschel, Ulf

    2011-03-15

    We investigate the quantum properties of solitons with nonlocal self-interaction. We find significant changes when compared to the local interaction. Quantum phase diffusion of nonlocal solitons is always reduced with respect to the local interaction and vanishes in the strongly nonlocal limit. Thus, coherence is increased in the nonlocal case. Furthermore, we compare the intrinsic quantum wave packet spreading to the recently discussed classical Gordon-Haus effect for nonlocal solitons [V. Folli and C. Conti, Phys. Rev. Lett. 104, 193901 (2010)].

  2. An unresolved LINC in the nuclear envelope

    PubMed Central

    Torbati, Mehdi; Lele, Tanmay P; Agrawal, Ashutosh

    2016-01-01

    The nuclear envelope segregates the nucleoplasm from the cytoplasm and is a key feature of eukaryotic cells. Nuclear envelope architecture is comprised of two concentric membrane shells which fuse at multiple sites and yet maintain a uniform separation of 30–50 nm over the rest of the membrane. Studies have revealed the roles for numerous nuclear proteins in forming and maintaining the architecture of the nuclear envelope. However, there is a lack of consensus on the fundamental forces and physical mechanisms that establish the geometry. The objective of this review is to discuss recent findings in the context of membrane mechanics in an effort to define open questions and possible answers. PMID:27330571

  3. Envelope Solitons in Acoustically Dispersive Vitreous Silica

    NASA Technical Reports Server (NTRS)

    Cantrell, John H.; Yost, William T.

    2012-01-01

    Acoustic radiation-induced static strains, displacements, and stresses are manifested as rectified or dc waveforms linked to the energy density of an acoustic wave or vibrational mode via the mode nonlinearity parameter of the material. An analytical model is developed for acoustically dispersive media that predicts the evolution of the energy density of an initial waveform into a series of energy solitons that generates a corresponding series of radiation-induced static strains (envelope solitons). The evolutionary characteristics of the envelope solitons are confirmed experimentally in Suprasil W1 vitreous silica. The value (-11.9 plus or minus 1.43) for the nonlinearity parameter, determined from displacement measurements of the envelope solitons via a capacitive transducer, is in good agreement with the value (-11.6 plus or minus 1.16) obtained independently from acoustic harmonic generation measurements. The agreement provides strong, quantitative evidence for the validity of the model.

  4. Drug design from the cryptic inhibitor envelope

    PubMed Central

    Lee, Chul-Jin; Liang, Xiaofei; Wu, Qinglin; Najeeb, Javaria; Zhao, Jinshi; Gopalaswamy, Ramesh; Titecat, Marie; Sebbane, Florent; Lemaitre, Nadine; Toone, Eric J.; Zhou, Pei

    2016-01-01

    Conformational dynamics plays an important role in enzyme catalysis, allosteric regulation of protein functions and assembly of macromolecular complexes. Despite these well-established roles, such information has yet to be exploited for drug design. Here we show by nuclear magnetic resonance spectroscopy that inhibitors of LpxC—an essential enzyme of the lipid A biosynthetic pathway in Gram-negative bacteria and a validated novel antibiotic target—access alternative, minor population states in solution in addition to the ligand conformation observed in crystal structures. These conformations collectively delineate an inhibitor envelope that is invisible to crystallography, but is dynamically accessible by small molecules in solution. Drug design exploiting such a hidden inhibitor envelope has led to the development of potent antibiotics with inhibition constants in the single-digit picomolar range. The principle of the cryptic inhibitor envelope approach may be broadly applicable to other lead optimization campaigns to yield improved therapeutics. PMID:26912110

  5. Common Envelope and the Binding Energy Consideration

    NASA Astrophysics Data System (ADS)

    Irawati, P.; Mahasena, P.

    2014-08-01

    We report the results of our study on the common-envelope phase of the cataclysmic variables. We are investigating the role of additional energies, such as recombination energy and internal energy, in expelling the envelope of the primary star. In this work, we use the TWIN stellar evolution code which can evolve both stars in binary simultaneously. We analysed the energies involved by considering the binding energy of the core at the onset of the common envelope phase. The core of the primary is calculated using the hydrogen-exhausted layer with 10% hydrogen fraction. Our preliminary result shows that the internal energy plays a significant role while the recombination energy has only a small contribution to the energy budget of the cataclysmic variable evolution.

  6. Two flavor superconductivity in non-local models

    SciTech Connect

    Duhau, R.; Grunfeld, A.G.; Scoccola, N.N.

    2004-12-02

    In the present work we study a relativistic quark model at finite temperature and density with non-local quark-antiquark and quark-quark interactions with SU(2) flavour and SU(3) color symmetries. After proper bosonization, we analyze the structure of the corresponding phase diagram and discuss the competition between the chiral and 2SC phases.

  7. Modulational instability and solitons in nonlocal media with competing nonlinearities

    SciTech Connect

    Esbensen, B. K.; Bache, M.; Bang, O.; Wlotzka, A.; Krolikowski, W.

    2011-11-15

    We investigate analytically and numerically propagation and spatial localization of light in nonlocal media with competing nonlinearities. In particular, we discuss conditions for the modulational instability of plane waves and formation of spatial solitons. We show that the competing focusing and defocusing nonlinearities enable coexistence of dark or bright spatial solitons in the same medium by varying the intensity of the beam.

  8. Two-dimensional multipole solitons in nonlocal nonlinear media.

    PubMed

    Rotschild, Carmel; Segev, Mordechai; Xu, Zhiyong; Kartashov, Yaroslav V; Torner, Lluis; Cohen, Oren

    2006-11-15

    We present the experimental observation of scalar multipole solitons in highly nonlocal nonlinear media, including dipole, tripole, quadrupole, and necklace-type solitons, organized as arrays of out-of-phase bright spots. These complex solitons are metastable, but with a large parameters range where the instability is weak, permitting their experimental observation. PMID:17072407

  9. Incorporating anatomical side information into PET reconstruction using nonlocal regularization.

    PubMed

    Nguyen, Van-Giang; Lee, Soo-Jin

    2013-10-01

    With the introduction of combined positron emission tomography (PET)/computed tomography (CT) or PET/magnetic resonance imaging (MRI) scanners, there is an increasing emphasis on reconstructing PET images with the aid of the anatomical side information obtained from X-ray CT or MRI scanners. In this paper, we propose a new approach to incorporating prior anatomical information into PET reconstruction using the nonlocal regularization method. The nonlocal regularizer developed for this application is designed to selectively consider the anatomical information only when it is reliable. As our proposed nonlocal regularization method does not directly use anatomical edges or boundaries which are often used in conventional methods, it is not only free from additional processes to extract anatomical boundaries or segmented regions, but also more robust to the signal mismatch problem that is caused by the indirect relationship between the PET image and the anatomical image. We perform simulations with digital phantoms. According to our experimental results, compared to the conventional method based on the traditional local regularization method, our nonlocal regularization method performs well even with the imperfect prior anatomical information or in the presence of signal mismatch between the PET image and the anatomical image. PMID:23744678

  10. Vortex stabilization by means of spatial solitons in nonlocal media

    NASA Astrophysics Data System (ADS)

    Izdebskaya, Yana; Krolikowski, Wieslaw; Smyth, Noel F.; Assanto, Gaetano

    2016-05-01

    We investigate how optical vortices, which tend to be azimuthally unstable in local nonlinear materials, can be stabilized by a copropagating coaxial spatial solitary wave in nonlocal, nonlinear media. We focus on the formation of nonlinear vortex-soliton vector beams in reorientational soft matter, namely nematic liquid crystals, and report on experimental results, as well as numerical simulations.

  11. Nonlocal Hamiltonian gauge theories and their connection with lattice Hamiltonians

    SciTech Connect

    Ktorides, C.N.; Mavromatos, N.E.

    1985-06-15

    We introduce the concept of primitive Hamiltonian density for nonlocal Abelian gauge theories. We subsequently study the local limit both with respect to the continuum and with respect to a lattice structure introduced via hypercubic cells. The non-Abelian case is also discussed.

  12. Flare loop radiative hydrodynamics. III - Nonlocal radiative transfer effects

    NASA Technical Reports Server (NTRS)

    Canfield, R. C.; Fisher, G. H.; Mcclymont, A. N.

    1983-01-01

    The study has three goals. The first is to demonstrate that processes exist whose intrinsic nonlocal nature cannot be represented by local approximations. The second is to elucidate the physical nature and origins of these nonlocal processes. The third is to suggest that the methods and results described here may prove useful in constructing semiempirical models of the chromosphere by means more efficient than trial and error. Matrices are computed that describe the effect of a temperature perturbation at an arbitrary point in the loop on density, hydrogen ionized fraction, total radiative loss rate, and radiative loss rate of selected hydrogen lines and continua at all other points. It is found that the dominant nonlocal radiative transfer effects can be separated into flux divergence coefficient effects and upper level population effects. The former are most important when the perturbation takes place in a region of significant opacity. Upper level population effects arise in both optically thick and thin regions in response to nonlocal density, ionization, and interlocking effects.

  13. Perception and coding of envelopes in weakly electric fishes.

    PubMed

    Stamper, Sarah A; Fortune, Eric S; Chacron, Maurice J

    2013-07-01

    Natural sensory stimuli have a rich spatiotemporal structure and can often be characterized as a high frequency signal that is independently modulated at lower frequencies. This lower frequency modulation is known as the envelope. Envelopes are commonly found in a variety of sensory signals, such as contrast modulations of visual stimuli and amplitude modulations of auditory stimuli. While psychophysical studies have shown that envelopes can carry information that is essential for perception, how envelope information is processed in the brain is poorly understood. Here we review the behavioral salience and neural mechanisms for the processing of envelopes in the electrosensory system of wave-type gymnotiform weakly electric fishes. These fish can generate envelope signals through movement, interactions of their electric fields in social groups or communication signals. The envelopes that result from the first two behavioral contexts differ in their frequency content, with movement envelopes typically being of lower frequency. Recent behavioral evidence has shown that weakly electric fish respond in robust and stereotypical ways to social envelopes to increase the envelope frequency. Finally, neurophysiological results show how envelopes are processed by peripheral and central electrosensory neurons. Peripheral electrosensory neurons respond to both stimulus and envelope signals. Neurons in the primary hindbrain recipient of these afferents, the electrosensory lateral line lobe (ELL), exhibit heterogeneities in their responses to stimulus and envelope signals. Complete segregation of stimulus and envelope information is achieved in neurons in the target of ELL efferents, the midbrain torus semicircularis (Ts). PMID:23761464

  14. Rationale for switching to nonlocal functionals in density functional theory

    NASA Astrophysics Data System (ADS)

    Lazić, P.; Atodiresei, N.; Caciuc, V.; Brako, R.; Gumhalter, B.; Blügel, S.

    2012-10-01

    Density functional theory (DFT) has been steadily improving over the past few decades, becoming the standard tool for electronic structure calculations. The early local functionals (LDA) were eventually replaced by more accurate semilocal functionals (GGA) which are in use today. A major persisting drawback is the lack of the nonlocal correlation which is at the core of dispersive (van der Waals) forces, so that a large and important class of systems remains outside the scope of DFT. The vdW-DF correlation functional of Langreth and Lundqvist, published in 2004, was the first nonlocal functional which could be easily implemented. Beyond expectations, the nonlocal functional has brought significant improvement to systems that were believed not to be sensitive to nonlocal correlations. In this paper, we use the example of graphene nanodomes growing on the Ir(111) surface, where with an increase of the size of the graphene islands the character of the bonding changes from strong chemisorption towards almost pure physisorption. We demonstrate how the seamless character of the vdW-DF functionals makes it possible to treat all regimes self-consistently, proving to be a systematic and consistent improvement of DFT regardless of the nature of bonding. We also discuss the typical surface science example of CO adsorption on (111) surfaces of metals, which shows that the nonlocal correlation may also be crucial for strongly chemisorbed systems. We briefly discuss open questions, in particular the choice of the most appropriate exchange part of the functional. As the vdW-DF begins to appear implemented self-consistently in a number of popular DFT codes, with numerical costs close to the GGA calculations, we draw the attention of the DFT community to the advantages and benefits of the adoption of this new class of functionals.

  15. Differential Equations Modeling Crowd Interactions

    NASA Astrophysics Data System (ADS)

    Borsche, Raul; Colombo, Rinaldo M.; Garavello, Mauro; Meurer, Anne

    2015-08-01

    Nonlocal conservation laws are used to describe various realistic instances of crowd behaviors. First, a basic analytic framework is established through an ad hoc well-posedness theorem for systems of nonlocal conservation laws in several space dimensions interacting nonlocally with a system of ODEs. Numerical integrations show possible applications to the interaction of different groups of pedestrians and also with other agents.

  16. Lie symmetry analysis, conservation laws and exact solutions of the seventh-order time fractional Sawada-Kotera-Ito equation

    NASA Astrophysics Data System (ADS)

    Yaşar, Emrullah; Yıldırım, Yakup; Khalique, Chaudry Masood

    In this paper Lie symmetry analysis of the seventh-order time fractional Sawada-Kotera-Ito (FSKI) equation with Riemann-Liouville derivative is performed. Using the Lie point symmetries of FSKI equation, it is shown that it can be transformed into a nonlinear ordinary differential equation of fractional order with a new dependent variable. In the reduced equation the derivative is in Erdelyi-Kober sense. Furthermore, adapting the Ibragimov's nonlocal conservation method to time fractional partial differential equations, we obtain conservation laws of the underlying equation. In addition, we construct some exact travelling wave solutions for the FSKI equation using the sub-equation method.

  17. Tegument Assembly and Secondary Envelopment of Alphaherpesviruses

    PubMed Central

    Owen, Danielle J.; Crump, Colin M.; Graham, Stephen C.

    2015-01-01

    Alphaherpesviruses like herpes simplex virus are large DNA viruses characterized by their ability to establish lifelong latent infection in neurons. As for all herpesviruses, alphaherpesvirus virions contain a protein-rich layer called “tegument” that links the DNA-containing capsid to the glycoprotein-studded membrane envelope. Tegument proteins mediate a diverse range of functions during the virus lifecycle, including modulation of the host-cell environment immediately after entry, transport of virus capsids to the nucleus during infection, and wrapping of cytoplasmic capsids with membranes (secondary envelopment) during virion assembly. Eleven tegument proteins that are conserved across alphaherpesviruses have been implicated in the formation of the tegument layer or in secondary envelopment. Tegument is assembled via a dense network of interactions between tegument proteins, with the redundancy of these interactions making it challenging to determine the precise function of any specific tegument protein. However, recent studies have made great headway in defining the interactions between tegument proteins, conserved across alphaherpesviruses, which facilitate tegument assembly and secondary envelopment. We summarize these recent advances and review what remains to be learned about the molecular interactions required to assemble mature alphaherpesvirus virions following the release of capsids from infected cell nuclei. PMID:26393641

  18. The Methodology of Data Envelopment Analysis.

    ERIC Educational Resources Information Center

    Sexton, Thomas R.

    1986-01-01

    The methodology of data envelopment analysis, (DEA) a linear programming-based method, is described. Other procedures often used for measuring relative productive efficiency are discussed in relation to DEA, including ratio analysis and multiple regression analysis. The DEA technique is graphically illustrated for only two inputs and one output.…

  19. Diffusive heat blanketing envelopes of neutron stars

    NASA Astrophysics Data System (ADS)

    Beznogov, M. V.; Potekhin, A. Y.; Yakovlev, D. G.

    2016-06-01

    We construct new models of outer heat blanketing envelopes of neutron stars composed of binary ion mixtures (H-He, He-C, C-Fe) in and out of diffusive equilibrium. To this aim, we generalize our previous work on diffusion of ions in isothermal gaseous or Coulomb liquid plasmas to handle non-isothermal systems. We calculate the relations between the effective surface temperature Ts and the temperature Tb at the bottom of heat blanketing envelopes (at a density ρb ˜ 108 - 1010 g cm-3) for diffusively equilibrated and non-equilibrated distributions of ion species at different masses ΔM of lighter ions in the envelope. Our principal result is that the Ts-Tb relations are fairly insensitive to detailed distribution of ion fractions over the envelope (diffusively equilibrated or not) and depend almost solely on ΔM. The obtained relations are approximated by analytic expressions which are convenient for modelling the evolution of neutron stars.

  20. Thermal Damage to Chloroplast Envelope Membranes 1

    PubMed Central

    McCain, Douglas C.; Croxdale, Judith; Markley, John L.

    1989-01-01

    Nuclear magnetic resonance was used to detect thermal injury to chloroplasts in vivo. A lesion occurs in the chloroplast envelope membrane at temperatures between 53°C and 57°C, depending on species, leaf condition, and heating rate. The injury is associated with a sudden loss of water from the chloroplast. PMID:16666815