A modified holographic dark energy model with infrared infinite extra dimension(s)
NASA Astrophysics Data System (ADS)
Gong, Yungui; Li, Tianjun
2010-01-01
We propose a modified holographic dark energy (MHDE) model with the Hubble scale as the infrared (IR) cutoff. Introducing the infinite extra dimension(s) at very large distance scale, we consider the black hole mass in higher dimensions as the ultraviolet cutoff. Thus, we can probe the effects of the IR infinite extra dimension(s). As a concrete example, we consider the Dvali-Gabadadze-Porrati (DGP) model and its generalization. We find that the DGP model is dual to the MHDE model in five dimensions, and the ΛCDM model is dual to the MHDE model in six dimensions. Fitting the MHDE model to the observational data, we obtain that Ωm0=0.269-0.027+0.030, Ωk0=0.003-0.012+0.011, and the number of the spatial dimensions is N=4.78-0.44+0.68. The best fit value of N implies that there might exist two IR infinite extra dimensions.
Results of On-Orbit Testing of an Extra-Vehicular Infrared Camera Inspection System
NASA Technical Reports Server (NTRS)
Howell, Patricia A.; Cramer, K. Elliott
2007-01-01
This paper will discuss an infrared camera inspection system that has been developed to allow astronauts to demonstrate the ability to inspect reinforced carbon-carbon (RCC) components on the space shuttle as part of extra-vehicular activities (EVA) while in orbit. Presented will be the performance of the EVA camera system coupled with solar heating for inspection of damaged RCC specimens and NDE standards. The data presented was acquired during space shuttle flights STS-121 and STS-115 as well during a staged EVA from the ISS. The EVA camera system was able to detect flatbottom holes as small as 2.54cm in diameter with 25% material loss. Results obtained are shown to be comparable to ground-based thermal inspections performed in the laboratory using the same camera and simulated solar heating. Data on both the time history of the specimen temperature and the ability of the inspection system to image defects due to impact will likewise be presented.
Visible and near-infrared spectral signatures for adulteration assessment of extra virgin olive oil
NASA Astrophysics Data System (ADS)
Mignani, A. G.; Ciaccheri, L.; Ottevaere, H.; Thienpont, H.; Conte, L.; Marega, M.; Cichelli, A.; Attilio, C.; Cimato, A.
2010-04-01
Because of its high price, the extra virgin olive oil is frequently target for adulteration with lower quality oils. This paper presents an innovative optical technique capable of quantifying the adulteration of extra virgin olive oil caused by lowergrade olive oils. It relies on spectral fingerprinting the test liquid by means of diffuse-light absorption spectroscopy carried out by optical fiber technology in the wide 400-1700 nm spectral range. Then, a smart multivariate processing of spectroscopic data is applied for immediate prediction of adulterant concentration.
DOE R&D Accomplishments Database
Nambu, Y.
1967-01-01
The main ingredients of the method of infinite multiplets consist of: 1) the use of wave functions with an infinite number of components for describing an infinite tower of discrete states of an isolated system (such as an atom, a nucleus, or a hadron), 2) the use of group theory, instead of dynamical considerations, in determining the properties of the wave functions.
Azizian, Hormoz; Mossoba, Magdi M; Fardin-Kia, Ali Reza; Delmonte, Pierluigi; Karunathilaka, Sanjeewa R; Kramer, John K G
2015-07-01
A new, rapid Fourier transform near infrared (FT-NIR) spectroscopic procedure is described to screen for the authenticity of extra virgin olive oils (EVOO) and to determine the kind and amount of an adulterant in EVOO. To screen EVOO, a partial least squares (PLS1) calibration model was developed to estimate a newly created FT-NIR index based mainly on the relative intensities of two unique carbonyl overtone absorptions in the FT-NIR spectra of EVOO and other mixtures attributed to volatile (5280 cm(-1)) and non-volatile (5180 cm(-1)) components. Spectra were also used to predict the fatty acid (FA) composition of EVOO or samples spiked with an adulterant using previously developed PLS1 calibration models. Some adulterated mixtures could be identified provided the FA profile was sufficiently different from those of EVOO. To identify the type and determine the quantity of an adulterant, gravimetric mixtures were prepared by spiking EVOO with different concentrations of each adulterant. Based on FT-NIR spectra, four PLS1 calibration models were developed for four specific groups of adulterants, each with a characteristic FA composition. Using these different PLS1 calibration models for prediction, plots of predicted vs. gravimetric concentrations of an adulterant in EVOO yielded linear regression functions with four unique sets of slopes, one for each group of adulterants. Four corresponding slope rules were defined that allowed for the determination of the nature and concentration of an adulterant in EVOO products by applying these four calibration models. The standard addition technique was used for confirmation. PMID:26050093
Infinitely Large New Dimensions
Arkani-Hamed, Nima; Dimopoulos, Savas; Dvali, Gia; Kaloper, Nemanja
1999-07-29
We construct intersecting brane configurations in Anti-de-Sitter space localizing gravity to the intersection region, with any number n of extra dimensions. This allows us to construct two kinds of theories with infinitely large new dimensions, TeV scale quantum gravity and sub-millimeter deviations from Newton's Law. The effective 4D Planck scale M{sub Pl} is determined in terms of the fundamental Planck scale M{sub *} and the AdS radius of curvature L via the familiar relation M{sub Pl}{sup 2} {approx} M{sub *}{sup 2+n} L{sup n}; L acts as an effective radius of compactification for gravity on the intersection. Taking M{sub *} {approx} TeV and L {approx} sub-mm reproduces the phenomenology of theories with large extra dimensions. Alternately, taking M{sub *} {approx} L{sup -1} {approx} M{sub Pl}, and placing our 3-brane a distance {approx} 100M{sub Pl}{sup -1} away from the intersection gives us a theory with an exponential determination of the Weak/Planck hierarchy.
Unification and Infinite Series
ERIC Educational Resources Information Center
Leyendekkers, J. V.; Shannon, A. G.
2008-01-01
Some infinite series are analysed on the basis of the hypergeometric function and integer structure and modular rings. The resulting generalized functions are compared with differentiation of the "mother" series. (Contains 1 table.)
Diphoton resonance from a warped extra dimension
NASA Astrophysics Data System (ADS)
Bauer, Martin; Hörner, Clara; Neubert, Matthias
2016-07-01
We argue that extensions of the Standard Model (SM) with a warped extra dimension, which successfully address the hierarchy and flavor problems of elementary particle physics, can provide an elegant explanation of the 750 GeV diphoton excess recently reported by ATLAS and CMS. A gauge-singlet bulk scalar with {O} (1) couplings to fermions is identified as the new resonance S, and the vector-like Kaluza-Klein excitations of the SM quarks and leptons mediate its loop-induced couplings to photons and gluons. The electroweak gauge symmetry almost unambiguously dictates the bulk matter content and hence the hierarchies of the Sto γ γ, W W,ZZ,Zγ, toverline{t} and dijet decay rates. We find that the S → Zγ decay mode is strongly suppressed, such that Br( S → Zγ) /Br( S → γγ) < 0 .1. The hierarchy problem for the new scalar boson is solved in analogy with the Higgs boson by localizing it near the infrared brane. The infinite sums over the Kaluza-Klein towers of fermion states converge and can be calculated in closed form with a remarkably simple result. Reproducing the observed pp → S → γγ signal requires Kaluza-Klein masses in the multi-TeV range, consistent with bounds from flavor physics and electroweak precision observables.
ERIC Educational Resources Information Center
Wanko, Jeffrey J.
2009-01-01
This article provides a historical context for the debate between Georg Cantor and Leopold Kronecker regarding the cardinality of different infinities and incorporates the short story "Welcome to the Hotel Infinity," which uses the analogy of a hotel with an infinite number of rooms to help explain this concept. Wanko makes use of this history and…
NASA Astrophysics Data System (ADS)
Monreal-Ibero, A.; Arribas, S.; Colina, L.; Rodríguez-Zaurín, J.; Alonso-Herrero, A.; García-Marín, M.
2010-07-01
Context. Luminous infrared galaxies (LIRGs) are an important class of objects in the low-z universe bridging the gap between normal spirals and the strongly interacting and starbursting ultraluminous infrared galaxies (ULIRGs). Since a large fraction of the stars in the Universe have been formed in these objects, LIRGs are also relevant in a high-z context. Studies of the two-dimensional physical properties of LIRGs are still lacking. Aims: We aim to understand the nature and origin of the ionization mechanisms operating in the extra-nuclear regions of LIRGs as a function of the interaction phase and infrared luminosity. Methods: This study uses optical integral field spectroscopy (IFS) data obtained with VIMOS. Our analysis is based on over 25 300 spectra of 32 LIRGs covering all types of morphologies (isolated galaxies, interacting pairs, and advanced mergers), and the entire 1011-1012 L⊙ infrared luminosity range. Results: We found strong evidence for shock ionization, with a clear trend with the dynamical status of the system. Specifically, we quantified the variation with interaction phase of several line ratios indicative of the excitation degree. While the [N ii]λ6584/Hα ratio does not show any significant change, the [S ii]λλ6717,6731/Hα and [O i]λ6300/Hα ratios are higher for more advanced interaction stages. Velocity dispersions are higher than in normal spirals and increase with the interaction class (medians of 37, 46, and 51 km s-1 for class 0-2, respectively). We constrained the main mechanisms causing the ionization in the extra-nuclear regions (typically for distances ranging from ~0.2-2.1 kpc to ~0.9-13.2 kpc) using diagnostic diagrams. Isolated systems are mainly consistent with ionization caused by young stars. Large fractions of the extra-nuclear regions in interacting pairs and more advanced mergers are consistent with ionization caused by shocks of vs ⪉ 200 km s-1. This is supported by the relation between the excitation degree and
NASA Astrophysics Data System (ADS)
Vollmer, M.
2013-11-01
'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the
NASA Astrophysics Data System (ADS)
Lenci, Marco
2010-09-01
In the context of the long-standing issue of mixing in infinite ergodic theory, we introduce the idea of mixing for observables possessing an infinite-volume average. The idea is borrowed from statistical mechanics and appears to be relevant, at least for extended systems with a direct physical interpretation. We discuss the pros and cons of a few mathematical definitions that can be devised, testing them on a prototypical class of infinite measure-preserving dynamical systems, namely, the random walks.
Students' Conception of Infinite Series
ERIC Educational Resources Information Center
Martinez-Planell, Rafael; Gonzalez, Ana Carmen; DiCristina, Gladys; Acevedo, Vanessa
2012-01-01
This is a report of a study of students' understanding of infinite series. It has a three-fold purpose: to show that students may construct two essentially different notions of infinite series, to show that one of the constructions is particularly difficult for students, and to examine the way in which these two different constructions may be…
NASA Technical Reports Server (NTRS)
1979-01-01
A sensor system for the direct detection of extrasolar planets from an Earth orbit is evaluated: a spinning, infrared interferometer (IRIS). It is shuttle deployed, free flying, requires no on-orbit assembly and no reservicing over a design life of five years. The sensor concept and the mission objectives are reviewed, and the performance characteristics of a baseline sensor for standard observation conditions are derived. A baseline sensor design is given and the enabling technology discussed. Cost and weight estimates are performed; and a schedule for an IRIS program including technology development and assessment of risk are given. Finally, the sensor is compared with the apodized visual telescope sensor (APOTS) proposed for the same mission. The major conclusions are: that with moderate to strong technology advances, particularly in the fields of long life cryogenics, dynamical control, mirror manufacturing, and optical alignment, the detection of a Jupiter like planet around a Sunlike star at a distance of 30 light years is feasible, with a 3 meter aperture and an observation time of 1 hour. By contrast, major and possibly unlikely breakthroughs in mirror technology are required for APOTS to match this performance.
Infinite dimensional quantum information geometry
NASA Astrophysics Data System (ADS)
Grasselli, Matheus R.
2001-02-01
We present the construction of an infinite dimensional Banach manifold of quantum mechanical states on a Hilbert space H using different types of small perturbations of a given Hamiltonian H0. We provide the manifold with a flat connection, called the exponential connection, and comment on the possibility of introducing the dual mixture connection
Decoherence in infinite quantum systems
Blanchard, Philippe; Hellmich, Mario
2012-09-01
We review and discuss a notion of decoherence formulated in the algebraic framework of quantum physics. Besides presenting some sufficient conditions for the appearance of decoherence in the case of Markovian time evolutions we provide an overview over possible decoherence scenarios. The framework for decoherence we establish is sufficiently general to accommodate quantum systems with infinitely many degrees of freedom.
Word learning under infinite uncertainty.
Blythe, Richard A; Smith, Andrew D M; Smith, Kenny
2016-06-01
Language learners must learn the meanings of many thousands of words, despite those words occurring in complex environments in which infinitely many meanings might be inferred by the learner as a word's true meaning. This problem of infinite referential uncertainty is often attributed to Willard Van Orman Quine. We provide a mathematical formalisation of an ideal cross-situational learner attempting to learn under infinite referential uncertainty, and identify conditions under which word learning is possible. As Quine's intuitions suggest, learning under infinite uncertainty is in fact possible, provided that learners have some means of ranking candidate word meanings in terms of their plausibility; furthermore, our analysis shows that this ranking could in fact be exceedingly weak, implying that constraints which allow learners to infer the plausibility of candidate word meanings could themselves be weak. This approach lifts the burden of explanation from 'smart' word learning constraints in learners, and suggests a programme of research into weak, unreliable, probabilistic constraints on the inference of word meaning in real word learners. PMID:26927884
Introduction to Extra Dimensions
Rizzo, Thomas G.; /SLAC
2010-04-29
Extra dimensions provide a very useful tool in addressing a number of the fundamental problems faced by the Standard Model. The following provides a very basic introduction to this very broad subject area as given at the VIII School of the Gravitational and Mathematical Physics Division of the Mexican Physical Society in December 2009. Some prospects for extra dimensional searches at the 7 TeV LHC with {approx}1 fb{sup -1} of integrated luminosity are provided.
An Infinite Restricted Boltzmann Machine.
Côté, Marc-Alexandre; Larochelle, Hugo
2016-07-01
We present a mathematical construction for the restricted Boltzmann machine (RBM) that does not require specifying the number of hidden units. In fact, the hidden layer size is adaptive and can grow during training. This is obtained by first extending the RBM to be sensitive to the ordering of its hidden units. Then, with a carefully chosen definition of the energy function, we show that the limit of infinitely many hidden units is well defined. As with RBM, approximate maximum likelihood training can be performed, resulting in an algorithm that naturally and adaptively adds trained hidden units during learning. We empirically study the behavior of this infinite RBM, showing that its performance is competitive to that of the RBM, while not requiring the tuning of a hidden layer size. PMID:27171012
Logic of infinite quantum systems
NASA Astrophysics Data System (ADS)
Mundici, Daniele
1993-10-01
Limits of sequences of finite-dimensional (AF) C *-algebras, such as the CAR algebra for the ideal Fermi gas, are a standard mathematical tool to describe quantum statistical systems arising as thermodynamic limits of finite spin systems. Only in the infinite-volume limit one can, for instance, describe phase transitions as singularities in the thermodynamic potentials, and handle the proliferation of physically inequivalent Hilbert space representations of a system with infinitely many degrees of freedom. As is well known, commutative AF C *-algebras correspond to countable Boolean algebras, i.e., algebras of propositions in the classical two-valued calculus. We investigate the noncommutative logic properties of general AF C *-algebras, and their corresponding systems. We stress the interplay between Gödel incompleteness and quotient structures in the light of the “nature does not have ideals” program, stating that there are no quotient structures in physics. We interpret AF C *-algebras as algebras of the infinite-valued calculus of Lukasiewicz, i.e., algebras of propositions in Ulam's “ twenty questions” game with lies.
Teleportation schemes in infinite dimensional Hilbert spaces
Fichtner, Karl-Heinz; Freudenberg, Wolfgang; Ohya, Masanori
2005-10-01
The success of quantum mechanics is due to the discovery that nature is described in infinite dimension Hilbert spaces, so that it is desirable to demonstrate the quantum teleportation process in a certain infinite dimensional Hilbert space. We describe the teleportation process in an infinite dimensional Hilbert space by giving simple examples.
Extra Dimensions and ``Branes''
NASA Astrophysics Data System (ADS)
Sundrum, Raman
2011-04-01
We do not yet know the nature of fundamental physics above the weak scale, but we are about to probe it this decade. It may come in the form of a few new weakly-coupled particles, captured by ordinary Feynman diagrams in standard spacetime, or alternatively in the form of large ``towers'' of new elementary or composite states, requiring a different set of concepts and analytic tools. Extra spatial dimensions provide the simplest, but very rich, class of such possibilities. I will explain how extra-dimensions can provide an elegant and intuitive geometrization of subtle physics, in particular flowing from the powerful AdS/CFT correspondence. This geometrization allows one to ``view'' central issues ranging from electroweak, grand unified, strongly-coupled, flavor, supersymmetry, or collider physics, in terms of the overlap of extra-dimensional wavefunctions, the curvature (``warping'') of the higher dimensional spacetime, and ``branes'' (3-dimensional defects). I will illustrate the kind of physics and experimental signals that flow from the most plausible extra-dimensional scenarios.
Sparse Bayesian infinite factor models
Bhattacharya, A.; Dunson, D. B.
2011-01-01
We focus on sparse modelling of high-dimensional covariance matrices using Bayesian latent factor models. We propose a multiplicative gamma process shrinkage prior on the factor loadings which allows introduction of infinitely many factors, with the loadings increasingly shrunk towards zero as the column index increases. We use our prior on a parameter-expanded loading matrix to avoid the order dependence typical in factor analysis models and develop an efficient Gibbs sampler that scales well as data dimensionality increases. The gain in efficiency is achieved by the joint conjugacy property of the proposed prior, which allows block updating of the loadings matrix. We propose an adaptive Gibbs sampler for automatically truncating the infinite loading matrix through selection of the number of important factors. Theoretical results are provided on the support of the prior and truncation approximation bounds. A fast algorithm is proposed to produce approximate Bayes estimates. Latent factor regression methods are developed for prediction and variable selection in applications with high-dimensional correlated predictors. Operating characteristics are assessed through simulation studies, and the approach is applied to predict survival times from gene expression data. PMID:23049129
Squashed entanglement in infinite dimensions
NASA Astrophysics Data System (ADS)
Shirokov, M. E.
2016-03-01
We analyse two possible definitions of the squashed entanglement in an infinite-dimensional bipartite system: direct translation of the finite-dimensional definition and its universal extension. It is shown that the both definitions produce the same lower semicontinuous entanglement measure possessing all basis properties of the squashed entanglement on the set of states having at least one finite marginal entropy. It is also shown that the second definition gives an adequate lower semicontinuous extension of this measure to all states of the infinite-dimensional bipartite system. A general condition relating continuity of the squashed entanglement to continuity of the quantum mutual information is proved and its corollaries are considered. Continuity bound for the squashed entanglement under the energy constraint on one subsystem is obtained by using the tight continuity bound for quantum conditional mutual information (proved in the Appendix by using Winter's technique). It is shown that the same continuity bound is valid for the entanglement of formation. As a result the asymptotic continuity of the both entanglement measures under the energy constraint on one subsystem is proved.
Unitarity violation in sequential neutrino mixing in a model of extra dimensions
Bhattacharya, Subhaditya; Dey, Paramita; Mukhopadhyaya, Biswarup
2009-10-01
We give the first demonstration of unitarity violation in the sequential neutrino mixing matrix in a scenario with extra compact spacelike dimensions. Gauge singlet neutrinos are assumed to propagate in one extra dimension, giving rise to an infinite tower of states in the effective four-dimensional theory. It is shown that this leads to small lepton-number violating entries in the neutrino mass matrix, which can violate unitarity on the order of 1%.
Isocurvature perturbations in extra radiation
Kawasaki, Masahiro; Miyamoto, Koichi; Nakayama, Kazunori; Sekiguchi, Toyokazu E-mail: miyamone@icrr.u-tokyo.ac.jp E-mail: oyokazu.sekiguchi@nagoya-u.jp
2012-02-01
Recent cosmological observations, including measurements of the CMB anisotropy and the primordial helium abundance, indicate the existence of an extra radiation component in the Universe beyond the standard three neutrino species. In this paper we explore the possibility that the extra radiation has isocurvatrue fluctuations. A general formalism to evaluate isocurvature perturbations in the extra radiation is provided in the mixed inflaton-curvaton system, where the extra radiation is produced by the decay of both scalar fields. We also derive constraints on the abundance of the extra radiation and the amount of its isocurvature perturbation. Current observational data favors the existence of an extra radiation component, but does not indicate its having isocurvature perturbation. These constraints are applied to some particle physics motivated models. If future observations detect isocurvature perturbations in the extra radiation, it will give us a hint to the origin of the extra radiation.
The search for extra-terrestrial intelligence.
Drake, Frank
2011-02-13
Modern history of the search for extra-terrestrial intelligence is reviewed. The history of radio searches is discussed, as well as the major advances that have occurred in radio searches and prospects for new instruments and search strategies. Recent recognition that searches for optical and infrared signals make sense, and the reasons for this are described, as well as the equipment and special detection methods used in optical searches. The long-range future of the search for extra-terrestrial intelligence (SETI) is discussed in the context of the history of rapid change, on the cosmic and even the human time scale, of the paradigms guiding SETI searches. This suggests that SETI searches be conducted with a very open mind. PMID:21220287
Envisioning the Infinite by Projecting Finite Properties
ERIC Educational Resources Information Center
Ely, Robert
2011-01-01
We analyze interviews with 24 post-secondary students as they reason about infinite processes in the context of the tricky Tennis Ball Problem. By metaphorically projecting various properties from the finite states such as counting and indexing, participants envisioned widely varying final states for the infinite process. Depending on which…
Improving the Instruction of Infinite Series
ERIC Educational Resources Information Center
Lindaman, Brian; Gay, A. Susan
2012-01-01
Calculus instructors struggle to teach infinite series, and students have difficulty understanding series and related concepts. Four instructional strategies, prominently used during the calculus reform movement, were implemented during a 3-week unit on infinite series in one class of second-semester calculus students. A description of each…
Inspiring Examples in Rearrangements of Infinite Products
ERIC Educational Resources Information Center
Ramasinghe, W.
2007-01-01
It is well known that simple examples are really encouraging in the understanding of rearrangements of infinite series. In this paper a similar role is played by simple examples in the case of infinite products. Iterated products of double products seem to have a similar spirit of rearrangements of products, although they are not the same.…
Orthogonality preserving infinite dimensional quadratic stochastic operators
Akın, Hasan; Mukhamedov, Farrukh
2015-09-18
In the present paper, we consider a notion of orthogonal preserving nonlinear operators. We introduce π-Volterra quadratic operators finite and infinite dimensional settings. It is proved that any orthogonal preserving quadratic operator on finite dimensional simplex is π-Volterra quadratic operator. In infinite dimensional setting, we describe all π-Volterra operators in terms orthogonal preserving operators.
Understanding the Behaviour of Infinite Ladder Circuits
ERIC Educational Resources Information Center
Ucak, C.; Yegin, K.
2008-01-01
Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…
Are There Infinite Irrigation Trees?
NASA Astrophysics Data System (ADS)
Bernot, M.; Caselles, V.; Morel, J. M.
2006-08-01
In many natural or artificial flow systems, a fluid flow network succeeds in irrigating every point of a volume from a source. Examples are the blood vessels, the bronchial tree and many irrigation and draining systems. Such systems have raised recently a lot of interest and some attempts have been made to formalize their description, as a finite tree of tubes, and their scaling laws [25], [26]. In contrast, several mathematical models [5], [22], [10], propose an idealization of these irrigation trees, where a countable set of tubes irrigates any point of a volume with positive Lebesgue measure. There is no geometric obstruction to this infinitesimal model and general existence and structure theorems have been proved. As we show, there may instead be an energetic obstruction. Under Poiseuille law R(s) = s -2 for the resistance of tubes with section s, the dissipated power of a volume irrigating tree cannot be finite. In other terms, infinite irrigation trees seem to be impossible from the fluid mechanics viewpoint. This also implies that the usual principle analysis performed for the biological models needs not to impose a minimal size for the tubes of an irrigating tree; the existence of the minimal size can be proven from the only two obvious conditions for such irrigation trees, namely the Kirchhoff and Poiseuille laws.
Infinite sets and double binds.
Arden, M
1984-01-01
There have been many attempts to bring psychoanalytical theory up to date. This paper approaches the problem by discussing the work of Gregory Bateson and Ignacio Matte-Blanco, with particular reference to the use made by these authors of Russell's theory of logical types. Bateson's theory of the double bind and Matte-Blanco's bilogic are both based on concepts of logical typing. It is argued that the two theories can be linked by the idea that neurotic symptoms are based on category errors in thinking. Clinical material is presented from the analysis of a middle-aged woman. The intention is to demonstrate that the process of making interpretations can be thought of as revealing errors in thinking. Changes in the patient's inner world are then seen to be the result of clarifying childhood experiences based on category errors. Matte-Blanco's theory of bilogic and infinite experiences is a re-evaluation of the place of the primary process in mental life. It is suggested that a combination of bilogic and double bind theory provides a possibility of reformulating psychoanalytical theory. PMID:6544755
Where Infinite Spin Particles are Localizable
NASA Astrophysics Data System (ADS)
Longo, Roberto; Morinelli, Vincenzo; Rehren, Karl-Henning
2016-07-01
Particle states transforming in one of the infinite spin representations of the Poincaré group (as classified by E. Wigner) are consistent with fundamental physical principles, but local fields generating them from the vacuum state cannot exist. While it is known that infinite spin states localized in a spacelike cone are dense in the one-particle space, we show here that the subspace of states localized in any double cone is trivial. This implies that the free field theory associated with infinite spin has no observables localized in bounded regions. In an interacting theory, if the vacuum vector is cyclic for a double cone local algebra, then the theory does not contain infinite spin representations. We also prove that if a Doplicher-Haag-Roberts representation (localized in a double cone) of a local net is covariant under a unitary representation of the Poincaré group containing infinite spin, then it has infinite statistics. These results hold under the natural assumption of the Bisognano-Wichmann property, and we give a counter-example (with continuous particle degeneracy) without this property where the conclusions fail. Our results hold true in any spacetime dimension s + 1 where infinite spin representations exist, namely {s≥ 2}.
Phenomenology of Extra Dimensions
Hewett, J.L.; /SLAC
2006-11-07
If the structure of spacetime is different than that readily observed, gravitational physics, particle physics and cosmology are all immediately affected. The physics of extra dimensions offers new insights and solutions to fundamental questions arising in these fields. Novel ideas and frameworks are continuously born and evolved. They make use of string theoretical features and tools and they may reveal if and how the 11-dimensional string theory is relevant to our four-dimensional world. We have outlined some of the experimental observations in particle and gravitational physics as well as astrophysical and cosmological considerations that can constrain or confirm these scenarios. These developing ideas and the wide interdisciplinary experimental program that is charted out to investigate them mark a renewed effort to describe the dynamics behind spacetime. We look forward to the discovery of a higher dimensional spacetime.
Lyapunov exponents for infinite dimensional dynamical systems
NASA Technical Reports Server (NTRS)
Mhuiris, Nessan Mac Giolla
1987-01-01
Classically it was held that solutions to deterministic partial differential equations (i.e., ones with smooth coefficients and boundary data) could become random only through one mechanism, namely by the activation of more and more of the infinite number of degrees of freedom that are available to such a system. It is only recently that researchers have come to suspect that many infinite dimensional nonlinear systems may in fact possess finite dimensional chaotic attractors. Lyapunov exponents provide a tool for probing the nature of these attractors. This paper examines how these exponents might be measured for infinite dimensional systems.
Semi-infinite cohomology and string theory
Frenkel, I. B.; Garland, H.; Zuckerman, G. J.
1986-01-01
We develop the theory of semi-infinite cohomology of graded Lie algebras first introduced by Feigin. We show that the relative semi-infinite cohomology has a structure analogous to that of the de Rham cohomology in Kähler geometry. We prove a vanishing theorem for a special class of modules, and we apply our results to the case of the Virasoro algebra and the Fock module. In this case the zero cohomology is identified as the physical subspace of the Fock module and the no-ghost theorem follows. We reveal the profound relation of semi-infinite cohomology theory to the gauge-invariant free string theory constructed by Banks and Peskin. We then indicate the connection between gauge-invariant interacting string theories and the geometric realizations of the infinite-dimensional Lie algebras. PMID:16578792
Semi-infinite cohomology and string theory.
Frenkel, I B; Garland, H; Zuckerman, G J
1986-11-01
We develop the theory of semi-infinite cohomology of graded Lie algebras first introduced by Feigin. We show that the relative semi-infinite cohomology has a structure analogous to that of the de Rham cohomology in Kähler geometry. We prove a vanishing theorem for a special class of modules, and we apply our results to the case of the Virasoro algebra and the Fock module. In this case the zero cohomology is identified as the physical subspace of the Fock module and the no-ghost theorem follows. We reveal the profound relation of semi-infinite cohomology theory to the gauge-invariant free string theory constructed by Banks and Peskin. We then indicate the connection between gauge-invariant interacting string theories and the geometric realizations of the infinite-dimensional Lie algebras. PMID:16578792
Understanding the behaviour of infinite ladder circuits
NASA Astrophysics Data System (ADS)
Ucak, C.; Yegin, K.
2008-11-01
Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does not change when a new block of impedance is added. However, the impedance derived from this assumption may lead to incorrect conclusions if it is not treated carefully. Sometimes, in the literature, the input impedance behaviour of infinite ladder circuits is referred to as a paradox, leaving students and educators in doubt. This study intends to clarify this confusion and help to better comprehend the behaviour of the input impedance of infinite ladder circuits.
Seismic stability of gentle infinite slopes
Hadj-Hamou, T.; Kavazanjian, E.
1985-06-01
Deterministic and probabilistic analyses of the stability of gentle infinite slopes subject to seismically induced excess pore pressures and inertia forces are developed. In the deterministic analysis, classical equations for infinite slope stability are rewritten to explicitly include excess pore pressure and seismic acceleration. Equations for the factor of safety are developed that include these factors. In the probabilistic analysis, the seismic acceleration, excess pore pressure, and effective friction angle are considered random variables. Acceleration peaks are considered Rayleigh distributed. Excess pore pressure is predicted using a model that considers Rayleigh distributed shear stress peaks. The friction angle is modeled with a Beta distribution. Acceleration and pore pressure development within the gentle infinite slope are assumed the same as those in a horizontal deposit of the same average thicknesss. Finite element analyses are performed to investigate the limits of this assumption. Results from both analyses are compared to documented case histories of lateral spreading.
Rapalino, Otto; Smirniotopoulos, James G
2016-01-01
Extra-axial brain tumors are the most common adult intracranial neoplasms and encompass a broad spectrum of pathologic subtypes. Meningiomas are the most common extra-axial brain tumor (approximately one-third of all intracranial neoplasms) and typically present as slowly growing dural-based masses. Benign meningiomas are very common, and may occasionally be difficult to differentiate from more aggressive subtypes (i.e., atypical or malignant varieties) or other dural-based masses with more aggressive biologic behavior (e.g., hemangiopericytoma or dural-based metastases). Many neoplasms that typically affect the brain parenchyma (intra-axial), such as gliomas, may also present with primary or secondary extra-axial involvement. This chapter provides a general and concise overview of the common types of extra-axial tumors and their typical imaging features. PMID:27432671
Theory and experiment for infinite microstrip arrays
NASA Astrophysics Data System (ADS)
Wright, S. M.; Lo, Y. T.
1985-01-01
Microstrip antennas are well suited for use in large scanning arrays. To obtain greater bandwidth, it is useful to use thicker substrates, which can increase the effects of mutual coupling and lead to significant mismatch or blindness for certain scan angles. Using an infinite array formulation, the impedance of a single element in an infinite array environment was solved with the method of moments. Mutual coupling is built into the solution, and the presence of surface waves is accounted for by using the periodic Green's function for the grounded dielectric substrate. Blindness in arrays of microstrip dipoles on various substrates, both with and without radomes is demonstrated.
The Extra-Zodiacal Explorer (EZE)
NASA Astrophysics Data System (ADS)
Greenhouse, Matthew A.; Benson, S. W.; Fixsen, D. J.; Gardner, J. P.; Kruk, J. W.; Thronson, H. A.
2012-01-01
We describe a mission architecture study designed to substantially increase the potential science performance of the NASA SMD Astrophysics Explorer Program for all AO offerors working within the near-UV to far-infrared spectrum. We have demonstrated that augmentation of Falcon 9 Explorer launch services with a Solar Electric Propulsion (SEP) stage can deliver a 700 kg science observatory payload to an extra-Zodiacal orbit. This new capability enables up to 10X increased photometric sensitivity and 150X increased observing speed relative to a Sun-Earth L2 or Earth-trailing orbit with no increase in telescope aperture. All enabling SEP stage technologies for this launch service augmentation have reached sufficient readiness (TRL-6) for Explorer Program application in conjunction with the Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach extra-zodiacal orbit will allow this small payload program to rival the science performance of much larger long development time systems; thus, providing a means to realize major science objectives while increasing the SMD Astrophysics portfolio diversity and resiliency to external budget pressure. The SEP technology employed in this study has applicability to SMD Planetary competed missions and aligns with NASA in-space propulsion technology road map objectives and associated flight demonstration planning.
Efficient analysis for infinite microstrip dipole arrays
NASA Astrophysics Data System (ADS)
Wright, S. M.; Lo, Y. T.
1983-11-01
A moment method analysis of infinite microstrip dipole arrays which uses an efficient technique to evaluate the generalized impedance matrix is described. A particularly simple formulation is obtained through the use of the periodic Green function. Results for the reflection coefficient magnitude against scan angle are given for a typical array.
Stress on Second Conjugation Infinitives in Italian.
ERIC Educational Resources Information Center
Davis, Stuart; And Others
1987-01-01
Reviews the limited amount of research regarding ways in which primary stress is assigned to second conjugation infinitives in Italian and then proposes a new perspective taking into consideration root vowels, root-final consonants, syllable onset, monosyllabic vs. polysyllabic roots, and canonical form. (CB)
Infinite Sums of M-Bonacci Numbers
ERIC Educational Resources Information Center
A-iru, Muniru A.
2009-01-01
In this note, we construct infinite series using M-bonacci numbers in a manner similar to that used in previous studies and investigate the convergence of the series to an integer. Our results generalize the ones obtained for Fibonacci numbers.
On infinite-dimensional state spaces
Fritz, Tobias
2013-05-15
It is well known that the canonical commutation relation [x, p]=i can be realized only on an infinite-dimensional Hilbert space. While any finite set of experimental data can also be explained in terms of a finite-dimensional Hilbert space by approximating the commutation relation, Occam's razor prefers the infinite-dimensional model in which [x, p]=i holds on the nose. This reasoning one will necessarily have to make in any approach which tries to detect the infinite-dimensionality. One drawback of using the canonical commutation relation for this purpose is that it has unclear operational meaning. Here, we identify an operationally well-defined context from which an analogous conclusion can be drawn: if two unitary transformations U, V on a quantum system satisfy the relation V{sup -1}U{sup 2}V=U{sup 3}, then finite-dimensionality entails the relation UV{sup -1}UV=V{sup -1}UVU; this implication strongly fails in some infinite-dimensional realizations. This is a result from combinatorial group theory for which we give a new proof. This proof adapts to the consideration of cases where the assumed relation V{sup -1}U{sup 2}V=U{sup 3} holds only up to {epsilon} and then yields a lower bound on the dimension.
On infinite-dimensional state spaces
NASA Astrophysics Data System (ADS)
Fritz, Tobias
2013-05-01
It is well known that the canonical commutation relation [x, p] = i can be realized only on an infinite-dimensional Hilbert space. While any finite set of experimental data can also be explained in terms of a finite-dimensional Hilbert space by approximating the commutation relation, Occam's razor prefers the infinite-dimensional model in which [x, p] = i holds on the nose. This reasoning one will necessarily have to make in any approach which tries to detect the infinite-dimensionality. One drawback of using the canonical commutation relation for this purpose is that it has unclear operational meaning. Here, we identify an operationally well-defined context from which an analogous conclusion can be drawn: if two unitary transformations U, V on a quantum system satisfy the relation V-1U2V = U3, then finite-dimensionality entails the relation UV-1UV = V-1UVU; this implication strongly fails in some infinite-dimensional realizations. This is a result from combinatorial group theory for which we give a new proof. This proof adapts to the consideration of cases where the assumed relation V-1U2V = U3 holds only up to ɛ and then yields a lower bound on the dimension.
A Planar Calculus for Infinite Index Subfactors
NASA Astrophysics Data System (ADS)
Penneys, David
2013-05-01
We develop an analog of Jones' planar calculus for II 1-factor bimodules with arbitrary left and right von Neumann dimension. We generalize to bimodules Burns' results on rotations and extremality for infinite index subfactors. These results are obtained without Jones' basic construction and the resulting Jones projections.
Semi-Infinite Cohomology of Loop Spaces
NASA Astrophysics Data System (ADS)
Shutler, Paul Maurice Edmund
Available from UMI in association with The British Library. Requires signed TDF. This thesis attempts to construct a de Rham model for the Floer homology of the space of free loops on a symplectic manifold. It derives its inspiration principally from the work of Witten on topological quantum field theories. Chapter 1 consist of a review of background material followed by a number of elementary results. It is seen how Floer homology should naturally be representable by a semi-infinite generalisation of the ordinary de Rham theory associated to a manifold. In Chapter 2 the main attempt at constructing such a semi-infinite theory is made by defining an exterior derivative. Two different kinds of divergences are encountered and resolved. A suitable space of semi-infinite forms is constructed and some remarks are made about the likelihood that this model captures the Floer homology. In Chapter 3 the obstruction to the existence of a chiral factorisation of the bundle of fermionic Fock spaces over the loop space of the two-sphere is computed. For this purpose the ordinary cohomology ring of the loop space is calculated, also the action of the deck transformation on the cohomology of the simply connected covering space. In Chapter 4 the supersymmetric path integral approach to quantising topological field theories is developed formally. The semi-infinite dimensionality of the differential forms involved emerges naturally. The Floer homology of loop space is shown to be a ring. Its structure is calculated for the simple case of complex projective space. Chapter 5 concludes the thesis with some remarks about the action of the super-Virasoro algebra on the space of ordinary and semi-infinite differential forms respectively. Two short appendices are included describing a polynomial generating function for spherical harmonics and the spectrum of curl on vector fields on the three -sphere.
Wald Entropy for Ghost-Free, Infinite Derivative Theories of Gravity.
Conroy, Aindriú; Mazumdar, Anupam; Teimouri, Ali
2015-05-22
In this Letter, we demonstrate that the Wald entropy for any spherically symmetric black hole within an infinite derivative theory of gravity that is quadratic in curvature is determined solely by the area law. Thus, the infrared behavior of gravity is captured by the Einstein-Hilbert term, provided that the massless graviton remains the only propagating degree of freedom in the spacetime. PMID:26047217
Infinite bandwidth of a Mott-Hubbard insulator
NASA Astrophysics Data System (ADS)
Freericks, James; Cohn, Jeffrey; van Dongen, Peter; Krishnamurthy, Hulikal
The conventional viewpoint of the strongly correlated electron metal-insulator transition is that a single band splits into two upper and lower Hubbard bands at the metal-insulator transition. Much work has investigated whether this transition is continuous or discontinuous. Here we focus on another aspect and ask the question of whether there are additional upper and lower Hubbard bands, which stretch all the way out to infinity|leading to an infinite bandwidth for the Mott insulator. While we are not yet able to provide a rigorous proof of this result, we use exact diagonalization studies on small clusters to motivate the existence of these additional bands, and we discuss some different methods that might be utilized to provide a rigorous proof of this result. Even though the extra upper and lower Hubbard bands have very low total spectral weight, those states are expected to have extremely long lifetimes, leading to a nontrivial contribution to the transport density of states for dc transport and modifying the high temperature limit for the electrical resistivity. JKF supported by the Department of Energy, Office of Basic Energy Sciences, under Grant No. DE-FG02-08ER46542, and by the McDevitt bequest at Georgetown University. HRK supported by the Indian Science Foundation.
NASA Astrophysics Data System (ADS)
Bufetov, A. I.
2016-04-01
The second paper in this series is devoted to the convergence of sequences of infinite determinantal measures, understood as the convergence of sequences of the corresponding finite determinantal measures. Besides the weak topology in the space of probability measures on the space of configurations, we also consider the natural immersion (defined almost surely with respect to the infinite Bessel process) of the space of configurations into the space of finite measures on the half-line, which induces a weak topology in the space of finite measures on the space of finite measures on the half-line. The main results of the present paper are sufficient conditions for the tightness of families and the convergence of sequences of induced determinantal processes as well as for the convergence of processes corresponding to finite-rank perturbations of operators.
History of the Infinitely Small and the Infinitely Large in Calculus.
ERIC Educational Resources Information Center
Kleiner, Israel
2001-01-01
Considers examples of aspects of the infinitely small and large as they unfolded in the history of calculus from the 17th through the 20th centuries. Presents didactic observations at relevant places in the historical account. (Author/MM)
Collider searches for extra dimensions
Landsberg, Greg; /Brown U.
2004-12-01
Searches for extra spatial dimensions remain among the most popular new directions in our quest for physics beyond the Standard Model. High-energy collider experiments of the current decade should be able to find an ultimate answer to the question of their existence in a variety of models. Until the start of the LHC in a few years, the Tevatron will remain the key player in this quest. In this paper, we review the most recent results from the Tevatron on searches for large, TeV{sup -1}-size, and Randall-Sundrum extra spatial dimensions, which have reached a new level of sensitivity and currently probe the parameter space beyond the existing constraints. While no evidence for the existence of extra dimensions has been found so far, an exciting discovery might be just steps away.
Scientific Visualization of Extra Dimensions
NASA Astrophysics Data System (ADS)
Black, Don V.
2010-10-01
In the 21st Century, many theoretical physicists claim that higher dimensions may indeed exist. Arkani-Hamed, Dimopoulos, & Dvali (ADD) and Randall-Sundrum (RS), in addition to Kaluza-Klein (KK) and M-string theorists, have introduced reasonable explanations for the existence of heretofore ``invisible'' higher dimensions. Whether or not these extra dimensions actually exist is irrelevant to their contributions to the visionary conceptualization associated with novel and improved mathematical and physical analysis. Envisioning extra dimensions beyond the three of common experience is a daunting challenge for three dimensional observers. Intuition relies on experience gained in a three dimensional environment. Gaining experience with virtual four dimensional objects and virtual three manifolds in four-space on a personal computer may provide the basis for an intuitive grasp of four dimensions. This presentation is a video ``outtake'' of the author's research into ``Visualizing Extra Spatial Dimensions'' at the University of California at Irvine.
Entanglement convertibility for infinite-dimensional pure bipartite states
Owari, Masaki; Matsumoto, Keiji; Murao, Mio
2004-11-01
It is shown that the order property of pure bipartite states under stochastic local operations and classical communications (SLOCC) changes radically when dimensionality shifts from finite to infinite. In contrast to finite-dimensional systems where there is no pure incomparable state, the existence of infinitely many mutually SLOCC incomparable states is shown for infinite-dimensional systems even under the bounded energy and finite information exchange condition. These results show that the effect of the infinite dimensionality of Hilbert space, the 'infinite workspace' property, remains even in physically relevant infinite-dimensional systems.
Survival of scalar zero modes in warped extra dimensions
George, Damien P.
2011-05-15
Models with an extra dimension generally contain background scalar fields in a nontrivial configuration, whose stability must be ensured. With gravity present, the extra dimension is warped by the scalars, and the spin-0 degrees of freedom in the metric mix with the scalar perturbations. Where possible, we formally solve the coupled Schroedinger equations for the zero modes of these spin-0 perturbations. When specializing to the case of two scalars with a potential generated by a superpotential, we are able to fully solve the system. We show how these zero modes can be used to construct a solution matrix, whose eigenvalues tell whether a normalizable zero mode exists, and how many negative mass modes exist. These facts are crucial in determining stability of the corresponding background configuration. We provide examples of the general analysis for domain-wall models of an infinite extra dimension and domain-wall soft-wall models. For five-dimensional models with two scalars constructed using a superpotential, we show that a normalizable zero mode survives, even in the presence of warped gravity. Such models, which are widely used in the literature, are therefore phenomenologically unacceptable.
2.5D Finite/infinite Element Approach for Simulating Train-Induced Ground Vibrations
NASA Astrophysics Data System (ADS)
Yang, Y. B.; Hung, H. H.; Kao, J. C.
2010-05-01
The 2.5D finite/infinite element approach for simulating the ground vibrations by surface or underground moving trains will be briefly summarized in this paper. By assuming the soils to be uniform along the direction of the railway, only a two-dimensional profile of the soil perpendicular to the railway need be considered in the modeling. Besides the two in-plane degrees of freedom (DOFs) per node conventionally used for plane strain elements, an extra DOF is introduced to account for the out-of-plane wave transmission. The profile of the half-space is divided into a near field and a semi-infinite far field. The near field containing the train loads and irregular structures is simulated by the finite elements, while the far field covering the soils with infinite boundary by the infinite elements, by which due account is taken of the radiation effects for the moving loads. Enhanced by the automated mesh expansion procedure proposed previously by the writers, the far field impedances for all the lower frequencies are generated repetitively from the mesh created for the highest frequency considered. Finally, incorporated with a proposed load generation mechanism that takes the rail irregularity and dynamic properties of trains into account, an illustrative case study was performed. This paper investigates the vibration isolation effect of the elastic foundation that separates the concrete slab track from the underlying soil or tunnel structure. In addition, the advantage of the 2.5D approach was clearly demonstrated in that the three-dimensional wave propagation effect can be virtually captured using a two-dimensional finite/infinite element mesh. Compared with the conventional 3D approach, the present approach appears to be simple, efficient and generally accurate.
A Stochastic Tikhonov Theorem in Infinite Dimensions
Buckdahn, Rainer Guatteri, Giuseppina
2006-03-15
The present paper studies the problem of singular perturbation in the infinite-dimensional framework and gives a Hilbert-space-valued stochastic version of the Tikhonov theorem. We consider a nonlinear system of Hilbert-space-valued equations for a 'slow' and a 'fast' variable; the system is strongly coupled and driven by linear unbounded operators generating a C{sub 0}-semigroup and independent cylindrical Brownian motions. Under well-established assumptions to guarantee the existence and uniqueness of mild solutions, we deduce the required stability of the system from a dissipativity condition on the drift of the fast variable. We avoid differentiability assumptions on the coefficients which would be unnatural in the infinite-dimensional framework.
Quark ensembles with the infinite correlation length
Zinov’ev, G. M.; Molodtsov, S. V.
2015-01-15
A number of exactly integrable (quark) models of quantum field theory with the infinite correlation length have been considered. It has been shown that the standard vacuum quark ensemble—Dirac sea (in the case of the space-time dimension higher than three)—is unstable because of the strong degeneracy of a state, which is due to the character of the energy distribution. When the momentum cutoff parameter tends to infinity, the distribution becomes infinitely narrow, leading to large (unlimited) fluctuations. Various vacuum ensembles—Dirac sea, neutral ensemble, color superconductor, and BCS state—have been compared. In the case of the color interaction between quarks, the BCS state has been certainly chosen as the ground state of the quark ensemble.
Infinitely many singular interactions on noncompact manifolds
Kaynak, Burak Tevfik Turgut, O. Teoman
2015-05-15
We show that the ground state energy is bounded from below when there are infinitely many attractive delta function potentials placed in arbitrary locations, while all being separated at least by a minimum distance, on two dimensional non-compact manifold. To facilitate the reading of the paper, we first present the arguments in the setting of Cartan–Hadamard manifolds and then subsequently discuss the general case. For this purpose, we employ the heat kernel techniques as well as some comparison theorems of Riemannian geometry, thus generalizing the arguments in the flat case following the approach presented in Albeverio et al. (2004). - Highlights: • Schrödinger-operator for infinitely many singular interactions on noncompact manifolds. • Proof of the finiteness of the ground-state energy.
NASA Technical Reports Server (NTRS)
1979-01-01
The heating units shown in the accompanying photos are Panelbloc infrared heaters, energy savers which burn little fuel in relation to their effective heat output. Produced by Bettcher Manufacturing Corporation, Cleveland, Ohio, Panelblocs are applicable to industrial or other facilities which have ceilings more than 12 feet high, such as those pictured: at left the Bare Hills Tennis Club, Baltimore, Maryland and at right, CVA Lincoln- Mercury, Gaithersburg, Maryland. The heaters are mounted high above the floor and they radiate infrared energy downward. Panelblocs do not waste energy by warming the surrounding air. Instead, they beam invisible heat rays directly to objects which absorb the radiation- people, floors, machinery and other plant equipment. All these objects in turn re-radiate the energy to the air. A key element in the Panelbloc design is a coating applied to the aluminized steel outer surface of the heater. This coating must be corrosion resistant at high temperatures and it must have high "emissivity"-the ability of a surface to emit radiant energy. The Bettcher company formerly used a porcelain coating, but it caused a production problem. Bettcher did not have the capability to apply the material in its own plant, so the heaters had to be shipped out of state for porcelainizing, which entailed extra cost. Bettcher sought a coating which could meet the specifications yet be applied in its own facilities. The company asked The Knowledge Availability Systems Center, Pittsburgh, Pennsylvania, a NASA Industrial Applications Center (IAC), for a search of NASA's files
Variational Infinite Hidden Conditional Random Fields.
Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin
2015-09-01
Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of hidden states, which rids us not only of the necessity to specify a priori a fixed number of hidden states available but also of the problem of overfitting. Markov chain Monte Carlo (MCMC) sampling algorithms are often employed for inference in such models. However, convergence of such algorithms is rather difficult to verify, and as the complexity of the task at hand increases the computational cost of such algorithms often becomes prohibitive. These limitations can be overcome by variational techniques. In this paper, we present a generalized framework for infinite HCRF models, and a novel variational inference approach on a model based on coupled Dirichlet Process Mixtures, the HCRF-DPM. We show that the variational HCRF-DPM is able to converge to a correct number of represented hidden states, and performs as well as the best parametric HCRFs-chosen via cross-validation-for the difficult tasks of recognizing instances of agreement, disagreement, and pain in audiovisual sequences. PMID:26353136
NASA Technical Reports Server (NTRS)
Mushotzky, R.
2008-01-01
I will discuss how one can determine the origin of the 'extra entropy' in groups and clusters and the feedback needed in models of galaxy formation. I will stress the use of x-ray spectroscopy and imaging and the critical value that Con-X has in this regard.
On the principal and strictly particular solutions to infinite systems
NASA Astrophysics Data System (ADS)
Ivanova, O. F.; Pavlov, N. N.; Fedorov, F. M.
2016-03-01
The concepts of the principal solution to infinite systems of linear algebraic equations and the reduction method are defined more precisely. The principal solution, if it exists, is a strictly particular solution to the infinite system. If the reduction method is convergent, then it necessarily converges to Kramer's determinant; however, Kramer's determinant is not always a solution to the infinite system. To confirm the obtained results, analytical and numerical solutions of specific infinite system are considered.
The Bursting of the Dam (Infinite Sets, Countable and Otherwise).
ERIC Educational Resources Information Center
Francis, Richard L.
1992-01-01
Examines infinite sets and cardinality classifications of empty, finite but not empty, and infinite through discussions of numbers that fall into particular categories. Categories discussed include perfect numbers, Mersenne primes, pseudoprimes, and transcendental numbers. Discusses the Null Or Infinite Set Effect (NOISE) and infinitude resulting…
NASA Astrophysics Data System (ADS)
Bear, Ealeal; Soker, Noam
2016-07-01
We suggest that in the rare case of an Intermediate-Luminosity Optical Transient (ILOT) event, evaporation of extra-solar Kuiper belt objects (ExtraKBOs) at distances of d ≈ 500 – 10 000 AU from the ILOT can be detected. If the ILOT lasts for 1 month to a few years, enough dust might be ejected from the ExtraKBOs for the infrared (IR) emission to be detected. Because of the large distance of the ExtraKBOs, tens of years will pass before the ILOT wind disperses the dust. We suggest that after an ILOT outburst, there is a period of months to several years during which IR excess emission might hint at the existence of a Kuiper belt analog (ExtraK-Belt).
Infinite Maxwell fisheye inside a finite circle
NASA Astrophysics Data System (ADS)
Liu, Yangjié; Chen, Huanyang
2015-12-01
This manuscript proposes a two-dimensional heterogeneous imaging medium composed of an isotropic refractive index. We exploit conformal-mapping to transfer the full Maxwell fisheye into a finite circle. Unlike our previous design that requires a mirror of Zhukovski airfoil shape, this approach can work without a mirror, while offering a comparable imaging resolution. This medium may also be used as an isotropic gradient index lens to transform a light source inside it into two identical sources of null interference. A merit of this approach is reduction of the near-zero-index area from an infinite zone into a finite one, which shall ease its realization.
The Great Celestial Numbers - The Infinitely Big and The Infinitely Small
NASA Astrophysics Data System (ADS)
Teodorani, M.
2009-11-01
This book is a travel that brings the reader to penetrate dimensionally the infinitely small and the infinitely large in the Universe, ranging from quarks to galaxies, and to compare these extreme numbers with the numbers that people encounters in normal life here on Earth. Several numerical examples are illustrated all over the text in a sort of scientific orienteering that describes dimensionally the realms of space, time and energy. The last part of the book shows how all spatial and temporal dimensions disappear when the mechanism of quantum entanglement is considered.
Configuration interaction calculations with infinite angular = expansions
Goldman, S.P.; Glickman, T.
1996-05-01
The Modified Configuration Interaction (MCI) method improves the angular convergence of Configuration Interaction (CI) calculations by several orders of magnitude by mixing a priori a large number of angular basis functions. With MCI one can therefore use basis functions with very large angular momentum quantum numbers, overcoming an important limitation of conventional CI. Although this is desirable given the excellent convergence obtained, the large number of angular integrations and the calculation of n-j symbols with large values of l to high accuracy, make the angular calculations lengthy. In this work a new angular representation for CI calculations is presented that is much more efficient and powerful. Instead of the large number of angular functions of MCI the authors use a basis set containing an infinite linear combination of angular functions. All the necessary integrations involving these infinite expansions are done in closed form and are actually easy and fast to compute. The linear coefficients in the angular expansion are optimized in terms of a few non-linear parameters. Several examples will be presented with applications to two-electron systems.
Infinite densities for Lévy walks
NASA Astrophysics Data System (ADS)
Rebenshtok, A.; Denisov, S.; Hänggi, P.; Barkai, E.
2014-12-01
Motion of particles in many systems exhibits a mixture between periods of random diffusive-like events and ballistic-like motion. In many cases, such systems exhibit strong anomalous diffusion, where low-order moments <|x (t ) |q> with q below a critical value qc exhibit diffusive scaling while for q >qc a ballistic scaling emerges. The mixed dynamics constitutes a theoretical challenge since it does not fall into a unique category of motion, e.g., the known diffusion equations and central limit theorems fail to describe both aspects. In this paper we resolve this problem by resorting to the concept of infinite density. Using the widely applicable Lévy walk model, we find a general expression for the corresponding non-normalized density which is fully determined by the particles velocity distribution, the anomalous diffusion exponent α , and the diffusion coefficient Kα. We explain how infinite densities play a central role in the description of dynamics of a large class of physical processes and discuss how they can be evaluated from experimental or numerical data.
Screening and validation of EXTraS data products
NASA Astrophysics Data System (ADS)
Carpano, Stefania; Haberl, F.; De Luca, A.; Tiengo, A.: Israel, G.; Rodriguez, G.; Belfiore, A.; Rosen, S.; Read, A.; Wilms, J.; Kreikenbohm, A.; Law-Green, D.
2015-09-01
The EXTraS project (Exploring the X-ray Transient and variable Sky) is aimed at fullyexploring the serendipitous content of the XMM-Newton EPIC database in the timedomain. The project is funded within the EU/FP7-Cooperation Space framework and is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany). The several tasks consist in characterise aperiodicvariability for all 3XMM sources, search for short-term periodic variability on hundreds of thousands sources, detect new transient sources that are missed by standard source detection and hence not belonging to the 3XMM catalogue, search for long term variability by measuring fluxes or upper limits for both pointed and slew observations, and finally perform multiwavelength characterisation andclassification. Screening and validation of the different products is essentially in order to reject flawed results, generated by the automatic pipelines. We present here the screening tool we developed in the form of a Graphical User Interface and our plans for a systematic screening of the different catalogues.
STS-109 Extra Vehicular Activity (EVA)
NASA Technical Reports Server (NTRS)
2002-01-01
Inside the Space Shuttle Columbia's cabin, astronaut Nancy J. Currie, mission specialist, controlled the Remote Manipulator System (RMS) on the crew cabin's aft flight deck to assist fellow astronauts during the STS-109 mission Extra Vehicular Activities (EVA). The RMS was used to capture the telescope and secure it into Columbia's cargo bay. The Space Shuttle Columbia STS-109 mission lifted off March 1, 2002 with goals of repairing and upgrading the Hubble Space Telescope (HST). The Marshall Space Flight Center in Huntsville, Alabama had the responsibility for the design, development, and construction of the HST, which is the most powerful and sophisticated telescope ever built. STS-109 upgrades to the HST included: replacement of the solar array panels; replacement of the power control unit (PCU); replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. Lasting 10 days, 22 hours, and 11 minutes, the STS-109 mission was the 108th flight overall in NASA's Space Shuttle Program.
Statistical Mechanics of Infinite Gravitating Systems
NASA Astrophysics Data System (ADS)
Saslaw, William C.
2008-01-01
The cosmological many-body problem was stated over 300 years ago, but its solution is quite recent and still incomplete. Imagine an infinite expanding universe essentially containing a very large number of objects moving in response to their mutual gravitational forces. What will be the spatial and velocity distributions of these objects and how will they evolve? This question fascinates on many levels. Though inherently non-linear, it turns out to be one of the few analytically solvable problems of statistical mechanics with long range forces. The partition function can be calculated. From this all the thermodynamic properties of the system can be obtained for the grand canonical ensemble. They confirm results derived independently directly from the first and second laws of thermodynamics. The behavior of infinite gravitating systems is quite different from their finite relations such as star clusters. Infinite gravitating systems have regimes of negative specific heat, an unusual type of phase transition, and a very close relation to the observed large-scale structure of our universe. This last feature provides an additional astronomical motivation, especially since the statistical mechanics may be generalized to include effects of dark matter haloes around galaxies. Previously the cosmological many-body problem has mostly been studied using the BBGKY hierarchy (not so suitable in the non-linear regime) and by direct computer integrations of the objects' orbits. The statistical mechanics agrees with and substantially extends these earlier results. Most astrophysicists had previously thought that a statistical thermodynamic approach would not be applicable because: a) many-body gravitational systems have no rigorous equilibrium state, b) the unshielded nature of the long-range force would cause the partition function to diverge on large scales, and c) point masses would produce divergences on small scales. However, deeper considerations show that these are not
Simulating infinite vortex lattices in superfluids
NASA Astrophysics Data System (ADS)
Mingarelli, Luca; Keaveny, Eric E.; Barnett, Ryan
2016-07-01
We present an efficient framework to numerically treat infinite periodic vortex lattices in rotating superfluids described by the Gross–Pitaevskii theory. The commonly used split-step Fourier (SSF) spectral methods are inapplicable to such systems as the standard Fourier transform does not respect the boundary conditions mandated by the magnetic translation group. We present a generalisation of the SSF method which incorporates the correct boundary conditions by employing the so-called magnetic Fourier transform. We test the method and show that it reduces to known results in the lowest-Landau-level regime. While we focus on rotating scalar superfluids for simplicity, the framework can be naturally extended to treat multicomponent systems and systems under more general ‘synthetic’ gauge fields.
Nonlinear Shear Instabilities in an Infinite Slab
NASA Astrophysics Data System (ADS)
Nepveu, M.
1982-08-01
The dynamical evolution of an infinite slab moving in denser and noisy (turbulent) surroundings is investigated with a 2D hydrodynamic code. The applicability of the results to astrophysical jets is discussed. Inviscid beams show internal shocks at regular intervals of a few beamwidths. Kinks are not obvious. In viscous beams shocks are less outspoken, but turbulence is triggered with maximum scales of a few beamwidths. These viscous beams broaden. Linear stability analysis may hold up to a few e-folding times, although the seed disturbance field is not infinitesimal. The computations suggest that viscous astrophysical beams may become blurred quite suddenly and may give rise to sudden change in radiation patterns (NGC 1265).
Infinite Index Subfactors and the GICAR Categories
NASA Astrophysics Data System (ADS)
Jones, Vaughan F. R.; Penneys, David
2015-10-01
Given a II1-subfactor of arbitrary index, we show that the rectangular GICAR category, also called the rectangular planar rook category, faithfully embeds as A - A bimodule maps among the bimodules . As a corollary, we get a lower bound on the dimension of the centralizer algebras for infinite index subfactors, and we also get that is nonabelian for , where is the Jones tower for . We also show that the annular GICAR/planar rook category acts as maps amongst the A-central vectors in , although this action may be degenerate. We prove these results in more generality using bimodules. The embedding of the GICAR category builds on work of Connes and Evans, who originally found GICAR algebras inside Temperley-Lieb algebras with finite modulus.
Simulating infinite vortex lattices in superfluids.
Mingarelli, Luca; Keaveny, Eric E; Barnett, Ryan
2016-07-20
We present an efficient framework to numerically treat infinite periodic vortex lattices in rotating superfluids described by the Gross-Pitaevskii theory. The commonly used split-step Fourier (SSF) spectral methods are inapplicable to such systems as the standard Fourier transform does not respect the boundary conditions mandated by the magnetic translation group. We present a generalisation of the SSF method which incorporates the correct boundary conditions by employing the so-called magnetic Fourier transform. We test the method and show that it reduces to known results in the lowest-Landau-level regime. While we focus on rotating scalar superfluids for simplicity, the framework can be naturally extended to treat multicomponent systems and systems under more general 'synthetic' gauge fields. PMID:27219843
Algebraic independence properties related to certain infinite products
NASA Astrophysics Data System (ADS)
Tanaka, Taka-aki
2011-09-01
In this paper we establish algebraic independence of the values of a certain infinite product as well as its all successive derivatives at algebraic points other than its zeroes, using the fact that the logarithmic derivative of an infinite product gives a partial fraction expansion. Such an infinite product is generated by a linear recurrence. The method used for proving the algebraic independence is based on the theory of Mahler functions of several variables.
Pang, Yu; Liu, Yu-Shan; Liu, Jin-Xi; Feng, Wen-Jie
2016-04-01
In this paper, SH bulk/surface waves propagating in the corresponding infinite/semi-infinite piezoelectric (PE)/piezomagnetic (PM) and PM/PE periodically layered composites are investigated by two methods, the stiffness matrix method and the transfer matrix method. For a semi-infinite PE/PM or PM/PE medium, the free surface is parallel to the layer interface. Both PE and PM materials are assumed to be transversely isotropic solids. Dispersion equations are derived by the stiffness/transfer matrix methods, respectively. The effects of electric-magnetic (ME) boundary conditions at the free surface and the layer thickness ratios on dispersion curves are considered in detail. Numerical examples show that the results calculated by the two methods are the same. The dispersion curves of SH surface waves are below the bulk bands or inside the frequency gaps. The ratio of the layer thickness has an important effect not only on the bulk bands but also on the dispersion curves of SH surface waves. Electric and magnetic boundary conditions, respectively, determine the dispersion curves of SH surface waves for the PE/PM and PM/PE semi-infinite structures. The band structures of SH bulk waves are consistent for the PE/PM and PM/PE structures, however, the dispersive behaviors of SH surface waves are indeed different for the two composites. The realization of the above-mentioned characteristics of SH waves will make it possible to design PE/PM acoustic wave devices with periodical structures and achieve the better performance. PMID:26836289
Infinite-range exterior complex scaling as a perfect absorber in time-dependent problems
Scrinzi, Armin
2010-05-15
We introduce infinite range exterior complex scaling (irECS) which provides for complete absorption of outgoing flux in numerical solutions of the time-dependent Schroedinger equation with strong infrared fields. This is demonstrated by computing high harmonic spectra and wave-function overlaps with the exact solution for a one-dimensional model system and by three-dimensional calculations for the H atom and an Ne atom model. We lay out the key ingredients for correct implementation and identify criteria for efficient discretization.
Dimensional regularization of the path integral in curved space on an infinite time interval
NASA Astrophysics Data System (ADS)
Bastianelli, F.; Corradini, O.; van Nieuwenhuizen, P.
2000-09-01
We use dimensional regularization to evaluate quantum mechanical path integrals in arbitrary curved spaces on an infinite time interval. We perform 3-loop calculations in Riemann normal coordinates, and 2-loop calculations in general coordinates. It is shown that one only needs a covariant two-loop counterterm (VDR=ℏ2/8R) to obtain the same results as obtained earlier in other regularization schemes. It is also shown that the mass term needed in order to avoid infrared divergences explicitly breaks general covariance in the final result.
Extra Chance Generalized Hybrid Monte Carlo
NASA Astrophysics Data System (ADS)
Campos, Cédric M.; Sanz-Serna, J. M.
2015-01-01
We study a method, Extra Chance Generalized Hybrid Monte Carlo, to avoid rejections in the Hybrid Monte Carlo method and related algorithms. In the spirit of delayed rejection, whenever a rejection would occur, extra work is done to find a fresh proposal that, hopefully, may be accepted. We present experiments that clearly indicate that the additional work per sample carried out in the extra chance approach clearly pays in terms of the quality of the samples generated.
Origin of a peculiar extra U(1)
Barr, S.M.; Dorsner, I.
2005-07-01
The origin of a family-independent ''extra U(1)'', discovered by Barr, Bednarz, and Benesh and independently by Ma, and whose phenomenology has recently been studied by Ma and Roy, is discussed. Even though it satisfies anomaly constraints in a highly economical way, with just a single extra triplet of leptons per family, this extra U(1) cannot come from four-dimensional grand unification. However, it is shown here that it can come from a Pati-Salam scheme with an extra U(1), which explains the otherwise surprising cancellation of anomalies.
Solenoid magnetic fields calculated from superposed semi-infinite solenoids
NASA Technical Reports Server (NTRS)
Brown, G. V.; Flax, L.
1966-01-01
Calculation of a thick solenoid coils magnetic field components is made by a superposition of the fields produced by four solenoids of infinite length and zero inner radius. The field produced by this semi-infinite solenoid is dependent on only two variables, the radial and axial field point coordinates.
A New Look at Infinitives in Business and Technical Writing.
ERIC Educational Resources Information Center
Myers, Marshall
2002-01-01
Argues the infinitive phrase has not been taken seriously in writing because writers have been too concerned with Bishop Robert Lowth's proscription against the split infinitive. Notes that examination of three types of technical prose (instructions, annual reports, and "junk mail") reveals that more than one sentence in four contains an…
Use of Physical Analogs to Evaluate Infinite Series.
ERIC Educational Resources Information Center
Epstein, D. J.; Smith, A. C.
1979-01-01
Discusses the paradoxes that can result when physical examples lead to infinite series. Two examples are presented: the Madelung energy of a one-dimensional array of alternating positive and negative charges, and a point charge between infinite parallel plates. (BB)
Infinite statistics condensate as a model of dark matter
Ebadi, Zahra; Mirza, Behrouz; Mohammadzadeh, Hosein E-mail: b.mirza@cc.iut.ac.ir
2013-11-01
In some models, dark matter is considered as a condensate bosonic system. In this paper, we prove that condensation is also possible for particles that obey infinite statistics and derive the critical condensation temperature. We argue that a condensed state of a gas of very weakly interacting particles obeying infinite statistics could be considered as a consistent model of dark matter.
The Infinite Challenge: Levels of Conceiving the Endlessness of Numbers
ERIC Educational Resources Information Center
Falk, Ruma
2010-01-01
To conceive the infinity of integers, one has to realize: (a) the unending possibility of increasing/decreasing numbers (potential infinity), (b) that the cardinality of the set of numbers is greater than that of any finite set (actual infinity), and (c) that the leap from a finite to an infinite set is itself infinite (immeasurable gap). Three…
Countable Infinite Sets and Inflationary Models
NASA Astrophysics Data System (ADS)
Berezin, Alexander A.
2000-04-01
Unreasonable effectiveness of mathematics (E.Wigner) recasts pythagorean "all things are made of numbers". Hypotheses of eternal inflation (A.Linde) and/or quantum branching (H.Everett) buttressed by platonic pressure principle (PPP) resonates with "for deriving all from nothing there suffices a single principle" (G.W.Leibnitz). Externalization of PPP uses patterns of factorizations of super-long integers (tower exponents, TE). PPP-TE explosive emergence of space-time-matter-energy rests on infinite complexity of factorizational and iterational patterns of integers. Thus, PPP is direct translation of metaphysical principle to physics of material world ("metaphysics works"). Countability of quantum states of bounded systems allows "listing" of all states of all baby universes through Godel-like counting with TE of primes. At each breeding step upper (Nth) prime of TE stack p1...pN counts (by multidimensional Cantor diagonal scheme) all universes AND all states in them. Exclusive use of primes in TEs assures non-overlapping counting. Cantor counting with non-crossing subsets of primes (and actual PPP emergence) can proceed both in "forward" and "backward" direction in megauniversal ("Newtonian") time. format.
Hearing and Infinite-Period Bifurcations
NASA Astrophysics Data System (ADS)
Ji, Seung; Bozovic, Dolores; Bruinsma, Robijn
2011-03-01
Auditory and vestibular systems present us with biological sensors that can achieve sub-nanometer sensitivity orders of magnitude in the dynamic range, while operating in a fluid-immersed, room-temperature environment. While the mechanisms behind this extreme sensitivity and robustness of the inner ear have not been fully explained, nonlinear response has been shown to be crucial to its proper function. Recent experiments have recorded innate motility of hair cells of the bullfrog sacculus, under varying degrees of steady-state offset. The bundle deflection was shown to suppress or enhance spontaneous oscillations, and affect the sensitivity of the mechanical response. We will present a theoretical model based on cubic nonlinearity and show that in different parameter regimes, the system can be induced to cross a supercritical Hopf bifurcation, an infinite-period bifurcation, or a multi-critical point. Comparing the numerical simulation to the experiment, we will present evidence that the multi-critical point corresponds most closely to the dynamic state of saccular hair cells. Further, we will discuss the crossing of the bifurcation, and the sensitivity of the phase-locked response in various frequency regimes.
Control system for an infinitely variable transmission
Sakai, Y.
1986-12-09
This patent describes a control system for an infinitely variable belt-drive transmission having a selector device including a drive range position and a neutral position, a drive pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc, and a driven pulley having a hydraulically shiftable disc and a servo chamber for shifting the disc. It also has a belt engaged with both the pulleys, a hydraulic control circuit for supplying oil to the servo chambers and for draining the servo chambers. The hydraulic control circuit is provided with a pressure regulator valve for providing a line pressure and a transmission ratio control valve for applying the line pressure to the servo chamber of the drive pulley. The improvement described here comprises: a lubricating oil circuit provided in the hydraulic control circuit for supplying lubricating oil to the drive and driven pulleys; a passage for supplying a part of the lubricating oil to the servo chamber of the drive pulley; a check valve provided in the passage for preventing the reverse flow of the lubricating oil; and a select position detecting valve for enabling the supply of the lubricating oil to the servo chamber at the selection of the neutral position.
Control system for an infinitely variable transmission
Morimoto, Y.
1987-07-21
A system is described for controlling an infinitely variable transmission for transmitting the power of an internal combustion engine through a clutch for driving a motor vehicle. The transmission comprises a drive pulley having a hydraulically shiftable disc and a hydraulic cylinder for shifting the disc, a driven pulley having a hydraulically shiftable disc and a hydraulic cylinder for operating the disc of the driven pulley, and a belt engaged with both pulleys. The system includes a pressure oil circuit having a pump for supplying pressurized oil, and a transmission ratio control valve having a spool for controlling the pressurized oil so as to move the disc of the drive pulley to change the actual transmission ratio of the transmission. The improvement in the system comprises: first means for moving the spool of the transmission ratio control valve; second means responsive to disengagement of the clutch, when speed of the vehicle is below a predetermined speed, for producing a coasting signal; third means responsive to the coasting signal for producing a drive pulley speed set signal; fourth means responsive to the drive pulley speed set signal for producing a shifting signal representing a quantity of shifting the spool of the transmission ratio control valve in upshifting direction, and fifth means responsive to the shifting signal for shifting the spool of the transmission ratio control valve in the upshifting direction via the first means thereby decreasing the drive pulley speed.
Physics of Extra Dimensions Final Report
Csaba Csaki
2007-12-19
We provide the final report for Csaba Csaki's OJI project on "Physics of extra dimensions". It includes the summary of results of higgsless electroweak symmetry breaking, gauge-higgs unification, AdS/QCD and holographic technicolor, and chiral lattice theories from warped extra dimensions.
Motion of a mirror under infinitely fluctuating quantum vacuum stress
NASA Astrophysics Data System (ADS)
Wang, Qingdi; Unruh, William G.
2014-04-01
The actual value of the quantum vacuum energy density is generally regarded as irrelevant in nongravitational physics. However, this paper presents a nongravitational system where this value does have physical significance. The system is a mirror with an internal degree of freedom that interacts with a scalar field. We find that the force exerted on the mirror by the field vacuum undergoes wild fluctuations with a magnitude proportional to the value of the vacuum energy density, which is mathematically infinite. This infinite fluctuating force gives infinite instantaneous acceleration of the mirror. We show that this infinite fluctuating force and infinite instantaneous acceleration make sense because they will not result in infinite fluctuation of the mirror's position. On the contrary, the mirror's fluctuating motion will be confined in a small region due to two special properties of the quantum vacuum: (1) the vacuum friction that resists the mirror's motion and (2) the strong anticorrelation of vacuum fluctuations that constantly changes the direction of the mirror's infinite instantaneous acceleration and thus cancels the effect of infinities to make the fluctuation of the mirror's position finite.
On the Atkinson-Johnson Homogeneous Solution for Infinite Systems
NASA Astrophysics Data System (ADS)
Laraudogoitia, Jon Pérez
2015-05-01
This paper shows that the general homogeneous solution to equations of evolution for some infinite systems of particles subject to mutual binary collisions does not depend on a single arbitrary constant but on a potentially infinite number of such constants. This is because, as I demonstrate, a single self-excitation of a system of particles can depend on a potentially infinite number of parameters. The recent homogeneous solution obtained by Atkinson and Johnson, which depends on a single arbitrary constant, is only a particular case.
Inequality for the infinite-cluster density in Bernoulli percolation
Chayes, J.T.; Chayes, L.
1986-04-21
Under a certain assumption (which is satisfied whenever there is a dense infinite cluster in the half-space), we prove a differential inequality for the infinite-cluster density, P/sub infinity/(p), in Bernoulli percolation. The principal implication of this result is that if P/sub infinity/(p) vanishes with critical exponent ..beta.., then ..beta.. obeys the mean-field bound ..beta..< or =1. As a corollary, we also derive an inequality relating the backbone density, the truncated susceptibility, and the infinite-cluster density.
Tight Lower Bound for Percolation Threshold on an Infinite Graph
NASA Astrophysics Data System (ADS)
Hamilton, Kathleen E.; Pryadko, Leonid P.
2014-11-01
We construct a tight lower bound for the site percolation threshold on an infinite graph, which becomes exact for an infinite tree. The bound is given by the inverse of the maximal eigenvalue of the Hashimoto matrix used to count nonbacktracking walks on the original graph. Our bound always exceeds the inverse spectral radius of the graph's adjacency matrix, and it is also generally tighter than the existing bound in terms of the maximum degree. We give a constructive proof for existence of such an eigenvalue in the case of a connected infinite quasitransitive graph, a graph-theoretic analog of a translationally invariant system.
Parabosons, parafermions, and explicit representations of infinite-dimensional algebras
Stoilova, N. I.; Van der Jeugt, J.
2010-03-15
The goal of this paper is to give an explicit construction of the Fock spaces of the parafermion and the paraboson algebra, for an infinite set of generators. This is equivalent to constructing certain unitary irreducible lowest weight representations of the (infinite rank) Lie algebra so({infinity}) and of the Lie superalgebra osp(1 vertical bar {infinity}). A complete solution to the problem is presented, in which the Fock spaces have basis vectors labeled by certain infinite but stable Gelfand-Zetlin patterns, and the transformation of the basis is given explicitly. Alternatively, the basis vectors can be expressed as semi-standard Young tableaux.
ERIC Educational Resources Information Center
Lascours, Jean; Albe, Virginie
2001-01-01
Describes a series of simple and nontraditional experiments that enable students to discover the properties of infrared radiation by studying the propagation, reflection, diffusion, and refraction of infrared. The experiments rely on two modules, an infrared transmitter and an infrared receiver. (SAH)
Extra-articular Manifestations in Rheumatoid Arthritis
Cojocaru, Manole; Cojocaru, Inimioara Mihaela; Silosi, Isabela; Vrabie, Camelia Doina; Tanasescu, R
2010-01-01
ABSTRACT Rheumatoid arthritis (RA) is a systemic autoimmune disease whose main characteristic is persistent joint inflammation that results in joint damage and loss of function. Although RA is more common in females, extra-articular manifestations of the disease are more common in males. The extra-articular manifestations of RA can occur at any age after onset. It is characterised by destructive polyarthritis and extra-articular organ involvement, including the skin, eye, heart, lung, renal, nervous and gastrointestinal systems. The frequence of extra-articular manifestations in RA differs from one country to another. Extra-articular organ involvement in RA is more frequently seen in patients with severe, active disease and is associated with increased mortality. Incidence and frequence figures for extra-articular RA vary according to study design. Extra-articular involvement is more likely in those who have RF and/or are HLA-DR4 positive. Occasionally, there are also systemic manifestations such as vasculitis, visceral nodules, Sjögren's syndrome, or pulmonary fibrosis present. Nodules are the most common extra-articular feature, and are present in up to 30%; many of the other classic features occur in 1% or less in normal clinic settings. Sjögren's syndrome, anaemia of chronic disease and pulmonary manifestations are relatively common – in 6-10%, are frequently present in early disease and are all related to worse outcomes measures of rheumatoid disease in particular functional impairment and mortality. The occurrence of these systemic manifestations is a major predictor of mortality in patients with RA. This paper focuses on extra-articular manifestations, defined as diseases and symptoms not directly related to the locomotor system. PMID:21977172
Gacs quantum algorithmic entropy in infinite dimensional Hilbert spaces
Benatti, Fabio; Oskouei, Samad Khabbazi Deh Abad, Ahmad Shafiei
2014-08-15
We extend the notion of Gacs quantum algorithmic entropy, originally formulated for finitely many qubits, to infinite dimensional quantum spin chains and investigate the relation of this extension with two quantum dynamical entropies that have been proposed in recent years.
Searching for extra-dimensions at CMS
NASA Astrophysics Data System (ADS)
Benucci, Leonardo
2009-06-01
A possible solution to the hierarchy problem is the presence of extra space dimensions beyond the three ones which are known from our everyday experience. The phenomenological ADD model of large extra-dimensions predicts a ETmiss +jet signature. Randall-Sundrum-type extra-dimensions predict di-lepton and di-jet resonances. This contribution addresses an overview of experimental issues and discovery potential for these new particles at the LHC, focusing on perspectives with the CMS detector during early data taking.
A notion of graph likelihood and an infinite monkey theorem
NASA Astrophysics Data System (ADS)
Banerji, Christopher R. S.; Mansour, Toufik; Severini, Simone
2014-01-01
We play with a graph-theoretic analogue of the folklore infinite monkey theorem. We define a notion of graph likelihood as the probability that a given graph is constructed by a monkey in a number of time steps equal to the number of vertices. We present an algorithm to compute this graph invariant and closed formulas for some infinite classes. We have to leave the computational complexity of the likelihood as an open problem.
Optimal feedback control infinite dimensional parabolic evolution systems: Approximation techniques
NASA Technical Reports Server (NTRS)
Banks, H. T.; Wang, C.
1989-01-01
A general approximation framework is discussed for computation of optimal feedback controls in linear quadratic regular problems for nonautonomous parabolic distributed parameter systems. This is done in the context of a theoretical framework using general evolution systems in infinite dimensional Hilbert spaces. Conditions are discussed for preservation under approximation of stabilizability and detectability hypotheses on the infinite dimensional system. The special case of periodic systems is also treated.
A unified approach to infinite-dimensional integration
NASA Astrophysics Data System (ADS)
Albeverio, S.; Mazzucchi, S.
2016-04-01
An approach to infinite-dimensional integration which unifies the case of oscillatory integrals and the case of probabilistic type integrals is presented. It provides a truly infinite-dimensional construction of integrals as linear functionals, as much as possible independent of the underlying topological and measure theoretical structure. Various applications are given, including, next to Feynman path integrals, Schrödinger and diffusion equations, as well as higher order hyperbolic and parabolic equations.
Editorial: Focus on Extra Space Dimensions
NASA Astrophysics Data System (ADS)
Agashe, Kaustubh; Pomarol, Alex
2010-07-01
Experiments at the Large Hadron Collider (LHC) have just started. In addition to verifying the Standard Model (SM) of particle physics, these experiments will probe a new energy frontier and test extensions of the SM. The existence of extra dimensions is one of the most attractive possibilities for physics beyond the SM. This focus issue contains a collection of articles addressing both theoretical and phenomenological aspects of extra-dimensional models. Focus on Extra Space Dimensions Contents Minimal universal extra dimensions in CalcHEP/CompHEP AseshKrishna Datta, Kyoungchul Kong and Konstantin T Matchev Disordered extra dimensions Karim Benakli Codimension-2 brane-bulk matching: examples from six and ten dimensions Allan Bayntun, C P Burgess and Leo van Nierop Gauge threshold corrections in warped geometry Kiwoon Choi, Ian-Woo Kim and Chang Sub Shin Holographic methods and gauge-Higgs unification in flat extra dimensions Marco Serone Soft-wall stabilization Joan A Cabrer, Gero von Gersdorff and Mariano Quirós Warped five-dimensional models: phenomenological status and experimental prospects Hooman Davoudiasl, Shrihari Gopalakrishna, Eduardo Pontón and José Santiago
Measures of correlations in infinite-dimensional quantum systems
NASA Astrophysics Data System (ADS)
Shirokov, M. E.
2016-05-01
Several important measures of correlations of the state of a finite-dimensional composite quantum system are defined as linear combinations of marginal entropies of this state. This paper is devoted to infinite-dimensional generalizations of such quantities and to an analysis of their properties. We introduce the notion of faithful extension of a linear combination of marginal entropies and consider several concrete examples, the simplest of which are quantum mutual information and quantum conditional entropy. Then we show that quantum conditional mutual information can be defined uniquely as a lower semicontinuous function on the set of all states of a tripartite infinite-dimensional system possessing all the basic properties valid in finite dimensions. Infinite-dimensional generalizations of some other measures of correlations in multipartite quantum systems are also considered. Applications of the results to the theory of infinite-dimensional quantum channels and their capacities are considered. The existence of a Fawzi-Renner recovery channel reproducing marginal states for all tripartite states (including states with infinite marginal entropies) is shown. Bibliography: 47 titles.
On the problem of quantum control in infinite dimensions
NASA Astrophysics Data System (ADS)
Vilela Mendes, R.; Man'ko, Vladimir I.
2011-04-01
In the framework of bilinear control of the Schrödinger equation, it has been proved that the reachable set has a dense complement in {S} \\cap {H}^{2}. Hence, in this setting, exact quantum control in infinite dimensions is not possible. On the other hand, it is known that there is a simple choice of operators which, when applied to an arbitrary state, generate dense orbits in Hilbert space. Compatibility of these two results is established in this paper and, in particular, it is proved that the closure of the reachable set of bilinear control is dense in {S} \\cap {H}^{2}. The requirements for controllability in infinite dimensions are also related to the properties of the infinite-dimensional unitary group.
Roberts, C.C. Jr.
1982-12-01
Infrared thermography is a useful tool for the diagnosis of problems in building systems. In instances where a building owner has several large buildings, an investment in a typical $30,000 infrared system may be cost effective. In most instances, however, the rental of an infrared system or the hiring of an infrared consulting service is a cost effective alternative. As can be seen from the several applications presented here, any mechanical problem manifesting itself in an atypical temperature pattern can usually be detected. The two primary savings generated from infrared analysis of building systems are maintenance and energy.
Dynamics with infinitely many derivatives: the initial value problem
NASA Astrophysics Data System (ADS)
Barnaby, Neil; Kamran, Niky
2008-02-01
Differential equations of infinite order are an increasingly important class of equations in theoretical physics. Such equations are ubiquitous in string field theory and have recently attracted considerable interest also from cosmologists. Though these equations have been studied in the classical mathematical literature, it appears that the physics community is largely unaware of the relevant formalism. Of particular importance is the fate of the initial value problem. Under what circumstances do infinite order differential equations possess a well-defined initial value problem and how many initial data are required? In this paper we study the initial value problem for infinite order differential equations in the mathematical framework of the formal operator calculus, with analytic initial data. This formalism allows us to handle simultaneously a wide array of different nonlocal equations within a single framework and also admits a transparent physical interpretation. We show that differential equations of infinite order do not generically admit infinitely many initial data. Rather, each pole of the propagator contributes two initial data to the final solution. Though it is possible to find differential equations of infinite order which admit well-defined initial value problem with only two initial data, neither the dynamical equations of p-adic string theory nor string field theory seem to belong to this class. However, both theories can be rendered ghost-free by suitable definition of the action of the formal pseudo-differential operator. This prescription restricts the theory to frequencies within some contour in the complex plane and hence may be thought of as a sort of ultra-violet cut-off. Our results place certain recent attempts to study inflation in the context of nonlocal field theories on a much firmer mathematical footing.
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.
Infinite tension limit of the pure spinor superstring
NASA Astrophysics Data System (ADS)
Berkovits, Nathan
2014-03-01
Mason and Skinner recently constructed a chiral infinite tension limit of the Ramond-Neveu-Schwarz superstring which was shown to compute the Cachazo-He-Yuan formulae for tree-level d = 10 Yang-Mills amplitudes and the NS-NS sector of tree-level d = 10 supergravity amplitudes. In this letter, their chiral infinite tension limit is generalized to the pure spinor superstring which computes a d = 10 superspace version of the Cachazo-He-Yuan formulae for tree-level d = 10 super-Yang-Mills and supergravity amplitudes.
Robust Consumption-Investment Problem on Infinite Horizon
Zawisza, Dariusz
2015-12-15
In our paper we consider an infinite horizon consumption-investment problem under a model misspecification in a general stochastic factor model. We formulate the problem as a stochastic game and finally characterize the saddle point and the value function of that game using an ODE of semilinear type, for which we provide a proof of an existence and uniqueness theorem for its solution. Such equation is interested on its own right, since it generalizes many other equations arising in various infinite horizon optimization problems.
Gravitational waves from kinks on infinite cosmic strings
Kawasaki, Masahiro; Miyamoto, Koichi; Nakayama, Kazunori
2010-05-15
Gravitational waves emitted by kinks on infinite strings are investigated using detailed estimations of the kink distribution on infinite strings. We find that gravitational waves from kinks can be detected by future pulsar timing experiments such as SKA for an appropriate value of the string tension, if the typical size of string loops is much smaller than the horizon at their formation. Moreover, the gravitational wave spectrum depends on the thermal history of the Universe and hence it can be used as a probe into the early evolution of the Universe.
Extra-dimensional models on the lattice
Knechtli, Francesco; Rinaldi, Enrico
2016-08-05
In this paper we summarize the ongoing effort to study extra-dimensional gauge theories with lattice simulations. In these models the Higgs field is identified with extra-dimensional components of the gauge field. The Higgs potential is generated by quantum corrections and is protected from divergences by the higher dimensional gauge symmetry. Dimensional reduction to four dimensions can occur through compactification or localization. Gauge-Higgs unification models are often studied using perturbation theory. Numerical lattice simulations are used to go beyond these perturbative expectations and to include nonperturbative effects. We describe the known perturbative predictions and their fate in the strongly-coupled regime formore » various extra-dimensional models.« less
Extra and Intra-articular Synovial Chondromatosis.
Chaudhary, R K; Banskota, B; Rijal, S; Banskota, A K
2015-01-01
Synovial chondromatosis is not so rare intra-articular condition secondary to synovial metaplasia, that affects the knee joint. Extra-articular synovial chondromatosis however is an extremely rare condition that usually involves the synovial sheath or bursa of the foot or hand. We present two cases of synovial chondromatosis, one intra and one extra-articular. The first case was a 25 year old lady who presented with pain, swelling and restricted range of motion of left knee and was found to have an intra-articular synovial chondromatosis which was treated successfully by joint debridement. The second case was that of a 22 year old man who presented with right knee pain and was diagnosed to have an extra-articular synovial chondromatosis of his right medial hamstring tendon sheath, excision of which resulted in complete relief of symptoms. PMID:27549506
Technology Transfer Automated Retrieval System (TEKTRAN)
Recent studies on the use of near infrared (NIR) spectroscopy for the qualitative characterization of extra virgin olive oil, are reported and discussed in this paper. Research results confirms that NIR spectroscopy, combined with chemometric data analysis, allows to simultaneously evaluate all qual...
Plettner, T.; Byer, R.L.; Colby, E.; Cowan, B.; Sears, C.M.S.; Spencer, J.E.; Siemann, R.H.; /SLAC
2006-03-01
We recently achieved the first experimental observation of laser-driven particle acceleration of relativistic electrons from a single Gaussian near-infrared laser beam in a semi-infinite vacuum. This article presents an in-depth account of key aspects of the experiment. An analysis of the transverse and longitudinal forces acting on the electron beam is included. A comparison of the observed data to the acceleration viewed as an inverse transition radiation process is presented. This is followed by a detailed description of the components of the experiment and a discussion of future measurements.
Explaining the Distribution of Infinitives of Impersonals in Russian
ERIC Educational Resources Information Center
Fortuin, Egbert
2011-01-01
In Russian infinitives of impersonal verbs have a peculiar distribution: they are not acceptable in most syntactic contexts, but there are also syntactic contexts in which they are perfectly acceptable. Based on a qualitative analysis of data from corpora, the Internet and an acceptability survey, it is argued that the restrictions on impersonals…
On the steady propagation of a semi-infinite crack
Paukshto, M.V.; Sulimov, M.G.
1994-12-25
We consider the rectilinear propagation of a semi-infinite crack with constant velocity in a crystal structure. We obtain the solutions of homogeneous boundary-value problems for the corresponding difference-differential operators in spaces of one and two dimensions. We give a justification of the computational aspect of the problem.
Stability analysis of a stochastic logistic model with infinite delay
NASA Astrophysics Data System (ADS)
Liu, Meng; Fan, Dejun; Wang, Ke
2013-09-01
This report is concerned with a stochastic logistic equation with infinite delay. We establish the sufficient conditions for global asymptotical stability of the zero solution and the positive equilibrium. Some classical results are improved and extended. Several numerical simulations are introduced to illustrate the main results.
Activity coefficients of chlorophenols in water at infinite dilution
Tabai, S.; Rogalski, M.; Solimando, R.; Malanowski, S.K.
1997-11-01
The total pressure of aqueous solutions of chlorophenols was determined by a ebulliometric total pressure method for the aqueous solutions of phenol, 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, and 2,4-dichlorophenol in the temperature range from 40 to 90 C. The activity coefficients at infinite dilution and the Henry constants were derived.
Reparametrization of the Relativistic Infinitely Extended Charged Particle Action
NASA Astrophysics Data System (ADS)
Saadat, Hassan; Pourhassan, Behnam
2016-09-01
In this letter, relativistic infinitely extended particles formulated. Correct form of action with possibility of reparametrization obtained and effect of electric field considered. It may be one of the first step to re-introduce theory of every things given by Nakano and Hessaby many years ago.
Young Students Exploring Cardinality by Constructing Infinite Processes
ERIC Educational Resources Information Center
Kahn, Ken; Sendova, Evgenia; Sacristan, Ana Isabel; Noss, Richard
2011-01-01
In this paper, we describe the design and implementation of computer programming activities aimed at introducing young students (9-13 years old) to the idea of infinity, and in particular, to the cardinality of infinite sets. This research was part of the "WebLabs" project where students from several European countries explored topics in…
Functional DNA: Teaching Infinite Series through Genetic Analogy
ERIC Educational Resources Information Center
Kowalski, R. Travis
2011-01-01
This article presents an extended analogy that connects infinite sequences and series to the science of genetics, by identifying power series as "DNA for a function." This analogy allows standard topics such as convergence tests or Taylor approximations to be recast in a "forensic" light as mathematical analogs of genetic concepts such as DNA…
On the sound fields of infinitely long strips.
Mellow, Tim; Kärkkäinen, Leo
2011-07-01
Exact solutions are derived for sound radiation from four kinds of infinitely-long strips: namely a rigid strip in a baffle of finite width, a resilient strip in free space, and a resilient or rigid strip in an infinite baffle. In one limit, the strip in a finite baffle becomes a rigid strip in free space and in the other, a line source in a finite baffle. Here "rigid" means that the surface velocity is uniform, whereas "resilient" means that the surface pressure is uniform, and the strip is assumed to have zero mass or stiffness, as if a force were driving the acoustic medium directly. According to the Babinet-Bouwkamp principle, radiation from a resilient strip in an infinite baffle is equivalent to diffraction of a plane wave through a slit in the same. Plots are shown for the radiation impedances, far-field directivity patterns, and on-axis pressure responses of the four kinds of strip. A simple relationship between the radiation admittance of the rigid strip in an infinite baffle and the resilient strip in free space is presented. The two-dimensional rectangular wave functions developed in this paper can be applied to related problems. PMID:21786886
The Limits of Some Infinite Families of Complex Contracting Mappings
Pagon, Dusan
2008-11-13
Self-similarity is strongly presented in modern mathematics and physics. We study a broad class of planar fractals--strongly self-similar sets of points in complex plane, obtained from a unit interval as geometric limits of certain infinite families of contracting mappings. Different 1-1 correspondences between the constructed set and the initial unit interval are established.
The physics of FEL in an infinite electron beam
Wang, G.; Litvinenko, V.N.; Webb, S.
2010-10-07
We solve linearized Vlasov-Maxwell FEL equations for a 3-D perturbation in the infinite electron beam with Lorentzian energy distributions using paraxial approximation. We present analytical solutions for various initial perturbations and discuss the effect of optical guiding in such system.
The infinite interface limit of multiple-region relaxed magnetohydrodynamics
Dennis, G. R.; Dewar, R. L.; Hole, M. J.; Hudson, S. R.
2013-03-15
We show the stepped-pressure equilibria that are obtained from a generalization of Taylor relaxation known as multi-region, relaxed magnetohydrodynamics (MRXMHD) are also generalizations of ideal magnetohydrodynamics (ideal MHD). We show this by proving that as the number of plasma regions becomes infinite, MRXMHD reduces to ideal MHD. Numerical convergence studies illustrating this limit are presented.
Plasmonic waves of a semi-infinite random nanocomposite
Moradi, Afshin
2013-10-15
The dispersion curves of the plasmonic waves of a semi-infinite random metal-dielectric nanocomposite, consisting of bulk metal embedded with dielectric inclusions, are presented. Two branches of p-polarized surface plasmon-polariton modes are found to exist. The possibility of experimentally observing the surface waves by attenuated total reflection is demonstrated.
Finding sums for an infinite class of alternating series
NASA Astrophysics Data System (ADS)
Chen, Zhibo; Wei, Sheng; Xiao, Xuerong
2012-07-01
Calculus II students know that many alternating series are convergent by the Alternating Series Test. However, they know few alternating series (except geometric series and some trivial ones) for which they can find the sum. In this article, we present a method that enables the students to find sums for infinitely many alternating series in the following form ?
Finding Sums for an Infinite Class of Alternating Series
ERIC Educational Resources Information Center
Chen, Zhibo; Wei, Sheng; Xiao, Xuerong
2012-01-01
Calculus II students know that many alternating series are convergent by the Alternating Series Test. However, they know few alternating series (except geometric series and some trivial ones) for which they can find the sum. In this article, we present a method that enables the students to find sums for infinitely many alternating series in the…
Infinite and Finite Games: Play and Visual Culture
ERIC Educational Resources Information Center
Hicks, Laurie E.
2004-01-01
In this article, I shall argue for the value of conceptualizing, and practicing art education as a kind of play or game, drawing inspiration from the concepts of finite and infinite games articulated by philosopher James Carse (1986). In so doing, I seek to encourage a continuing dialogue with the assumptions that constrain the theoretical basis…
Progress in extra-solar planet detection
NASA Technical Reports Server (NTRS)
Brown, Robert A.
1991-01-01
Progress in extra-solar planet detection is reviewed. The following subject areas are covered: (1) the definition of a planet; (2) the weakness of planet signals; (3) direct techniques - imaging and spectral detection; and (4) indirect techniques - reflex motion and occultations.
Extra virgin olive oil's polyphenols: biological activities.
Visioli, Francesco; Bernardini, Elena
2011-01-01
In addition to its high proportion of oleic acid (which is considered as "neutral" in terms of cardioprotection), extra virgin olive oil is rich in phenolic compounds, which other vegetable oils do not contain. This review critically appraises the current scientific evidence of a healthful role of olive phenols, with particular emphasis on hydroxytyrosol and related molecules. PMID:21443485
One-dimensional gravity in infinite point distributions.
Gabrielli, A; Joyce, M; Sicard, F
2009-10-01
The dynamics of infinite asymptotically uniform distributions of purely self-gravitating particles in one spatial dimension provides a simple and interesting toy model for the analogous three dimensional problem treated in cosmology. In this paper we focus on a limitation of such models as they have been treated so far in the literature: the force, as it has been specified, is well defined in infinite point distributions only if there is a centre of symmetry (i.e., the definition requires explicitly the breaking of statistical translational invariance). The problem arises because naive background subtraction (due to expansion, or by "Jeans swindle" for the static case), applied as in three dimensions, leaves an unregulated contribution to the force due to surface mass fluctuations. Following a discussion by Kiessling of the Jeans swindle in three dimensions, we show that the problem may be resolved by defining the force in infinite point distributions as the limit of an exponentially screened pair interaction. We show explicitly that this prescription gives a well defined (finite) force acting on particles in a class of perturbed infinite lattices, which are the point processes relevant to cosmological N -body simulations. For identical particles the dynamics of the simplest toy model (without expansion) is equivalent to that of an infinite set of points with inverted harmonic oscillator potentials which bounce elastically when they collide. We discuss and compare with previous results in the literature and present new results for the specific case of this simplest (static) model starting from "shuffled lattice" initial conditions. These show qualitative properties of the evolution (notably its "self-similarity") like those in the analogous simulations in three dimensions, which in turn resemble those in the expanding universe. PMID:19905274
Extremely correlated Fermi liquids in the limit of infinite dimensions
Perepelitsky, Edward Sriram Shastry, B.
2013-11-15
We study the infinite spatial dimensionality limit (d→∞) of the recently developed Extremely Correlated Fermi Liquid (ECFL) theory (Shastry 2011, 2013) [17,18] for the t–J model at J=0. We directly analyze the Schwinger equations of motion for the Gutzwiller projected (i.e. U=∞) electron Green’s function G. From simplifications arising in this limit d→∞, we are able to make several exact statements about the theory. The ECFL Green’s function is shown to have a momentum independent Dyson (Mori) self energy. For practical calculations we introduce a partial projection parameter λ, and obtain the complete set of ECFL integral equations to O(λ{sup 2}). In a related publication (Zitko et al. 2013) [23], these equations are compared in detail with the dynamical mean field theory for the large U Hubbard model. Paralleling the well known mapping for the Hubbard model, we find that the infinite dimensional t–J model (with J=0) can be mapped to the infinite-U Anderson impurity model with a self-consistently determined set of parameters. This mapping extends individually to the auxiliary Green’s function g and the caparison factor μ. Additionally, the optical conductivity is shown to be obtainable from G with negligibly small vertex corrections. These results are shown to hold to each order in λ. -- Highlights: •Infinite-dimensional t–J model (J=0) studied within new ECFL theory. •Mapping to the infinite U Anderson model with self consistent hybridization. •Single particle Green’s function determined by two local self energies. •Partial projection through control variable λ. •Expansion carried out to O(λ{sup 2}) explicitly.
Infinite single-particle bandwidth of a Mott-Hubbard insulator
NASA Astrophysics Data System (ADS)
Freericks, J. K.; Cohn, J. R.; van Dongen, P. G. J.; Krishnamurthy, H. R.
2016-03-01
The conventional viewpoint of the strongly correlated electron metal-insulator transition is that a single band splits into two upper and lower Hubbard bands at the transition. Much work has investigated whether this transition is continuous or discontinuous. Here we focus on another aspect and ask the question of whether there are additional upper and lower Hubbard bands, which stretch all the way out to infinity — leading to an infinite single-particle bandwidth (or spectral range) for the Mott insulator. While we are not able to provide a rigorous proof of this result, we use exact diagonalization studies on small clusters to motivate the existence of these additional bands, and we discuss some different methods that might be utilized to provide such a proof. Even though the extra upper and lower Hubbard bands have very low total spectral weight, those states are expected to have extremely long lifetimes, leading to a nontrivial contribution to the transport density of states for dc transport and modifying the high temperature limit for the electrical resistivity.
The EXTraS project: Exploring the X-ray Transient and variable Sky
NASA Astrophysics Data System (ADS)
De Luca, A.; Tiengo, A.; D'Agostino, D.; Watson, M.; Haberl, F.; Wilms, J.
2016-06-01
The EXTraS project is extracting the hitherto unexplored temporal domain information buried in the serendipitous data collected by XMM-Newton/EPIC since its launch. This includes a search for fast transients, missed by standard image analysis, as well as a search and characterization of variability (both periodic and aperiodic) in hundreds of thousands of sources, spanning more than nine orders of magnitude in time scale and six orders of magnitude in flux. Phenomenological classification of variable sources will also be performed. All our results, together with new analysis tools, will be made available to the community in an easy-to-use form at the end of 2016, with prospects of extending the analysis to future data. EXTraS products will have a very broad range of applications, from the search for rare events to population studies, with a large impact in almost all fields of astrophysics. This will boost the scientific exploitation of XMM data and make EPIC the reference for time-domain astronomy in the soft X-rays. The EXTraS project (2014-2016), funded within the EU/FP7 framework, is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany).
Unveiling long-term variability in XMM-Newton surveys within the EXTraS project
NASA Astrophysics Data System (ADS)
Rosen, S.; Read, A.; Law-Green, D.; Watson, M.; Pye, J.; O'Brien, P.
2016-06-01
The EXTraS project (Exploring the X-ray transient and variable sky) is an EU/FP7-Cooperation Space framework programme that aims to bring together a diverse set of time-domain analyses of XMM-Newton X-ray data and make them available to the public in a coherent manner. Through a combination of pointed observations and slew scans, XMM-Newton has repeatedly observed many regions of the sky, in a few cases up to ˜50 times, ˜70000 sources being observed more than once. While non-uniformly spaced and often sparse, these snapshots provide scientifically valuable information on the photometric behaviour of sources on longer term (hours to ˜ a decade) timescales. Here we describe the collation of XMM-Newton data for long-term variability from the 3XMM-DR5 catalogue, the slew survey and upper-limit information from the associated XMM-Newton products, and the analysis being performed on the ensuing light curves. We also present emerging examples of some newly identified long-term variable sources to highlight the value of this element of the EXTraS project. These longer baseline light curves can (i) unveil variable sources that appear stable in individual observations, (ii) reveal exotic and transient sources and (iii) complement short-term variability information from elsewhere in the EXTraS project by probing slower physical phenomena.
One universal extra dimension in PYTHIA
NASA Astrophysics Data System (ADS)
ElKacimi, M.; Goujdami, D.; Przysiezniak, H.; Skands, P.
2010-01-01
The Universal Extra Dimensions model has been implemented in the PYTHIA generator from version 6.4.18 onwards, in its minimal formulation with one TeV -1-sized extra dimension. The additional possibility of gravity-mediated decays, through a variable number of eV -1-sized extra dimensions into which only gravity extends, is also available. The implementation covers the lowest lying Kaluza-Klein (KK) excitations of Standard Model particles, except for the excitations of the Higgs fields, with the mass spectrum calculated at one loop. 2→2 tree-level production cross sections and unpolarized KK number conserving 2-body decays are included. Mixing between iso-doublet and -singlet KK excitations is neglected thus far, and is expected to be negligible for all but the top sector. New version summaryProgram title: PYTHIA Version number: 6.420 Catalogue identifier: ACTU_v2_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ACTU_v2_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 79 362 No. of bytes in distributed program, including test data, etc.: 590 900 Distribution format: tar.gz Programming language: Fortran 77 Computer: CERN lxplus and any other machine with a Fortran 77 compiler Operating system: Linux Red Hat RAM: about 800 K words Word size: 32 bits Classification: 11.2 Catalogue identifier of previous version: ACTU_v2_0 Journal reference of previous version: Comput. Phys. Comm. 135 (2001) 238 Does the new version supersede the previous version?: Yes Nature of problem: At high energy collisions between elementary particles, physics beyond the Standard Model is searched for. Many models are being investigated, namely extra-dimensional models. Solution method: The Universal Extra Dimension model is implemented in the PYTHIA event generator. Reasons for new version
Intra-Extra Vehicular Activity Apollo Spacesuits
NASA Technical Reports Server (NTRS)
Thomas, Kenneth S.
2016-01-01
Kenneth Thomas will discuss the Apollo Intra-Extra Vehicular Activity (IEVA) spacesuits, which supported launch and reentry and extra-vehicular activity. This program was NASA's first attempt to develop a new suit design from requirements and concepts. Mr. Thomas will chronicle the challenges, developments, struggles, and solutions that culminated in the system that allowed the first human exploration of the Moon and deep space (outside low-Earth orbit). Apollo pressure suit designs allowed the heroic repair of the Skylab space station and supported the first U.S. and Russian spacecraft docking during the Apollo Soyuz Test Project. Mr. Thomas will also discuss the IEVA suits' successes and challenges associated with the IEVA developments of the 1960s.
Brane modeling in warped extra-dimension
NASA Astrophysics Data System (ADS)
Ahmed, Aqeel; Grzadkowski, Bohdan
2013-01-01
Five-dimensional scenarios with infinitesimally thin branes replaced by appropriate configurations of a scalar field were considered. A possibility of periodic extra dimension was discussed in the presence on non-minimal scalar-gravity coupling and a generalized Gibbons-Kallosh-Linde sum rule was found. In order to avoid constraints imposed by periodicity, a non-compact spacial extra dimension was introduced. A five dimensional model with warped geometry and two thin branes mimicked by a scalar profile was constructed and discussed. In the thin brane limit the model corresponds to a set-up with two positive-tension branes. The presence of two branes allows to address the issue of the hierarchy problem which could be solved by the standard warping of the four dimensional metric provided the Higgs field is properly localized. Stability of the background solution was discussed and verified in the presence of the most general perturbations of the metric and the scalar field.
Extra-pair paternity in waved albatrosses.
Huyvaert, K P; Anderson, D J; Jones, T C; Duan, W; Parker, P G
2000-09-01
We estimated the rate of extra-pair fertilizations (EPFs) in waved albatrosses (Phoebastria irrorata) on Isla Española, Galápagos, Ecuador, using multilocus minisatellite DNA fingerprinting. Waved albatrosses are socially monogamous, long-lived seabirds whose main population is on Española. Aggressive extra-pair copulation (EPC) attempts have been observed in the breeding colony during the days preceding egg-laying. Our genetic analyses of 16 families (single chicks and their attending parents) revealed evidence of EPFs in four families. In all cases males were the excluded parent. These data suggest that waved albatrosses have an unusually high rate of EPF relative to taxa with similar life histories. Future behavioural observations will determine the extent to which forced vs. unforced EPCs contribute to this high EPF rate. PMID:10972780
Conformal field theories with infinitely many conservation laws
Todorov, Ivan
2013-02-15
Globally conformal invariant quantum field theories in a D-dimensional space-time (D even) have rational correlation functions and admit an infinite number of conserved (symmetric traceless) tensor currents. In a theory of a scalar field of dimension D-2 they were demonstrated to be generated by bilocal normal products of free massless scalar fields with an O(N), U(N), or Sp(2N) (global) gauge symmetry [B. Bakalov, N. M. Nikolov, K.-H. Rehren, and I. Todorov, 'Unitary positive energy representations of scalar bilocal fields,' Commun. Math. Phys. 271, 223-246 (2007); e-print arXiv:math-ph/0604069v3; and 'Infinite dimensional Lie algebras in 4D conformal quantum field theory,' J. Phys. A Math Theor. 41, 194002 (2008); e-print arXiv:0711.0627v2 [hep-th
Infinite-Order Symmetries for Quantum Separable Systems
Miller, W.; Kalnins, E.G.; Kress, J.M.; Pogosyan, G.S.
2005-10-01
We develop a calculus to describe the (in general) infinite-order differential operator symmetries of a nonrelativistic Schroedinger eigenvalue equation that admits an orthogonal separation of variables in Riemannian n space. The infinite-order calculus exhibits structure not apparent when one studies only finite-order symmetries. The search for finite-order symmetries can then be reposed as one of looking for solutions of a coupled system of PDEs that are polynomial in certain parameters. Among the simple consequences of the calculus is that one can generate algorithmically a canonical basis for the space. Similarly, we can develop a calculus for conformal symmetries of the time-dependent Schroedinger equation if it admits R separation in some coordinate system. This leads to energy-shifting symmetries.
Approximation of Optimal Infinite Dimensional Compensators for Flexible Structures
NASA Technical Reports Server (NTRS)
Gibson, J. S.; Mingori, D. L.; Adamian, A.; Jabbari, F.
1985-01-01
The infinite dimensional compensator for a large class of flexible structures, modeled as distributed systems are discussed, as well as an approximation scheme for designing finite dimensional compensators to approximate the infinite dimensional compensator. The approximation scheme is applied to develop a compensator for a space antenna model based on wrap-rib antennas being built currently. While the present model has been simplified, it retains the salient features of rigid body modes and several distributed components of different characteristics. The control and estimator gains are represented by functional gains, which provide graphical representations of the control and estimator laws. These functional gains also indicate the convergence of the finite dimensional compensators and show which modes the optimal compensator ignores.
Accelerated Gibbs Sampling for Infinite Sparse Factor Analysis
Andrzejewski, D M
2011-09-12
The Indian Buffet Process (IBP) gives a probabilistic model of sparse binary matrices with an unbounded number of columns. This construct can be used, for example, to model a fixed numer of observed data points (rows) associated with an unknown number of latent features (columns). Markov Chain Monte Carlo (MCMC) methods are often used for IBP inference, and in this technical note, we provide a detailed review of the derivations of collapsed and accelerated Gibbs samplers for the linear-Gaussian infinite latent feature model. We also discuss and explain update equations for hyperparameter resampling in a 'full Bayesian' treatment and present a novel slice sampler capable of extending the accelerated Gibbs sampler to the case of infinite sparse factor analysis by allowing the use of real-valued latent features.
Predictive Rate-Distortion for Infinite-Order Markov Processes
NASA Astrophysics Data System (ADS)
Marzen, Sarah E.; Crutchfield, James P.
2016-05-01
Predictive rate-distortion analysis suffers from the curse of dimensionality: clustering arbitrarily long pasts to retain information about arbitrarily long futures requires resources that typically grow exponentially with length. The challenge is compounded for infinite-order Markov processes, since conditioning on finite sequences cannot capture all of their past dependencies. Spectral arguments confirm a popular intuition: algorithms that cluster finite-length sequences fail dramatically when the underlying process has long-range temporal correlations and can fail even for processes generated by finite-memory hidden Markov models. We circumvent the curse of dimensionality in rate-distortion analysis of finite- and infinite-order processes by casting predictive rate-distortion objective functions in terms of the forward- and reverse-time causal states of computational mechanics. Examples demonstrate that the resulting algorithms yield substantial improvements.
Infinite number of MSSMs from heterotic line bundles?
NASA Astrophysics Data System (ADS)
Groot Nibbelink, Stefan; Loukas, Orestis; Ruehle, Fabian; Vaudrevange, Patrick K. S.
2015-08-01
We consider heterotic E8×E8 supergravity compactified on smooth Calabi-Yau manifolds with line bundle gauge backgrounds. Infinite sets of models that satisfy the Bianchi identities and flux quantization conditions can be constructed by letting their background flux quanta grow without bound. Even though we do not have a general proof, we find that all examples are at the boundary of the theory's validity: the Donaldson-Uhlenbeck-Yau equations, which can be thought of as vanishing D-term conditions, cannot be satisfied inside the Kähler cone unless a growing number of scalar vacuum expectation values is switched on. As they are charged under various line bundles simultaneously, the gauge background gets deformed by these VEVs to a non-Abelian bundle. In general, our physical expectation is that such infinite sets of models should be impossible, since they never seem to occur in exact conformal field theory constructions.
LES investigation of infinite staggered wind-turbine arrays
NASA Astrophysics Data System (ADS)
Yang, Xiaolei; Sotiropoulos, Fotis
2014-12-01
The layouts of turbines affect the turbine wake interactions and thus the wind farm performance. The wake interactions in infinite staggered wind-turbine arrays are investigated and compared with infinite aligned turbine arrays in this paper. From the numerical results we identify three types of wake behaviours, which are significantly different from wakes in aligned wind-turbine arrays. For the first type, each turbine wake interferes with the pair of staggered downstream turbine wakes and the aligned downstream turbine. For the second type, each turbine wake interacts with the first two downstream turbine wakes but does not show significant interference with the second aligned downstream turbine. For the third type, each turbine wake recovers immediately after passing through the gap of the first two downstream turbines and has little interaction with the second downstream turbine wakes The extracted power density and power efficiency are also studied and compared with aligned wind-turbine arrays.
The development of infinitives from three to five.
Eisenberg, S L; Cairns, H S
1994-10-01
This study investigated the form of infinitival sentences produced by young children and their knowledge of the control properties of this sentence form. Twenty-five children between the ages of 3;7 and 5;4 participated in a story completion task designed to elicit infinitive sentences and in an act-out comprehension task. Although the infinitive form was productive for even the youngest children in this study, development of this form was not complete even for the five-year-olds, nor did any child demonstrate adult knowledge of control. In addition, two competing claims regarding order of acquisition (that of Limber, 1973, and Hyams, 1985) were evaluated. PMID:7852479
Predictive Rate-Distortion for Infinite-Order Markov Processes
NASA Astrophysics Data System (ADS)
Marzen, Sarah E.; Crutchfield, James P.
2016-06-01
Predictive rate-distortion analysis suffers from the curse of dimensionality: clustering arbitrarily long pasts to retain information about arbitrarily long futures requires resources that typically grow exponentially with length. The challenge is compounded for infinite-order Markov processes, since conditioning on finite sequences cannot capture all of their past dependencies. Spectral arguments confirm a popular intuition: algorithms that cluster finite-length sequences fail dramatically when the underlying process has long-range temporal correlations and can fail even for processes generated by finite-memory hidden Markov models. We circumvent the curse of dimensionality in rate-distortion analysis of finite- and infinite-order processes by casting predictive rate-distortion objective functions in terms of the forward- and reverse-time causal states of computational mechanics. Examples demonstrate that the resulting algorithms yield substantial improvements.
Dimensional reduction without continuous extra dimensions
Chamseddine, Ali H.; Froehlich, J.; Schubnel, B.; Wyler, D.
2013-01-15
We describe a novel approach to dimensional reduction in classical field theory. Inspired by ideas from noncommutative geometry, we introduce extended algebras of differential forms over space-time, generalized exterior derivatives, and generalized connections associated with the 'geometry' of space-times with discrete extra dimensions. We apply our formalism to theories of gauge- and gravitational fields and find natural geometrical origins for an axion- and a dilaton field, as well as a Higgs field.
Cystic lesions accompanying extra-axial tumours.
Lohle, P N; Wurzer, H A; Seelen, P J; Kingma, L M; Go, K G
1999-01-01
We examined the mechanism of cyst formation in extra-axial tumours in the central nervous system (CNS). Cyst fluid, cerebrospinal fluid (CSF) and blood plasma were analysed in eight patients with nine peritumoral cysts: four with meningiomas, two with intracranial and two spinal intradural schwannomas. Measuring concentrations of various proteins [albumin, immunoglobulin G (IgG), IgA, alpha 2-macroglobulin and IgM] in cyst fluid, CSF and blood plasma provides insight into the state of the semipermeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier. Peritumoral cysts accompanying intra-axial brain tumours are the end result of disruption of the BBB and oedema formation. Unlike intra-axial tumours which lie embedded within nervous tissue, extra-axial tumours tend to be separated from nervous tissue by arachnoid and pia mater. High concentrations of proteins were measured in the cyst fluid, approaching blood plasma levels, suggesting a local barrier disruption, and passage across the arachnoid, pia mater and cortical/medullary layer into the CNS parenchyma, leaving the protein concentrations of CSF practically unchanged. We confirmed that very high concentrations of protein are to be found in tumour cysts, plasma proteins forming almost 90% of the total protein in the cyst. We review current hypotheses on the pathogenesis of cysts accompanying neoplasms, particularly meningiomas and schwannomas, and conclude that the majority of proteins in cyst fluid in extra-axial, intradural meningiomas and schwannomas are plasma proteins. This provides a strong argument for pathogenesis of extra-axial intradural tumour cysts in favour of leakage of plasma proteins out of the tumour vessels into the nervous tissue. PMID:9987761
Signals for Extra Dimensions at CLIC
Rizzo, Thomas G.
2001-08-28
A brief overview is presented of the signatures for several different models with extra dimensions at CLIC, an e{sup +}e{sup -} linear collider with a center of mass energy of 3-5 TeV and an integrated luminosity of order 1 ab{sup -1}. In all cases the search reach for the resulting new physic signatures is found to be in the range of {approx} 15-80 TeV.
Kinks, extra dimensions, and gravitational waves
O'Callaghan, Eimear; Gregory, Ruth
2011-03-01
We investigate in detail the gravitational wave signal from kinks on cosmic (super)strings, including the kinematical effects from the internal extra dimensions. We find that the signal is suppressed, however, the effect is less significant that that for cusps. Combined with the greater incidence of kinks on (super)strings, it is likely that the kink signal offers the better chance for detection of cosmic (super)strings.
Subdifferential of Optimal Value Functions in Nonlinear Infinite Programming
Huy, N. Q. Giang, N. D.; Yao, J.-C.
2012-02-15
This paper presents an exact formula for computing the normal cones of the constraint set mapping including the Clarke normal cone and the Mordukhovich normal cone in infinite programming under the extended Mangasarian-Fromovitz constraint qualification condition. Then, we derive an upper estimate as well as an exact formula for the limiting subdifferential of the marginal/optimal value function in a general Banach space setting.
Global Stability for Infinite Delay Lotka-Volterra Type Systems
NASA Astrophysics Data System (ADS)
Kuang, Y.; Smith, H. L.
1993-06-01
In this paper, sufficient conditions are established for the global stability of the saturated equilibrium of an infinite delay, nonautonomous Lotka-Volterra type system. The present work is distinguished from previous work principally be allowing the system to be nonautonomous and relaxing the traditional requirement that the undelayed intraspecific competition dominates both the delayed intraspecific competition as well as the interspecific interactions. We require the undelayed intraspecific competition to dominate the latter but not the former.
Analysis of Multiple Cracks in an Infinite Functionally Graded Plate
NASA Technical Reports Server (NTRS)
Shbeeb, N. I.; Binienda, W. K.; Kreider, K. L.
1999-01-01
A general methodology was constructed to develop the fundamental solution for a crack embedded in an infinite non-homogeneous material in which the shear modulus varies exponentially with the y coordinate. The fundamental solution was used to generate a solution to fully interactive multiple crack problems for stress intensity factors and strain energy release rates. Parametric studies were conducted for two crack configurations. The model displayed sensitivity to crack distance, relative angular orientation, and to the coefficient of nonhomogeneity.
Some characterizations of quantum channel in infinite Hilbert spaces
Sun, Xiu-Hong; Li, Yuan
2014-05-15
We first show that for any quantum states ρ on H and σ on K there exists a quantum channel Φ such that Φ(ρ) = σ, where H and K are finite or infinite dimensional Hilbert spaces. Then we consider some conclusions for the quantum channel Φ such that Φ(ρ) = σ and Φ(I{sub H}) exists or Φ(I{sub H})=I{sub K}.
Extra Large Temporal Tunnel Cataract Extraction [ETCE
U., Vivekanand
2014-01-01
Purpose: To determine the outcomes of extra large temporal sclero-corneal tunnel incision Cataract Surgery. Materials and Methods: This consecutive case series of eyes undergoing temporal tunnel cataract extraction with tunnel length of 8 to 10 mm was identified retrospectively. Surgical procedure details, follow up, complications, visual and astigmatic outcomes at 6wks were recorded and analysed. Results: Ninety six eyes with extra large tunnel incision were identified for analysis from a dataset of 670 manual small incision cataract surgery cases. 58% eyes had NO5 or denser cataracts. Intraoperative complications included, tunnel related problems (1 eye, 1.04%), bleeding into Anterior Chamber (10 eyes, 10.4%), Posterior Capsular Rent (2 eyes, 2.1%). Early postoperative complications included striate keratopathy (7 eyes, 7.3%). The mean Best Corrected Visual Acuity was 6/7.5 (0.1 logMAR) and 98% cases had Best Corrected Visual Acuity of 6/12 (0.3 logMAR) or better at 6wk. The aggregate Surgically Induced Astigmatism was 0.32D at 850. Conclusion: Extra Large Tunnel of length 8 to 10 mm can be self sealing with low SIA. The complication rates and visual outcomes of ETCE are comparable to those of conventional MSICS. This method can be valuable in complicated cases and during learning period. PMID:25386505
19 CFR 151.64 - Extra copy of entry summary.
Code of Federal Regulations, 2014 CFR
2014-04-01
... TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair § 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate...
19 CFR 151.64 - Extra copy of entry summary.
Code of Federal Regulations, 2010 CFR
2010-04-01
... TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair § 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate...
19 CFR 151.64 - Extra copy of entry summary.
Code of Federal Regulations, 2013 CFR
2013-04-01
... TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair § 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate...
19 CFR 151.64 - Extra copy of entry summary.
Code of Federal Regulations, 2012 CFR
2012-04-01
... TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair § 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate...
19 CFR 151.64 - Extra copy of entry summary.
Code of Federal Regulations, 2011 CFR
2011-04-01
... TREASURY (CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair § 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate...
Analysis of transitional separation bubbles on infinite swept wings
NASA Technical Reports Server (NTRS)
Davis, R. L.; Carter, J. E.
1986-01-01
A previously developed two-dimensional local inviscid-viscous interaction technique for the analysis of airfoil transitional separation bubbles, ALESEP (Airfoil Leading Edge Separation), has been extended for the calculation of transitional separation bubbles over infinite swept wings. As part of this effort, Roberts' empirical correlation, which is interpreted as a separated flow empirical extension of Mack's stability theory for attached flows, has been incorporated into the ALESEP procedure for the prediction of the transition location within the separation bubble. In addition, the viscous procedure used in the ALESEP techniques has been modified to allow for wall suction. A series of two-dimensional calculations is presented as a verification of the prediction capability of the interaction techniques with the Roberts' transition model. Numerical tests have shown that this two-dimensional natural transition correlation may also be applied to transitional separation bubbles over infinite swept wings. Results of the interaction procedure are compared with Horton's detailed experimental data for separated flow over a swept plate which demonstrates the accuracy of the present technique. Wall suction has been applied to a similar interaction calculation to demonstrate its effect on the separation bubble. The principal conclusion of this paper is that the prediction of transitional separation bubbles over two-dimensional or infinite swept geometries is now possible using the present interacting boundary layer approach.
Single file diffusion into a semi-infinite tube
NASA Astrophysics Data System (ADS)
Farrell, Spencer G.; Brown, Aidan I.; Rutenberg, Andrew D.
2015-12-01
We investigate single file diffusion (SFD) of large particles entering a semi-infinite tube, such as luminal diffusion of proteins into microtubules or flagella. While single-file effects have no impact on the evolution of particle density, we report significant single-file effects for individually tracked tracer particle motion. Both exact and approximate ordering statistics of particles entering semi-infinite tubes agree well with our stochastic simulations. Considering initially empty semi-infinite tubes, with particles entering at one end starting from an initial time t = 0, tracked particles are initially super-diffusive after entering the system, but asymptotically diffusive at later times. For finite time intervals, the ratio of the net displacement of individual single-file particles to the average displacement of untracked particles is reduced at early times and enhanced at later times. When each particle is numbered, from the first to enter (n = 1) to the most recent (n = N), we find good scaling collapse of this distance ratio for all n. Experimental techniques that track individual particles, or local groups of particles, such as photo-activation or photobleaching of fluorescently tagged proteins, should be able to observe these single-file effects. However, biological phenomena that depend on local concentration, such as flagellar extension or luminal enzymatic activity, should not exhibit single-file effects.
Single file diffusion into a semi-infinite tube.
Farrell, Spencer G; Brown, Aidan I; Rutenberg, Andrew D
2015-12-01
We investigate single file diffusion (SFD) of large particles entering a semi-infinite tube, such as luminal diffusion of proteins into microtubules or flagella. While single-file effects have no impact on the evolution of particle density, we report significant single-file effects for individually tracked tracer particle motion. Both exact and approximate ordering statistics of particles entering semi-infinite tubes agree well with our stochastic simulations. Considering initially empty semi-infinite tubes, with particles entering at one end starting from an initial time t = 0, tracked particles are initially super-diffusive after entering the system, but asymptotically diffusive at later times. For finite time intervals, the ratio of the net displacement of individual single-file particles to the average displacement of untracked particles is reduced at early times and enhanced at later times. When each particle is numbered, from the first to enter (n = 1) to the most recent (n = N), we find good scaling collapse of this distance ratio for all n. Experimental techniques that track individual particles, or local groups of particles, such as photo-activation or photobleaching of fluorescently tagged proteins, should be able to observe these single-file effects. However, biological phenomena that depend on local concentration, such as flagellar extension or luminal enzymatic activity, should not exhibit single-file effects. PMID:26595123
Finite and infinite wavelength elastocapillary instabilities with cylindrical geometry
NASA Astrophysics Data System (ADS)
Biggins, John; Xuan, Chen
In an elastic cylinder with shear modulus μ, radius R0 and surface tension γ we can define an emergent elastocapillary length l = γ / μ . When this length becomes comparable to R0 the cylinder becomes undergoes a Rayleigh-Plateaux type instability, but surprisingly, with infinite wavelength λ rather than with wavelength λ ~R0 ~ l . Here we take advantage of this infinite wavelength behaviour to construct a simple 1-D model of the elastocapillary instability in a cylindrical gel which permits a high-amplitude fully non-linear treatment. In particular, we show that the instability is sub-critical and entirely dependent on the elastic cylinder being subject to tension. We also discuss elastocapillary instabilities in a range of other cylindrical geometries, such a cylindrical cavities through a bulk elastic solid, or a solid cylinder embedded in a bulk elastic solid, and show that in these cases instability has finite wavelength. Thus infinite wavelength behaviour is a curiosity of elastic cylinders rather than the generic behaviour or elasto-capiliarity. Also Fudan University Shanghai.
Infinite variance in fermion quantum Monte Carlo calculations
NASA Astrophysics Data System (ADS)
Shi, Hao; Zhang, Shiwei
2016-03-01
For important classes of many-fermion problems, quantum Monte Carlo (QMC) methods allow exact calculations of ground-state and finite-temperature properties without the sign problem. The list spans condensed matter, nuclear physics, and high-energy physics, including the half-filled repulsive Hubbard model, the spin-balanced atomic Fermi gas, and lattice quantum chromodynamics calculations at zero density with Wilson Fermions, and is growing rapidly as a number of problems have been discovered recently to be free of the sign problem. In these situations, QMC calculations are relied on to provide definitive answers. Their results are instrumental to our ability to understand and compute properties in fundamental models important to multiple subareas in quantum physics. It is shown, however, that the most commonly employed algorithms in such situations have an infinite variance problem. A diverging variance causes the estimated Monte Carlo statistical error bar to be incorrect, which can render the results of the calculation unreliable or meaningless. We discuss how to identify the infinite variance problem. An approach is then proposed to solve the problem. The solution does not require major modifications to standard algorithms, adding a "bridge link" to the imaginary-time path integral. The general idea is applicable to a variety of situations where the infinite variance problem may be present. Illustrative results are presented for the ground state of the Hubbard model at half-filling.
Symmetry-protected local minima in infinite DMRG
NASA Astrophysics Data System (ADS)
Pfeifer, Robert N. C.
2015-11-01
The infinite density matrix renormalization group (iDMRG) algorithm is a highly successful numerical algorithm for the study of low-dimensional quantum systems, and is also frequently used to initialize the more popular finite DMRG algorithm. Implementations of both finite and infinite DMRG frequently incorporate support for the protection and exploitation of symmetries of the Hamiltonian. In common with other variational tensor network algorithms, convergence of iDMRG to the ground state is not guaranteed, with the risk that the algorithm may become stuck in a local minimum. In this paper, I demonstrate the existence of a particularly harmful class of physically irrelevant local minima affecting both iDMRG and to a lesser extent also infinite time-evolving block decimation (iTEBD), for which the ground state is compatible with the protected symmetries of the Hamiltonian but cannot be reached using the conventional iDMRG or iTEBD algorithms. I describe a modified iDMRG algorithm which evades these local minima, and which also admits a natural interpretation on topologically ordered systems with a boundary.
Infinite slope stability under steady unsaturated seepage conditions
Lu, N.; Godt, J.
2008-01-01
[1] We present a generalized framework for the stability of infinite slopes under steady unsaturated seepage conditions. The analytical framework allows the water table to be located at any depth below the ground surface and variation of soil suction and moisture content above the water table under steady infiltration conditions. The framework also explicitly considers the effect of weathering and porosity increase near the ground surface on changes in the friction angle of the soil. The factor of safety is conceptualized as a function of the depth within the vadose zone and can be reduced to the classical analytical solution for subaerial infinite slopes in the saturated zone. Slope stability analyses with hypothetical sandy and silty soils are conducted to illustrate the effectiveness of the framework. These analyses indicate that for hillslopes of both sandy and silty soils, failure can occur above the water table under steady infiltration conditions, which is consistent with some field observations that cannot be predicted by the classical infinite slope theory. A case study of shallow slope failures of sandy colluvium on steep coastal hillslopes near Seattle, Washington, is presented to examine the predictive utility of the proposed framework. Copyright 2008 by the American Geophysical Union.
46 CFR Sec. 8 - Extra work and changes.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 8 2010-10-01 2010-10-01 false Extra work and changes. Sec. 8 Section 8 Shipping... Sec. 8 Extra work and changes. (a) At any time after the award of an original job order and during the time the work thereunder is being performed, additional or extra work or changes in the work covered...
46 CFR Sec. 8 - Extra work and changes.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 8 2011-10-01 2011-10-01 false Extra work and changes. Sec. 8 Section 8 Shipping... Sec. 8 Extra work and changes. (a) At any time after the award of an original job order and during the time the work thereunder is being performed, additional or extra work or changes in the work covered...
ERIC Educational Resources Information Center
Harris, J. R.
1973-01-01
Discusses applications of techniques developed for the remote sensing of infrared radiation. In addition to military applications, remote sensing has become important in collecting environmental data and detecting ecological problems. (JR)
Modality, Infinitives, and Finite Bare Verbs in Dutch and English Child Language
ERIC Educational Resources Information Center
Blom, Elma
2007-01-01
This article focuses on the meaning of nonfinite clauses ("root infinitives") in Dutch and English child language. I present experimental and naturalistic data confirming the claim that Dutch root infinitives are more often modal than English root infinitives. This cross-linguistic difference is significantly smaller than previously assumed,…
Synthesis of highly stable metal-containing extra-large-pore molecular sieves.
Martínez-Franco, Raquel; Paris, Cecilia; Moliner, Manuel; Corma, Avelino
2016-02-28
The isomorphic substitution of two different metals (Mg and Co) within the framework of the ITQ-51 zeotype (IFO structure) using bulky aromatic proton sponges as organic structure-directing agents (OSDAs) has allowed the synthesis of different stable metal-containing extra-large-pore zeotypes with high pore accessibility and acidity. These metal-containing extra-large-pore zeolites, named MgITQ-51 and CoITQ-51, have been characterized by different techniques, such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, UV-Vis spectroscopy, temperature programmed desorption of ammonia and Fourier transform infrared spectroscopy, to study their physico-chemical properties. The characterization confirms the preferential insertion of Mg and Co atoms within the crystalline structure of the ITQ-51 zeotype, providing high Brønsted acidity, and allowing their use as efficient heterogeneous acid catalysts in industrially relevant reactions involving bulky organic molecules. PMID:26755759
Quantification of adulterations in extra virgin flaxseed oil using MIR and PLS.
de Souza, Letícia Maria; de Santana, Felipe Bachion; Gontijo, Lucas Caixeta; Mazivila, Sarmento Júnior; Borges Neto, Waldomiro
2015-09-01
This paper proposes a new method for the quantitative analysis of soybean oil (SO) and sunflower oil (SFO) as adulterants in extra virgin flaxseed oil (EFO) by applying Mid Infrared Spectroscopy (MIR) associated with chemometric technique of Partial Least Squares (PLS). The PLS models were built in accordance with standard method ASTM E1655-05 and these showed good correlation between the reference values and those calculated using the PLS models with low error values, with R = 0.998 for SFO and R = 0.999 for SO in EFO. These models were validated analytically in accordance with Brazilian and international guidelines through the estimate of figures of merit parameters, thus showing an effective and feasible method to control the quality of extra virgin flaxseed oil. PMID:25842305
Extra relativistic degrees of freedom without extra particles using Planck data
NASA Astrophysics Data System (ADS)
Mastache, Jorge; de la Macorra, Axel
2013-08-01
A recent number of analyses of cosmological data have shown indications for the presence of extra radiation beyond the standard model at the equality and nucleosynthesis epochs, which has been usually interpreted as an effective number of neutrinos, Neff>3.046. In this work we establish the theoretical basis for a particle physics-motivated model (bound dark matter, BDM) which explains the need for extra radiation. The BDM model describes dark matter particles which are relativistic at a scale below a
Radio communications with extra-terrestrial civilizations
NASA Technical Reports Server (NTRS)
Kotelnikov, V. A.
1974-01-01
Communications between civilizations within our galaxy at the present level of radio engineering is possible, although civilizations must begin to search for each other to achieve this. If an extra-terrestrial civilization possessing a technology at our level wishes to make itself known and will transmit special radio signals to do this, then it can be picked up by us at a distance of several hundreds of light years using already existing radio telescopes and specially built radio receivers. If it wishes, this civilization can also send us information without awaiting our answer.
Large Extra Dimension and Dark Matter Detection
Qin Bo; Starkman, Glenn D.; Silk, Joseph
2008-01-03
If our space has the large extra dimensions as proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD), then gravity would start to deviate from Newtonian gravity and be greatly enhanced in sub-millimeter scales. Here we show that in the ADD scenario, gravity could play an important role (compared to the weak interaction) in the interactions between dark matter particles and the electron. We find that for typical WIMP dark matter, such dark matter-electron 'gravitational' scattering cross section may be much larger than the dark matter-nucleon cross section constrained by current dark matter experiments.
Direct imaging of extra-solar planets
Olivier, S.S.; Max, V.E.; Brase, J.M.; Caffano, C.J.; Gavel, D.T.; Macintosh, B.A.
1997-03-01
Direct imaging of extra-solar planets may be possible with the new generation of large ground-based telescopes equipped with state- of- the-art adaptive optics (AO) systems to compensate for the blurring effect of the Earth`s atmosphere. The first of these systems is scheduled to begin operation in 1998 on the 10 in Keck II telescope. In this paper, general formulas for high-contrast imaging with AO systems are presented and used to calculate the sensitivity of the Keck AO system. The results of these calculations show that the Keck AO system should achieve the sensitivity necessary to detect giant planets around several nearby bright stars.
Laryngeal Leishmaniasis with Extra-pulmonary Tuberculosis.
Tayal, Swati; Khatiwada, Saurav; Sehrawat, Priyanka; Nischal, Neeraj; Jorwal, Pankaj; Soneja, Manish; Sharma, M C; Sharma, S K; Verma, Pankaj; Singh, Anup
2015-09-01
Clinical presentations of Leishmania infection include visceral (most common form), cutaneous, mucocutaneous, mucosal and post-kala-azar dermal leishmaniasis. Mucosal form of leishmaniasis mostly involves oral and nasal mucosa. Rarely, laryngeal and pharyngeal mucosa may also be involved. Its concomitant presence with tuberculosis (TB), a disease rampant in India, is uncommon. Here we are reporting a case of isolated laryngeal leishmaniasis associated with extra-pulmonary tuberculosis (EPTB), with approach to diagnosis and treatment in a tropical resource-limited setting. PMID:27608871
Large Extra Dimension and Dark Matter Detection
NASA Astrophysics Data System (ADS)
Qin, Bo; Starkman, Glenn D.; Silk, Joseph
2008-01-01
If our space has the large extra dimensions as proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD), then gravity would start to deviate from Newtonian gravity and be greatly enhanced in sub-millimeter scales. Here we show that in the ADD scenario, gravity could play an important role (compared to the weak interaction) in the interactions between dark matter particles and the electron. We find that for typical WIMP dark matter, such dark matter-electron ``gravitational'' scattering cross section may be much larger than the dark matter-nucleon cross section constrained by current dark matter experiments.
The EXTraS project: Exploring the X-ray Transient and variable Sky
NASA Astrophysics Data System (ADS)
De Luca, Andrea; EXTraS Collaboration
2015-09-01
EXTraS (EU-FP7 framework) is the first systematic search for (and characterization of) all variable soft X-ray sources at all time scales in the whole archive of observations collected by the EPIC instrument on-board XMM-Newton since its launch in 1999, looking for transients, aperiodic, periodic and long-term variability. The project includes the phenomenological classification of all detected variable sources, extending and improving the 3XMM catalalogue. All results will be released in a public archive, together with new software tools.
Spring back of infinite honeycomb sheets beyond plastic deformation
NASA Astrophysics Data System (ADS)
Bonfanti, A.; Bhaskar, A.
2015-02-01
Cellular structures are promising for applications where high stiffness and strength are required with the minimal use of material. They are often used in applications where the plastic deformation plays an important role, such as those involving crashworthiness, energy absorption, and stents. The elastic analysis of a honeycomb sheet has been carried out in the past [1]. The present analysis extends this classical work in the elasto-plastic regime. Recoil analysis due to elastic recovery is absent from the published literature. This work aims to develop an analytical model to calculate the spring back for a simplified case, that of an infinite honeycomb sheet. An elastic-perfectly plastic material model is assumed. The recoil for a clamped beam with a load and moment applied at the free edge is analytically calculated first. This is carried out by relating the stress distribution of the cross section to the final deformed shape. The part corresponding to the elastic contribution is subsequently subtracted in order to obtain the final configuration after the external load is removed. This simple elasto-plastic analysis is then incorporated into the analysis of an infinite sheet made of uniform hexagonal cells. The translational symmetry of the lattice is exploited along with the analysis of a beam under tip loading through to plastic stage and recoil. The final shape of the struts upon the removal of the remote stress is completely determined by the plastic deformation which cannot be recovered. The expression for the beam thus obtained is then used to build an analytical model for an infinite honeycomb sheet loaded in both directions.
Rotor-router walk on a semi-infinite cylinder
NASA Astrophysics Data System (ADS)
Papoyan, Vl V.; Poghosyan, V. S.; Priezzhev, V. B.
2016-07-01
We study the rotor-router walk with the clockwise ordering of outgoing edges on the semi-infinite cylinder. Imposing uniform conditions on the boundary of the cylinder, we consider growth of the cluster of visited sites and its internal structure. The average width of the surface region of the cluster evolves with time to the stationary value by a scaling law whose parameters are close to the standard KPZ exponents. We introduce characteristic labels corresponding to closed clockwise contours formed by rotors and show that the sequence of labels has in average an ordered helix structure.
Anomalous properties of the Hubbard model in infinite dimensions
NASA Astrophysics Data System (ADS)
Jarrell, M.; Pruschke, Th.
1994-01-01
Anomalies are found in the resistivity ρ and NMR rate 1/T1 of the infinite-dimensional Hubbard model using quantum Monte Carlo calculations and the noncrossing approximation. For temperatures greater than the ``Kondo scale'' T0, we obtain 1/T1~a+bT and ρ~c+dT (a, b, c, d constants). For temperatures T<
Scan blindness in infinite phased arrays of printed dipoles
NASA Technical Reports Server (NTRS)
Pozar, D. M.; Schaubert, D. H.
1984-01-01
A comprehensive study of infinite phased arrays of printed dipole antennas is presented, with emphasis on the scan blindness phenomenon. A rigorous and efficient moment method procedure is used to calculate the array impedance versus scan angle. Data are presented for the input reflection coefficient for various element spacings and substrate parameters. A simple theory, based on coupling from Floquet modes to surface wave modes on the substrate, is shown to predict the occurrence of scan blindness. Measurements from a waveguide simulator of a blindness condition confirm the theory.
Spin transport of weakly disordered Heisenberg chain at infinite temperature
NASA Astrophysics Data System (ADS)
Khait, Ilia; Gazit, Snir; Yao, Norman Y.; Auerbach, Assa
2016-06-01
We study the disordered Heisenberg spin chain, which exhibits many-body localization at strong disorder, in the weak to moderate disorder regime. A continued fraction calculation of dynamical correlations is devised, using a variational extrapolation of recurrents. Good convergence for the infinite chain limit is shown. We find that the local spin correlations decay at long times as C ˜t-β , whereas the conductivity exhibits a low-frequency power law σ ˜ωα . The exponents depict subdiffusive behavior β <1 /2 ,α >0 at all finite disorders and convergence to the scaling result α +2 β =1 at large disorders.
J-integral estimates for cracks in infinite bodies
NASA Technical Reports Server (NTRS)
Dowling, N. E.
1986-01-01
An analysis and discussion is presented of existing estimates of the J-integral for cracks in infinite bodies. Equations are presented which provide convenient estimates for Ramberg-Osgood type elastoplastic materials containing cracks and subjected to multiaxial loading. The relationship between J and the strain normal to the crack is noted to be only weakly dependent on state of stress. But the relationship between J and the stress normal to the crack is strongly dependent on state of stress. A plastic zone correction term often employed is found to be arbitrary, and its magnitude is seldom significant.
Infinite impulse response modal filtering in visible adaptive optics
NASA Astrophysics Data System (ADS)
Agapito, G.; Arcidiacono, C.; Quirós-Pacheco, F.; Puglisi, A.; Esposito, S.
2012-07-01
Diffraction limited resolution adaptive optics (AO) correction in visible wavelengths requires a high performance control. In this paper we investigate infinite impulse response filters that optimize the wavefront correction: we tested these algorithms through full numerical simulations of a single-conjugate AO system comprising an adaptive secondary mirror with 1127 actuators and a pyramid wavefront sensor (WFS). The actual practicability of the algorithms depends on both robustness and knowledge of the real system: errors in the system model may even worsen the performance. In particular we checked the robustness of the algorithms in different conditions, proving that the proposed method can reject both disturbance and calibration errors.
Crack problems for a rectangular plate and an infinite strip
NASA Technical Reports Server (NTRS)
Civelek, M. B.; Erdogan, F.
1980-01-01
The general plane problem for an infinite strip containing multiple cracks perpendicular to its boundaries is considered. The problem is reduced to a system of singular integral equations. Two specific problems of practical interest are then studied in detail. The first problem explores the interaction effect of multiple edge cracks in a plate or beam under tension or bending. The second problem is that of a rectangular plate containing an arbitrarily oriented crack in the plane of symmetry. Particular emphasis is placed on the problem of a plate containing an edge crack and subjected to concentrated forces.
Limiting equilibrium and liquefaction potential in infinite submarine slopes
Denlinger, R.P.; Iverson, R.M.
1990-01-01
Stability evaluation of submarine slopes is hampered by the difficulty of making field measurements. Owing to the scarcity of detailed field data, stability is commonly assessed by assuming homogenous infinite slopes with steady seepage. For these conditions, it is necessary to measure only the slope angle, friction angle, cohesion, and pore pressure at some distance into the sediment to evaluate stability. Examination of available data shows that conditions close to those required for liquefaction are necessary for Coulomb failure in many continental shelf areas. This favors long landslide runouts and flow of sediment subsequent to failure. -from Authors
Flavor Structure of Warped Extra Dimension Models
Agashe, Kaustubh; Perez, Gilad; Soni, Amarjit
2004-08-10
We recently showed, in hep-ph/0406101, that warped extra dimensional models with bulk custodial symmetry and few TeV KK masses lead to striking signals at B-factories. In this paper, using a spurion analysis, we systematically study the flavor structure of models that belong to the above class. In particular we find that the profiles of the zero modes, which are similar in all these models, essentially control the underlying flavor structure. This implies that our results are robust and model independent in this class of models. We discuss in detail the origin of the signals in B-physics. We also briefly study other NP signatures that arise in rare K decays (K {yields} {pi}{nu}{nu}), in rare top decays [t {yields} c{gamma}(Z, gluon)] and the possibility of CP asymmetries in D{sup 0} decays to CP eigenstates such as K{sub s}{pi}{sup 0} and others. Finally we demonstrate that with light KK masses, {approx} 3 TeV, the above class of models with anarchic 5D Yukawas has a ''CP problem'' since contributions to the neutron electric dipole moment are roughly 20 times larger than the current experimental bound. Using AdS/CFT correspondence, these extra-dimensional models are dual to a purely 4D strongly coupled conformal Higgs sector thus enhancing their appeal.
Flavor structure of warped extra dimension models
NASA Astrophysics Data System (ADS)
Agashe, Kaustubh; Perez, Gilad; Soni, Amarjit
2005-01-01
We recently showed that warped extra-dimensional models with bulk custodial symmetry and few TeV Kaluza-Klein (KK) masses lead to striking signals at B factories. In this paper, using a spurion analysis, we systematically study the flavor structure of models that belong to the above class. In particular we find that the profiles of the zero modes, which are similar in all these models, essentially control the underlying flavor structure. This implies that our results are robust and model independent in this class of models. We discuss in detail the origin of the signals in B physics. We also briefly study other new physics signatures that arise in rare K decays (K→πνν), in rare top decays [t→cγ(Z,gluon)], and the possibility of CP asymmetries in D0 decays to CP eigenstates such as KSπ0 and others. Finally we demonstrate that with light KK masses, ˜3 TeV, the above class of models with anarchic 5D Yukawas has a “CP problem” since contributions to the neutron electric dipole moment are roughly 20 times larger than the current experimental bound. Using AdS/CFT correspondence, these extra-dimensional models are dual to a purely 4D strongly coupled conformal Higgs sector thus enhancing their appeal.
KK parity in warped extra dimension
NASA Astrophysics Data System (ADS)
Agashe, Kaustubh; Falkowski, Adam; Low, Ian; Servant, Géraldine
2008-04-01
We construct models with a Kaluza-Klein (KK) parity in a five-dimensional warped geometry, in an attempt to address the little hierarchy problem present in setups with bulk Standard Model fields. The lightest KK particle (LKP) is stable and can play the role of dark matter. We consider the possibilities of gluing two identical slices of AdS5 in either the UV (IR-UV-IR model) or the IR region (UV-IR-UV model) and discuss the model-building issues as well as phenomenological properties in both cases. In particular, we find that the UV-IR-UV model is not gravitationally stable and that additional mechanisms might be required in the IR-UV-IR model to address flavor issues. Collider signals of the warped KK parity are different from either the conventional warped extra dimension without KK parity, in which the new particles are not necessarily pair-produced, or the KK parity in flat universal extra dimensions, where each KK level is nearly degenerate in mass. Dark matter and collider properties of a TeV mass KK Z gauge boson as the LKP are discussed.
NASA Technical Reports Server (NTRS)
1997-01-01
A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.
Unveiling long-term variability in XMM-Newton surveys: the EXTraS project
NASA Astrophysics Data System (ADS)
Rosen, S.; Read, A.; De Luca, A.; EXTraS Collaboration
2014-07-01
The 3XMM-DR4 catalogue, the XMM-Newton Slew Survey (XSS) and the associated XMM-Newton EPIC data, are extensive resources for exploring high energy, time-domain astrophysics. Amongst these data are potential, hitherto unidentified variable sources, ranging from short duration (~seconds) transients through to objects varying on timescales of years. Variability signatures can be key to understanding the energetics and physical processes in a diverse range of astrophysical settings. The EU/FP7-Cooperation Space framework project, `Exploring the X-ray transient and variable sky' (EXTraS), aims to exploit these XMM-Newton resources to explore, as fully as possible, the range of X-ray variability present and provide the results to the community through a public database. Here we outline one of the project's core aims, i.e. identifying and characterising long-term (days to years) variability. The 3XMM-DR4 catalogue contains ˜67000 sources with multiple detections. 3XMM, in conjunction with the XSS, which has now covered almost 70% of the sky, often with multiple slews, offers excellent scope for identifying new variable objects by tracking their flux between XMM-Newton observations. We discuss the plans for the EXTraS long-term variability catalogue and highlight some examples of the detection of long-term variability in 3XMM-DR4/XSS data.
NASA Technical Reports Server (NTRS)
1991-01-01
Diatek Corporation, San Diego, CA and the Jet Propulsion Lab developed the Diatek Model 7000 aural thermometer which weighs only eight ounces, and measures temperature in less than two seconds using infrared astronomy technology to measure the amount of infrared energy emitted by the eardrum (the same way temperature of stars and planets is measured). This method avoids contact with mucous membranes, virtually eliminating the possibility of cross infection, and permits temperature measurement of newborn, critically ill, or incapacitated patients. Diatek Corporation was purchased by Welch Allyn Inc. The Diatek Model 7000 is now marketed as SureTemp.
NASA Technical Reports Server (NTRS)
Gillett, Frederick; Houck, James; Bally, John; Becklin, Eric; Brown, Robert Hamilton; Draine, Bruce; Frogel, Jay; Gatley, Ian; Gehrz, Robert; Hildebrand, Roger
1991-01-01
The decade of 1990's presents an opportunity to address fundamental astrophysical issues through observations at IR wavelengths made possible by technological and scientific advances during the last decade. The major elements of recommended program are: the Space Infrared Telescope Facility (SIRTF), the Stratospheric Observatory For Infrared Astronomy (SOFIA) and the IR Optimized 8-m Telescope (IRO), a detector and instrumentation program, the SubMilliMeter Mission (SMMM), the 2 Microns All Sky Survey (2MASS), a sound infrastructure, and technology development programs. Also presented are: perspective, science opportunities, technical overview, project recommendations, future directions, and infrastructure.
NASA Technical Reports Server (NTRS)
1987-01-01
United Scanning Technologies, Inc.'s Infrared thermography is a relatively new noncontact, nondestructive inspection and testing tool which makes temperatures visible to the human eye. Infrared scanning devices produce images that show, by color or black and white shading differences, heat losses through damaged or inadequately insulated walls or roofs. The MISS Aeroscan services are designed to take the guesswork out of industrial roof maintenance and provide companies big savings by identifying the location of moisture damage from roof leaks, effectively targeting maintenance attention.
Evolution in random fitness landscapes: the infinite sites model
NASA Astrophysics Data System (ADS)
Park, Su-Chan; Krug, Joachim
2008-04-01
We consider the evolution of an asexually reproducing population in an uncorrelated random fitness landscape in the limit of infinite genome size, which implies that each mutation generates a new fitness value drawn from a probability distribution g(w). This is the finite population version of Kingman's house of cards model (Kingman 1978 J. Appl. Probab. 15 1). In contrast to Kingman's work, the focus here is on unbounded distributions g(w) which lead to an indefinite growth of the population fitness. The model is solved analytically in the limit of infinite population size N \\to \\infty and simulated numerically for finite N. When the genome-wide mutation probability U is small, the long-time behavior of the model reduces to a point process of fixation events, which is referred to as a diluted record process (DRP). The DRP is similar to the standard record process except that a new record candidate (a number that exceeds all previous entries in the sequence) is accepted only with a certain probability that depends on the values of the current record and the candidate. We develop a systematic analytic approximation scheme for the DRP. At finite U the fitness frequency distribution of the population decomposes into a stationary part due to mutations and a traveling wave component due to selection, which is shown to imply a reduction of the mean fitness by a factor of 1-U compared to the U \\to 0 limit.
Probabilistic context-free grammars estimated from infinite distributions.
Corazza, Anna; Satta, Giorgio
2007-08-01
In this paper, we consider probabilistic context-free grammars, a class of generative devices that has been successfully exploited in several applications of syntactic pattern matching, especially in statistical natural language parsing. We investigate the problem of training probabilistic context-free grammars on the basis of distributions defined over an infinite set of trees or an infinite set of sentences by minimizing the cross-entropy. This problem has applications in cases of context-free approximation of distributions generated by more expressive statistical models. We show several interesting theoretical properties of probabilistic context-free grammars that are estimated in this way, including the previously unknown equivalence between the grammar cross-entropy with the input distribution and the so-called derivational entropy of the grammar itself. We discuss important consequences of these results involving the standard application of the maximum-likelihood estimator on finite tree and sentence samples, as well as other finite-state models such as Hidden Markov Models and probabilistic finite automata. PMID:17568142
Relativistic regular approximations revisited: An infinite-order relativistic approximation
Dyall, K.G.; van Lenthe, E.
1999-07-01
The concept of the regular approximation is presented as the neglect of the energy dependence of the exact Foldy{endash}Wouthuysen transformation of the Dirac Hamiltonian. Expansion of the normalization terms leads immediately to the zeroth-order regular approximation (ZORA) and first-order regular approximation (FORA) Hamiltonians as the zeroth- and first-order terms of the expansion. The expansion may be taken to infinite order by using an un-normalized Foldy{endash}Wouthuysen transformation, which results in the ZORA Hamiltonian and a nonunit metric. This infinite-order regular approximation, IORA, has eigenvalues which differ from the Dirac eigenvalues by order E{sup 3}/c{sup 4} for a hydrogen-like system, which is a considerable improvement over the ZORA eigenvalues, and similar to the nonvariational FORA energies. A further perturbation analysis yields a third-order correction to the IORA energies, TIORA. Results are presented for several systems including the neutral U atom. The IORA eigenvalues for all but the 1s spinor of the neutral system are superior even to the scaled ZORA energies, which are exact for the hydrogenic system. The third-order correction reduces the IORA error for the inner orbitals to a very small fraction of the Dirac eigenvalue. {copyright} {ital 1999 American Institute of Physics.}
Infinite Factorial Unbounded-State Hidden Markov Model.
Valera, Isabel; Ruiz, Francisco J R; Perez-Cruz, Fernando
2016-09-01
There are many scenarios in artificial intelligence, signal processing or medicine, in which a temporal sequence consists of several unknown overlapping independent causes, and we are interested in accurately recovering those canonical causes. Factorial hidden Markov models (FHMMs) present the versatility to provide a good fit to these scenarios. However, in some scenarios, the number of causes or the number of states of the FHMM cannot be known or limited a priori. In this paper, we propose an infinite factorial unbounded-state hidden Markov model (IFUHMM), in which the number of parallel hidden Markovmodels (HMMs) and states in each HMM are potentially unbounded. We rely on a Bayesian nonparametric (BNP) prior over integer-valued matrices, in which the columns represent the Markov chains, the rows the time indexes, and the integers the state for each chain and time instant. First, we extend the existent infinite factorial binary-state HMM to allow for any number of states. Then, we modify this model to allow for an unbounded number of states and derive an MCMC-based inference algorithm that properly deals with the trade-off between the unbounded number of states and chains. We illustrate the performance of our proposed models in the power disaggregation problem. PMID:26571511
Masses of atomic nuclei in the infinite nuclear matter model
Satpathy, L.; Nayak, R.C.
1988-07-01
We present mass excesses of 3481 nuclei in the range 18less than or equal toAless than or equal to267 using the infinite nuclear matter model based on the Hugenholtz-Van Hove theorem. In this model the ground-state energy of a nucleus of asymmetry ..beta.. is considered equivalent to the energy of a perfect sphere made up of the infinite nuclear matter of the same asymmetry plus the residual energy due to shell effects, deformation, etc., called the local energy eta. In this model there are two kinds of parameters: global and local. The five global parameters characterizing the properties of the above sphere are determined by fitting the mass of all nuclei (756) in the recent mass table of Wapstra et al. having error bar less than 30 keV. The local parameters are determined for 25 regions each spanning 8 or 10 A values. The total number of parameters including the five global ones is 238. The root-mean-square deviation for the calculated masses from experiment is 397 keV for the 1572 nuclei used in the least-squares fit. copyright 1988 Academic Press, Inc.
NASA Technical Reports Server (NTRS)
Bensoussan, A.; Delfour, M. C.; Mitter, S. K.
1976-01-01
Available published results are surveyed for a special class of infinite-dimensional control systems whose evolution is characterized by a semigroup of operators of class C subscript zero. Emphasis is placed on an approach that clarifies the system-theoretic relationship among controllability, stabilizability, stability, and the existence of a solution to an associated operator equation of the Riccati type. Formulation of the optimal control problem is reviewed along with the asymptotic behavior of solutions to a general system of equations and several theorems concerning L2 stability. Examples are briefly discussed which involve second-order parabolic systems, first-order hyperbolic systems, and distributed boundary control.
Pupil phase apodization for achromatic imaging of extra- solar planets
NASA Astrophysics Data System (ADS)
Yang, Weidong
2004-09-01
Direct imaging of extra-solar planets in the visible and infrared region has generated great interest among scientists and the general public as well. However, this is a challenging problem. Difficulties of detecting a planet (faint source) are caused, mostly, by two factors: sidelobes caused by starlight diffraction from the edge of the pupil and the randomly scattered starlight caused by the phase errors from the imperfections in the optical system. While the latter difficulty can be corrected by high density active deformable mirrors with advanced phase sensing and control technology, the optimized strategy for suppressing the diffraction sidelobes is still an open question. In this thesis, I present a new approach to the sidelobe reduction problem: pupil phase apodization. It is based on a discovery that an anti-symmetric spatial phase modulation pattern imposed over a pupil or a relay plane causes diffracted starlight suppression sufficient for imaging of extra-solar planets. Numerical simulations with specific square pupil (side D) phase functions, such as f(x,y)=a[ln ((1+3)+ 2x/D)/((1+3)-2x/D) . ((1+3)+2y/D)/((1+3)-2y/D)] demonstrate annulling in at least one quadrant of the diffraction plane to the contrast level of better than 10-12 with an inner working angle down to 3.5λ/D (with a = 3 and 3 = 10-3). Furthermore, our computer experiments show that phase apodization remains effective throughout a broad spectrum (60% of the central wavelength) covering the entire visible light range. In addition to the specific phase functions that can yield deep sidelobe reduction on one quadrant; we also found that a modified Gerchberg-Saxton algorithm can help to find small sized (101 x 101 element) discrete phase functions if regional sidelobe reduction is desired. Our simulation shows that a 101 x 101 segmented but gapless active mirror can also generate a dark region with Inner Working Distance about 2.8λ/D in one quadrant. Phase-only modulation has the additional
ERIC Educational Resources Information Center
Schaefers, John
2006-01-01
An infrared (IR) thermometer lab offers the opportunity to give science students a chance to measure surface temperatures, utilizing off-the-shelf technology. Potential areas of study include astronomy (exoplanets), electromagnetic spectrum, chemistry, evaporation rates, anatomy, crystal formation, and water or liquids. This article presents one…
NASA Technical Reports Server (NTRS)
Karr, G. R.; Hendricks, J. B.
1985-01-01
The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.
NASA Astrophysics Data System (ADS)
Lopez, B. A.
1984-11-01
Infrared spectroscopic analysis is reviewed. Applications to chemical analysis of preimpregnated carbon fiber materials, including polystyrene spectra, epoxy resin analysis, mineral loads analysis, determination of epoxy groups and identification of spurious organic materials are discussed. The advantages of the method for quality control are pointed out.
Detecting extra-solar planets with the Japanese 3.5 m SPICA space telescope
NASA Astrophysics Data System (ADS)
Abe, Lyu; Enya, Keigo; Tanaka, Shinichiro; Nakagawa, Takao; Kataza, Hirokazu; Tamura, Motohide; Guyon, Olivier
2007-04-01
We present the 3.5 m SPace Infrared telescope for Cosmology and Astrophysics (SPICA) space telescope, the launch of which is schedule around year 2015 by the Japanese HII-A rocket, and specifically discuss its use in the context of direct observation of extra-solar planets. This actively cooled (4.5 K), single aperture telescope will operate in the mid and far infrared spectral regions, and up to submillimetric wavelengths (200 μm). The lowest spectral region (5 to 20 μm), where the spatial resolution is the most favorable, will be dedicated to high contrast imaging with coronagraphy. This article describes the SPICA coronagraph project in terms of science, as well as our efforts to study a suitable instrumental concept, compatible with the constraints of the telescope architecture. To cite this article: L. Abe et al., C. R. Physique 8 (2007).
Extra-glycaemic properties of empagliflozin.
Solini, Anna
2016-03-01
Type 2 diabetes is a complex and multifaceted disease requiring an individualized approach. A special attention, in treating the patients, should be devoted to the presence of comorbidities like overweight or obesity and arterial hypertension. Among the available anti-hyperglycaemic agents, several are associated with side effects like hypoglycaemia and weight gain. An increasing interest is reported in sodium-glucose co-transporter-2 inhibitors, a relatively novel class of glucose-lowering drugs that act independently of insulin, provide benefits beyond glucose-lowering actions and show a better tolerability compared with traditional medications for type 2 diabetes. This review tries to offer a balanced view on the main extra-glycaemic effects of empagliflozin, also mentioning clinical data obtained with other sodium-glucose co-transporter-2 inhibitors; the role of the proximal tubule in the pathophysiology of diabetic nephropathy and the potential nehroprotection exerted by this compound are also briefly discussed. PMID:25994513
Lepton flavor violation in extra dimension models
Chang, W.-F.; Ng, John N.
2005-03-01
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some five-dimensional (5D) models which are related to neutrino mass generation or address the fermion masses hierarchy problem. We study the signatures in low energy experiments that can discriminate the different models. The focus is on muon-electron conversion in nuclei {mu}{yields}e{gamma} and {mu}{yields}3e processes and their {tau} counterparts. Their links with the active neutrino mass matrix are investigated. We show that in the models we discussed the branching ratio of {mu}{yields}e{gamma} like rare process is much smaller than the ones of {mu}{yields}3e like processes. This is in sharp contrast to most of the traditional wisdom based on four-dimensional (4D) gauge models. Moreover, some rare tau decays are more promising than the rare muon decays.
Dark Energy as Extra-Dimensional Gravity
NASA Astrophysics Data System (ADS)
Burgess, C. P.
The nature of dark energy, which presently dominates the universal energy budget, remains a complete mystery. Models in which it is currently evolving tend to be overly sensitive to initial conditions, and necessarily involve a very light degree of freedom which is very difficult to obtain from realistic microscopic physics. This essay describes recent progress in understanding how the dark energy can arise as a residue of extra-dimensional gravitation, leading to new insights into how dark-energy cosmology might work. This picture produces dark energy dynamics within which couplings slowly run (or: 'walk') over cosmological times. It also has several unusual experimental predictions, including measurable modifications to Newton's Law on sub-millimeter scales and dramatic implications at next-generation collider experiments.
Extra tactile stimulation of the premature infant.
Kramer, M; Chamorro, I; Green, D; Knudtson, F
1975-01-01
To ascertain whether touch, in the form of extra tactile stimulation, would result in more rapid physical and social development and a greater degree of social development of the premature infant, 48 minutes of extra tactile stimulation, defines as a gentle, nonrhythmic stroking of the greatest possible area of skin surface of the infant's body by the nurse's hand, was given to eight experimental group premature infants daily for a minimum of two weeks while they were confined to an isolette. Six infants formed a control group. Regain of birth weight was used to assess physical development. Scores on the applicable portions of the Gesell Development Schedule and Bayley Scales of Infant Development and plasma cortisol levels were used to measure rate and degree of social development. Data were analyzed in terms of the total group and for pairs of infants matched for gestational age, birth weight, and Apgar score. No significant difference was found between control and experimental groups in rate of physical development as measured by regain of birth weight. Analysis of the relationship between weight gain and gestational age, sex, and Apgar scores indicated that none was a substantial indicator of the rate at which infants gained weight while in the hospital. There was no significant difference in the degree of social development between experimental and control infants, but, as hypothesized, there was significant difference in rate of social development. Plasma cortisol levels as an indication of the infant's adrenocorticol development as evidenced by his ability to respond to stressful situations, and hence indirectly his social development, revealed no significant difference between the two groups. PMID:1041616
Infrared limit of Horava's gravity with the global Hamiltonian constraint
Kobakhidze, Archil
2010-09-15
We show that Horava's theory of gravitation with the global Hamiltonian constraint does not reproduce general relativity in the infrared domain. There is one extra propagating degree of freedom, besides those two associated with the massless graviton, which does not decouple.
Chemical impurity produces extra compound eyes and heads in crickets
Walton, B.T.
1981-04-03
A chemical impurity isolated from commercially purchased acridine causes cricket embryos to develop extra compound eyes, branched antennae, extra antennae, and extra heads. Purified acridine does not produce similar duplications of cricket heads or head structures nor do the substituted acridines proflavine, acriflavine, or acridine orange. A dose-response relation exists such that the number and severity of abnormalities increase with increasing concentration of the teratogen.
Dynamics of Bubbles Rising in Finite and Infinite Media
C.C. Maneri; P.F. Vassallo
2000-10-27
The dynamic behavior of single bubbles rising in quiescent liquid Suva (R134a) in a duct has been examined through the use of a high speed video system. Size, shape and velocity measurements obtained with the video system reveal a wide variety of characteristics for the bubbles as they rise in both finite and infinite media. This data, coupled with previously published data for other working fluids, has been used to assess and extend a rise velocity model given by Fan and Tsuchiya. As a result of this assessment, a new rise velocity model has been developed which maintains the physically consistent characteristics of the surface tension in the distorted bubbly regime. In addition, the model is unique in that it covers the entire range of bubble sizes contained in the spherical, distorted and planar slug regimes.
Doubly infinite separation of quantum information and communication
NASA Astrophysics Data System (ADS)
Liu, Zi-Wen; Perry, Christopher; Zhu, Yechao; Koh, Dax Enshan; Aaronson, Scott
2016-01-01
We prove the existence of (one-way) communication tasks with a subconstant versus superconstant asymptotic gap, which we call "doubly infinite," between their quantum information and communication complexities. We do so by studying the exclusion game [C. Perry et al., Phys. Rev. Lett. 115, 030504 (2015), 10.1103/PhysRevLett.115.030504] for which there exist instances where the quantum information complexity tends to zero as the size of the input n increases. By showing that the quantum communication complexity of these games scales at least logarithmically in n , we obtain our result. We further show that the established lower bounds and gaps still hold even if we allow a small probability of error. However in this case, the n -qubit quantum message of the zero-error strategy can be compressed polynomially.
Phases of the infinite U Hubbard model on square lattices.
Liu, Li; Yao, Hong; Berg, Erez; White, Steven R; Kivelson, Steven A
2012-03-23
We apply the density matrix renormalization group to study the phase diagram of the infinite U Hubbard model on 2- to 6-leg ladders. Where the results are largely insensitive to the ladder width, we consider the results representative of the 2D square lattice. We find a fully polarized ferromagnetic Fermi liquid phase when n, the density of electrons per site, is in the range 1>n≳0.800. For n=3/4 we find an unexpected insulating checkerboard phase with coexisting bond-density order with 4 sites per unit cell and block-spin antiferromagnetic order with 8 sites per unit cell. For 3/4>n, all ladders with width >2 have unpolarized ground states. PMID:22540606
Exploring percolative landscapes: Infinite cascades of geometric phase transitions
NASA Astrophysics Data System (ADS)
Timonin, P. N.; Chitov, Gennady Y.
2016-01-01
The evolution of many kinetic processes in 1+1 (space-time) dimensions results in 2 D directed percolative landscapes. The active phases of these models possess numerous hidden geometric orders characterized by various types of large-scale and/or coarse-grained percolative backbones that we define. For the patterns originated in the classical directed percolation (DP) and contact process we show from the Monte Carlo simulation data that these percolative backbones emerge at specific critical points as a result of continuous phase transitions. These geometric transitions belong to the DP universality class and their nonlocal order parameters are the capacities of corresponding backbones. The multitude of conceivable percolative backbones implies the existence of infinite cascades of such geometric transitions in the kinetic processes considered. We present simple arguments to support the conjecture that such cascades of transitions are a generic feature of percolation as well as of many other transitions with nonlocal order parameters.
Infinite phased array of microstrip dipoles in two layers
NASA Astrophysics Data System (ADS)
Castaneda, Jesus A.
1989-01-01
A method has been devised for the analysis of the infinite printed strip dipole array in a two layer microstrip substrate structure. The complete dynamic Green's function appropriate to the two-layer substrate-superstrate structure was used in the formulation of the method of moments solution. In this way all the substrate effects, including the surface wave related phenomena, have been included in the development and solution. The solution provides a means by which the most important performance characteristics of the finite-but-large phase-scanned microstrip array can be studied. Attention has been focused on the characterization of the active input impedance as a function of the equivalent scan angle.
A General No-Cloning Theorem for an infinite Multiverse
NASA Astrophysics Data System (ADS)
Gauthier, Yvon
2013-10-01
In this paper, I formulate a general no-cloning theorem which covers the quantum-mechanical and the theoretical quantum information cases as well as the cosmological multiverse theory. However, the main argument is topological and does not involve the peculiar copier devices of the quantum-mechanical and information-theoretic approaches to the no-cloning thesis. It is shown that a combinatorial set-theoretic treatment of the mathematical and physical spacetime continuum in cosmological or quantum-mechanical terms forbids an infinite (countable or uncountable) number of exact copies of finite elements (states) in the uncountable multiverse cosmology. The historical background draws on ideas from Weyl to Conway and Kochen on the free will theorem in quantum mechanics.
On q-deformed infinite-dimensional n-algebra
NASA Astrophysics Data System (ADS)
Ding, Lu; Jia, Xiao-Yu; Wu, Ke; Yan, Zhao-Wen; Zhao, Wei-Zhong
2016-03-01
The q-deformation of the infinite-dimensional n-algebras is investigated. Based on the structure of the q-deformed Virasoro-Witt algebra, we derive a nontrivial q-deformed Virasoro-Witt n-algebra which is nothing but a sh-n-Lie algebra. Furthermore in terms of the pseud-differential operators, we construct the (co)sine n-algebra and the q-deformed S Diff (T2)n-algebra. We find that they are the sh-n-Lie algebras for the n even case. In terms of the magnetic translation operators, an explicit physical realization of the (co)sine n-algebra is given.
Second quantisation for skew convolution products of infinitely divisible measures
NASA Astrophysics Data System (ADS)
Applebaum, David; van Neerven, Jan
2015-03-01
Suppose λ1 and λ2 are infinitely divisible Radon measures on real Banach spaces E1 and E2, respectively and let T : E1 → E2 be a Borel measurable mapping so that T(λ1) * ρ = λ2 for some Radon probability measure ρ on E2. Extending previous results for the Gaussian and the Poissonian case, we study the problem of representing the "transition operator" PT : Lp(E2, λ2) → Lp(E1, λ1) given by $PTf(x) = ∫ E{2}f(T(x) + y)dρ (y)$ as the second quantisation of a contraction operator acting between suitably chosen "reproducing kernel Hilbert spaces" associated with λ1 and λ2.
Multipoint inverse design of an infinite cascade of airfoils
NASA Astrophysics Data System (ADS)
Selig, M. S.
1994-04-01
This paper describes a method for the design of an infinite cascade in incompressible flow. The method is based on conformal mapping and does not allow for multipoint design. The cascade blade is to determined is divided into a number of segments. Over each segment, the velocity distribution is prescribed together with an inlet or outlet flow angle at which this velocity distributions is to be achieved. In this way multipoint design requirements can be met. It is necessary to satisfy several conditions that arise to guarantee compatibility with the inlet and outlet flow as well as closure of the cascade blade. Satisfaction of these conditions does not necessarily result in a cascade with all of the desired characteristucs. For example, the cascade blades may be bulbous or crossed. Through Newtonian iteration, however, the desired characteristics may be prescribed directly. Four examples will be illustrated to demonstrate the capability of the method.
Variational optimization with infinite projected entangled-pair states
NASA Astrophysics Data System (ADS)
Corboz, Philippe
2016-07-01
We present a scheme to perform an iterative variational optimization with infinite projected entangled-pair states, a tensor network ansatz for a two-dimensional wave function in the thermodynamic limit, to compute the ground state of a local Hamiltonian. The method is based on a systematic summation of Hamiltonian contributions using the corner-transfer-matrix method. Benchmark results for challenging problems are presented, including the two-dimensional Heisenberg model, the Shastry-Sutherland model, and the t -J model, which show that the variational scheme yields considerably more accurate results than the previously best imaginary-time evolution algorithm, with a similar computational cost and with a faster convergence towards the ground state.
Recurrent kernel machines: computing with infinite echo state networks.
Hermans, Michiel; Schrauwen, Benjamin
2012-01-01
Echo state networks (ESNs) are large, random recurrent neural networks with a single trained linear readout layer. Despite the untrained nature of the recurrent weights, they are capable of performing universal computations on temporal input data, which makes them interesting for both theoretical research and practical applications. The key to their success lies in the fact that the network computes a broad set of nonlinear, spatiotemporal mappings of the input data, on which linear regression or classification can easily be performed. One could consider the reservoir as a spatiotemporal kernel, in which the mapping to a high-dimensional space is computed explicitly. In this letter, we build on this idea and extend the concept of ESNs to infinite-sized recurrent neural networks, which can be considered recursive kernels that subsequently can be used to create recursive support vector machines. We present the theoretical framework, provide several practical examples of recursive kernels, and apply them to typical temporal tasks. PMID:21851278
Unstable infinite nuclear matter in stochastic mean field approach
Colonna, M.; Chomaz, P. Laboratorio Nazionale del Sud, Viale Andrea Doria, Catania )
1994-04-01
In this article, we consider a semiclassical stochastic mean-field approach. In the case of unstable infinite nuclear matter, we calculate the characteristic time of the exponential growing of fluctuations and the diffusion coefficients associated to the unstable modes, in the framework of the Boltzmann-Langevin theory. These two quantities are essential to describe the dynamics of fluctuations and instabilities since, in the unstable regions, the evolution of the system will be dominated by the amplification of fluctuations. In order to make realistic 3D calculations feasible, we suggest to replace the complicated Boltzmann-Langevin theory by a simpler stochastic mean-field approach corresponding to a standard Boltzmann evolution, complemented by a simple noise chosen to reproduce the dynamics of the most unstable modes. Finally we explain how to approximately implement this method by simply tuning the noise associated to the use of a finite number of test particles in Boltzman-like calculations.
The gravitational field of an infinite flat slab
NASA Astrophysics Data System (ADS)
Fulling, S. A.; Bouas, J. D.; Carter, H. B.
2015-08-01
We study Einstein's equations with a localized plane-symmetric source, with close attention to gauge freedom/fixing and to listing all physically distinct solutions. In the vacuum regions there are only two qualitatively different solutions, one curved and one flat; in addition, on each of the two sides there is a free parameter describing how the slab is embedded into the vacuum region. Surprisingly, for a generic slab source the solution must be curved on one side and flat on the other. We treat infinitely thin slabs in full detail and indicate how thick slabs can increase the variety of external geometry pairs. Positive energy density seems to force external geometries with curvature singularities at some distance from the slab; we speculate that such singularities occur in regions where the solution cannot be physically relevant anyway.
Exploring percolative landscapes: Infinite cascades of geometric phase transitions.
Timonin, P N; Chitov, Gennady Y
2016-01-01
The evolution of many kinetic processes in 1+1 (space-time) dimensions results in 2D directed percolative landscapes. The active phases of these models possess numerous hidden geometric orders characterized by various types of large-scale and/or coarse-grained percolative backbones that we define. For the patterns originated in the classical directed percolation (DP) and contact process we show from the Monte Carlo simulation data that these percolative backbones emerge at specific critical points as a result of continuous phase transitions. These geometric transitions belong to the DP universality class and their nonlocal order parameters are the capacities of corresponding backbones. The multitude of conceivable percolative backbones implies the existence of infinite cascades of such geometric transitions in the kinetic processes considered. We present simple arguments to support the conjecture that such cascades of transitions are a generic feature of percolation as well as of many other transitions with nonlocal order parameters. PMID:26871019
Persistence in nonautonomous predator-prey systems with infinite delays
NASA Astrophysics Data System (ADS)
Teng, Zhidong; Rehim, Mehbuba
2006-12-01
This paper studies the general nonautonomous predator-prey Lotka-Volterra systems with infinite delays. The sufficient and necessary conditions of integrable form on the permanence and persistence of species are established. A very interesting and important property of two-species predator-prey systems is discovered, that is, the permanence of species and the existence of a persistent solution are each other equivalent. Particularly, for the periodic system with delays, applying these results, the sufficient and necessary conditions on the permanence and the existence of positive periodic solutions are obtained. Some well-known results on the nondelayed periodic predator-prey Lotka-Volterra systems are strongly improved and extended to the delayed case.
Infinite-noise criticality: Nonequilibrium phase transitions in fluctuating environments
NASA Astrophysics Data System (ADS)
Vojta, Thomas; Hoyos, Jose
We study the effects of time-varying environmental noise on nonequilibrium phase transitions in spreading and growth processes. Using the examples of the logistic evolution equation as well as the contact process, we show that such temporal disorder gives rise to a distinct type of critical points at which the effective noise amplitude diverges on long time scales. This leads to enormous density fluctuations characterized by an infinitely broad probability distribution at criticality. We develop a real-time renormalization-group theory that provides a general framework for the effects of temporal disorder on nonequilibrium processes. We also discuss how general this exotic critical behavior is, we illustrate the results by computer simulations, and we touch upon experimental applications of our theory. Supported by the NSF under Grant No. DMR-1205803, by Simons Foundation, by FAPESP under Grant No. 2013/09850-7, and by CNPq under Grant Nos. 590093/2011-8 and 305261/2012-6.
Science with the EXTraS Project: Exploring the X-Ray Transient and Variable Sky
NASA Astrophysics Data System (ADS)
De Luca, A.; Salvaterra, R.; Tiengo, A.; D'Agostino, D.; Watson, M. G.; Haberl, F.; Wilms, J.
The EXTraS project ("Exploring the X-ray Transient and variable Sky") will characterise the temporal behaviour of the largest ever sample of objects in the soft X-ray range (0.1-12 keV) with a complex, systematic and consistent analysis of all data collected by the European Photon Imaging Camera (EPIC) instrument onboard the ESA XMM-Newton X-ray observatory since its launch. We will search for, and characterize variability (both periodic and aperiodic) in hundreds of thousands of sources spanning more than nine orders of magnitude in time scale and six orders of magnitude in flux. We will also search for fast transients, missed by standard image analysis. Our analysis will be completed by multiwavelength characterization of new discoveries and phenomenological classification of variable sources. All results and products will be made available to the community in a public archive, serving as a reference for a broad range of astrophysical investigations.
Exact solutions of a modified fractional diffusion equation in the finite and semi-infinite domains
NASA Astrophysics Data System (ADS)
Guo, Gang; Li, Kun; Wang, Yuhui
2015-01-01
We investigate the solutions of a modified fractional diffusion equation which has a secondary fractional time derivative acting on a diffusion operator. We obtain analytical solutions for the modified equation in the finite and semi-infinite domains subject to absorbing boundary conditions. Most of the results have been derived by using the Laplace transform, the Fourier Cosine transform, the Mellin transform and the properties of Fox H function. We show that the semi-infinite solution can be expressed using an infinite series of Fox H functions similar to the infinite case, while the finite solution requires double infinite series including both Fox H functions and trigonometric functions instead of one infinite series. The characteristic crossover between more and less anomalous behaviour as well as the effect of absorbing boundary conditions are clearly demonstrated according to the analytical solutions.
Infinite-range Heisenberg model and high-temperature superconductivity
NASA Astrophysics Data System (ADS)
Tahir-Kheli, Jamil; Goddard, William A., III
1993-11-01
A strongly coupled variational wave function, the doublet spin-projected Néel state (DSPN), is proposed for oxygen holes in three-band models of high-temperature superconductors. This wave function has the three-spin system of the oxygen hole plus the two neighboring copper atoms coupled in a spin-1/2 doublet. The copper spins in the neighborhood of a hole are in an eigenstate of the infinite-range Heisenberg antiferromagnet (SPN state). The doublet three-spin magnetic polaron or hopping polaron (HP) is stabilized by the hopping terms tσ and tτ, rather than by the copper-oxygen antiferromagnetic coupling Jpd. Although, the HP has a large projection onto the Emery (Dg) polaron, a non-negligible amount of doublet-u (Du) character is required for optimal hopping stabilization. This is due to Jdd, the copper-copper antiferromagnetic coupling. For the copper spins near an oxygen hole, the copper-copper antiferromagnetic coupling can be considered to be almost infinite ranged, since the copper-spin-correlation length in the superconducting phase (0.06-0.25 holes per in-plane copper) is approximately equal to the mean separation of the holes (between 2 and 4 lattice spacings). The general DSPN wave function is constructed for the motion of a single quasiparticle in an antiferromagnetic background. The SPN state allows simple calculations of various couplings of the oxygen hole with the copper spins. The energy minimum is found at symmetry (π/2,π/2) and the bandwidth scales with Jdd. These results are in agreement with exact computations on a lattice. The coupling of the quasiparticles leads to an attraction of holes and its magnitude is estimated.
Infinite networks and variation of conductance functions in discrete Laplacians
NASA Astrophysics Data System (ADS)
Jorgensen, Palle; Tian, Feng
2015-04-01
For a given infinite connected graph G = (V, E) and an arbitrary but fixed conductance function c, we study an associated graph Laplacian Δc; it is a generalized difference operator where the differences are measured across the edges E in G; and the conductance function c represents the corresponding coefficients. The graph Laplacian (a key tool in the study of infinite networks) acts in an energy Hilbert space ℋE computed from c. Using a certain Parseval frame, we study the spectral theoretic properties of graph Laplacians. In fact, for fixed c, there are two versions of the graph Laplacian, one defined naturally in the l2 space of V and the other in ℋE. The first is automatically selfadjoint, but the second involves a Krein extension. We prove that, as sets, the two spectra are the same, aside from the point 0. The point zero may be in the spectrum of the second, but not the first. We further study the fine structure of the respective spectra as the conductance function varies, showing now how the spectrum changes subject to variations in the function c. Specifically, we study an order on the spectra of the family of operators Δc, and we compare it to the ordering of pairs of conductance functions. We show how point-wise estimates for two conductance functions translate into spectral comparisons for the two corresponding graph Laplacians, involving a certain similarity: We prove that point-wise ordering of two conductance functions c on E induces a certain similarity of the corresponding (Krein extensions computed from the) two graph Laplacians Δc. The spectra are typically continuous, and precise notions of fine-structure of spectrum must be defined in terms of equivalence classes of positive Borel measures (on the real line). Our detailed comparison of spectra is analyzed this way.
Levin, Robert E.; English, George J.
1986-08-05
An infrared floodlight assembly designed particularly for security purposes and including a heat-conducting housing, a lens secured to the housing to provide a closure therefor, and a floodlight located within (and surrounded by) the housing. The floodlight combines the use of a tungsten halogen light source and dichroic hot and cold mirrors for directing substantially only infrared radiation toward the assembly's forward lens. Visible radiation is absorbed by the housing's interior wall(s) and, optionally, by a filter located between the floodlight and lens. An optional means may be used within the floodlight to reflect all forward radiation back toward the paraboloidal hot mirror or, alternatively, to reflect only visible radiation in this direction. The dichroic hot and cold mirrors preferably each comprise a glass substrate having multiple layers of titanium dioxide and silicon dioxide thereon.
Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong
2011-12-06
Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.
NASA Technical Reports Server (NTRS)
Bohren, Craig F.; Nevitt, Timothy J.; Singham, Shermila Brito
1989-01-01
All particles in the atmosphere are not spherical. Moreover, the scattering properties of randomly oriented nonspherical particles are not equivalent to those of spherical particles no matter how the term equivalent is defined. This is especially true for scattering in the backward direction and at the infrared wavelengths at which some atmospheric particles have strong absorption bands. Thus calculations based on Mie theory of infrared backscattering by dry or insoluble atmospheric particles are suspect. To support this assertion, it was noted that peaks in laboratory-measured infrared backscattering spectra show appreciable shifts compared with those calculated using Mie theory. One example is ammonium sulfate. Some success was had in modeling backscattering spectra of ammonium sulfate particles using a simple statistical theory called the continuous distribution of ellipsoids (CDE) theory. In this theory, the scattering properties of an ensemble are calculated. Recently a modified version of this theory was applied to measured spectra of scattering by kaolin particles. The particles were platelike, so the probability distribution of ellipsoidal shapes was chosen to reflect this. As with ammonium sulfate, the wavelength of measured peak backscattering is shifted longward of that predicted by Mie theory.
On ``nothing'' as an infinitely negatively curved spacetime
NASA Astrophysics Data System (ADS)
Brown, Adam R.; Dahlen, Alex
2012-05-01
Nothing—the absence of spacetime—can be either an endpoint of tunneling, as in the bubble of nothing, or a starting point for tunneling, as in the quantum creation of a universe. We argue that these two tunnelings can be treated within a unified framework, and that, in both cases, nothing should be thought of as the limit of anti-de Sitter space in which the curvature length approaches zero. To study nothing, we study decays in models with perturbatively stabilized extra dimensions, which admit not just bubbles of nothing—topology-changing transitions in which the extra dimensions pinch off and a hole forms in spacetime—but also a whole family of topology-preserving transitions that nonetheless smoothly hollow out and approach the bubble of nothing in one limit. The bubble solutions that are close to this limit, bubbles of next-to-nothing, give us a controlled setting in which to understand nothing. Armed with this understanding, we are able to embed proposed mechanisms for the reverse process, tunneling from nothing to something, within the relatively secure foundation of the Coleman-De Luccia formalism and show that the Hawking-Turok instanton does not mediate the quantum creation of a universe.
The evolution of comets and the detectability of Extra-Solar Oort Clouds
Stern, S.A.
1989-01-01
According the standard theory, comets are natural products of solar system formation, ejected to the Oort Cloud by gravitational scattering events during the epoch of giant planet formation. Stored far from the Sun for billions of years, comets almost certainly contain a record of the events which occurred during (and perhaps even before) the epoch of planetary formation. Two themes are examined of the evolutionary processes that affect comets in the Oort Cloud, and a search for evidence of Extra-Solar Oort Clouds (ESOCs). With regard to cometary evolution in the Oort Cloud, it was found that luminous O stars and supernovae have heated the surface layers of all comets on numerous occasions to 20 to 30 K and perhaps once to 50 K. Interstellar medium (ISM) interactions blow small grains out of the Oort Clouds, and erode the upper few hundred g/cu cm of material from cometary surfaces. The findings presented contradict the standard view that comets do not undergo physical change in the Oort Cloud. A logical consequence of the intimate connection between the Oort Cloud and our planetary system is that the detection of comet clouds around other stars would strongly indicate the sites of extant extra-solar planetary systems. A search was conducted for infrared IR emission from debris in ESOCs. After examining 17 stars using the Infrared Astronomical Satellite data base, only upper limits on ESOC emission could be set.
23 CFR 635.120 - Changes and extra work.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 23 Highways 1 2013-04-01 2013-04-01 false Changes and extra work. 635.120 Section 635.120 Highways... CONSTRUCTION AND MAINTENANCE Contract Procedures § 635.120 Changes and extra work. (a) Following authorization... work shall have formal approval by the Division Administrator in advance of their effective...