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Sample records for accurate relativistic energy-consistent

  1. Accuracy of relativistic energy-consistent pseudopotentials for superheavy elements 111-118: Molecular calibration calculations

    SciTech Connect

    Hangele, Tim; Dolg, Michael

    2013-01-28

    Relativistic energy-consistent pseudopotentials modelling the Dirac-Coulomb-Breit Hamiltonian with a finite nucleus model for the superheavy elements with nuclear charges 111-118 were calibrated in atomic and molecular calculations against fully relativistic all-electron reference data. Various choices for the adjustment of the f-potentials were investigated and an improved parametrization is recommended. Using the resulting pseudopotentials relativistic all-electron reference data can be reproduced at the self-consistent field level with average absolute (relative) errors of 0.0030 A (0.15%) for bond lengths and 2.79 N m{sup -1} (1.26%) for force constants for 24 diatomic test molecules, i.e., neutral or singly charged monohydrides, monofluorides, and monochlorides with closed-shell electronic structure. At the second-order Moller-Plesset perturbation theory level the corresponding average deviations are 0.0033 A (0.15%) for bond lengths and 2.86 N m{sup -1} (1.40%) for force constants. Corresponding improved f-potentials were also derived for the pseudopotentials modelling in addition the leading contributions from quantum electrodynamics.

  2. High-order accurate physical-constraints-preserving finite difference WENO schemes for special relativistic hydrodynamics

    NASA Astrophysics Data System (ADS)

    Wu, Kailiang; Tang, Huazhong

    2015-10-01

    The paper develops high-order accurate physical-constraints-preserving finite difference WENO schemes for special relativistic hydrodynamical (RHD) equations, built on the local Lax-Friedrichs splitting, the WENO reconstruction, the physical-constraints-preserving flux limiter, and the high-order strong stability preserving time discretization. They are extensions of the positivity-preserving finite difference WENO schemes for the non-relativistic Euler equations [20]. However, developing physical-constraints-preserving methods for the RHD system becomes much more difficult than the non-relativistic case because of the strongly coupling between the RHD equations, no explicit formulas of the primitive variables and the flux vectors with respect to the conservative vector, and one more physical constraint for the fluid velocity in addition to the positivity of the rest-mass density and the pressure. The key is to prove the convexity and other properties of the admissible state set and discover a concave function with respect to the conservative vector instead of the pressure which is an important ingredient to enforce the positivity-preserving property for the non-relativistic case. Several one- and two-dimensional numerical examples are used to demonstrate accuracy, robustness, and effectiveness of the proposed physical-constraints-preserving schemes in solving RHD problems with large Lorentz factor, or strong discontinuities, or low rest-mass density or pressure etc.

  3. Second-order accurate kinetic schemes for the ultra-relativistic Euler equations

    NASA Astrophysics Data System (ADS)

    Kunik, Matthias; Qamar, Shamsul; Warnecke, Gerald

    2003-12-01

    A second-order accurate kinetic scheme for the numerical solution of the relativistic Euler equations is presented. These equations describe the flow of a perfect fluid in terms of the particle density n, the spatial part of the four-velocity u and the pressure p. The kinetic scheme, is based on the well-known fact that the relativistic Euler equations are the moments of the relativistic Boltzmann equation of the kinetic theory of gases when the distribution function is a relativistic Maxwellian. The kinetic scheme consists of two phases, the convection phase (free-flight) and collision phase. The velocity distribution function at the end of the free-flight is the solution of the collisionless transport equation. The collision phase instantaneously relaxes the distribution to the local Maxwellian distribution. The fluid dynamic variables of density, velocity, and internal energy are obtained as moments of the velocity distribution function at the end of the free-flight phase. The scheme presented here is an explicit method and unconditionally stable. The conservation laws of mass, momentum and energy as well as the entropy inequality are everywhere exactly satisfied by the solution of the kinetic scheme. The scheme also satisfies positivity and L1-stability. The scheme can be easily made into a total variation diminishing method for the distribution function through a suitable choice of the interpolation strategy. In the numerical case studies the results obtained from the first- and second-order kinetic schemes are compared with the first- and second-order upwind and central schemes. We also calculate the experimental order of convergence and numerical L1-stability of the scheme for smooth initial data.

  4. Accurate non-Born-Oppenheimer calculations of the complete pure vibrational spectrum of D2 with including relativistic corrections.

    PubMed

    Bubin, Sergiy; Stanke, Monika; Adamowicz, Ludwik

    2011-08-21

    In this work we report very accurate variational calculations of the complete pure vibrational spectrum of the D(2) molecule performed within the framework where the Born-Oppenheimer (BO) approximation is not assumed. After the elimination of the center-of-mass motion, D(2) becomes a three-particle problem in this framework. As the considered states correspond to the zero total angular momentum, their wave functions are expanded in terms of all-particle, one-center, spherically symmetric explicitly correlated Gaussian functions multiplied by even non-negative powers of the internuclear distance. The nonrelativistic energies of the states obtained in the non-BO calculations are corrected for the relativistic effects of the order of α(2) (where α = 1/c is the fine structure constant) calculated as expectation values of the operators representing these effects. PMID:21861559

  5. Accurate relativistic adapted Gaussian basis sets for francium through Ununoctium without variational prolapse and to be used with both uniform sphere and Gaussian nucleus models.

    PubMed

    Teodoro, Tiago Quevedo; Haiduke, Roberto Luiz Andrade

    2013-10-15

    Accurate relativistic adapted Gaussian basis sets (RAGBSs) for 87 Fr up to 118 Uuo atoms without variational prolapse were developed here with the use of a polynomial version of the Generator Coordinate Dirac-Fock method. Two finite nuclear models have been used, the Gaussian and uniform sphere models. The largest RAGBS error, with respect to numerical Dirac-Fock results, is 15.4 miliHartree for Ununoctium with a basis set size of 33s30p19d14f functions. PMID:23913741

  6. Relativistic regimes in which Compton scattering doubly differential cross sections obtained from impulse approximation are accurate due to cancelation of errors

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2015-05-01

    There is no simple parameter that can be used to predict when impulse approximation (IA) can yield accurate Compton scattering doubly differential cross sections (DDCS) in relativistic regimes. When Z is low, a small value of the parameter /q (where is the average initial electron momentum and q is the momentum transfer) suffices. For small Z the photon electron kinematic contribution described in relativistic S-matrix (SM) theory reduces to an expression, Xrel, which is present in the relativistic impulse approximation (RIA) formula for Compton DDCS. When Z is high, the S-Matrix photon electron kinematics no longer reduces to Xrel, and this along with the error characterized by the magnitude of /q contribute to the RIA error Δ. We demonstrate and illustrate in the form of contour plots that there are regimes of incident photon energy ωi and scattering angle θ in which the two types of errors at least partially cancel. Our calculations show that when θ is about 65° for Uranium K-shell scattering, Δ is less than 1% over an ωi range of 300 to 900 keV.

  7. Accurate ab initio potential energy curve of O2. II. Core-valence correlations, relativistic contributions, and vibration-rotation spectrum.

    PubMed

    Bytautas, Laimutis; Matsunaga, Nikita; Ruedenberg, Klaus

    2010-02-21

    In the first paper of this series, a very accurate ab initio potential energy curve of the (3)Sigma(g)(-) ground state of O(2) has been determined in the approximation that all valence shell electron correlations were calculated at the complete basis set limit. In the present study, the corrections arising from core electron correlations and relativity effects, viz., spin-orbit coupling and scalar relativity, are determined and added to the potential energy curve. From the 24 points calculated on this curve, an analytical expression in terms of even-tempered Gaussian functions is determined and, from it, the vibrational and rotational energy levels are calculated by means of the discrete variable representation. We find 42 vibrational levels. Experimental data (from the Schumann-Runge band system) only yield the lowest 36 levels due to significant reduction in the transition intensities of higher levels. For the 35 term values G(v), the mean absolute deviation between theoretical and experimental data is 12.8 cm(-1). The dissociation energy with respect to the lowest vibrational energy is calculated within 25 cm(-1) of the experimental value of 41,268.2+/-3 cm(-1). The theoretical crossing between the (3)Sigma(g)(-) state and the (1)Sigma(g)(+) state is found to occur at 2.22 A and the spin-orbit coupling in this region is analyzed. PMID:20170227

  8. Relativistic diffusion

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  9. Relativistic diffusion.

    PubMed

    Haba, Z

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed. PMID:19391727

  10. Accuracy of the non-relativistic approximation for momentum diffusion

    NASA Astrophysics Data System (ADS)

    Liang, Shiuan-Ni; Lan, Boon Leong

    2016-06-01

    The accuracy of the non-relativistic approximation, which is calculated using the same parameter and the same initial ensemble of trajectories, to relativistic momentum diffusion at low speed is studied numerically for a prototypical nonlinear Hamiltonian system -the periodically delta-kicked particle. We find that if the initial ensemble is a non-localized semi-uniform ensemble, the non-relativistic approximation to the relativistic mean square momentum displacement is always accurate. However, if the initial ensemble is a localized Gaussian, the non-relativistic approximation may not always be accurate and the approximation can break down rapidly.

  11. Relativistic geodesy

    NASA Astrophysics Data System (ADS)

    Flury, J.

    2016-06-01

    Quantum metrology enables new applications in geodesy, including relativistic geodesy. The recent progress in optical atomic clocks and in long-distance frequency transfer by optical fiber together pave the way for using measurements of the gravitational frequency redshift for geodesy. The remote comparison of frequencies generated by calibrated clocks will allow for a purely relativistic determination of differences in gravitational potential and height between stations on Earth surface (chronometric leveling). The long-term perspective is to tie potential and height differences to atomic standards in order to overcome the weaknesses and inhomogeneity of height systems determined by classical spirit leveling. Complementarily, gravity measurements with atom interferometric setups, and satellite gravimetry with space borne laser interferometers allow for new sensitivities in the measurement of the Earth's gravity field.

  12. Relativistic klystrons

    SciTech Connect

    Allen, M.A.; Azuma, O.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Hoag, H.A.; Koontz, R.F.

    1989-03-01

    Experimental work is underway by a SLAC-LLNL-LBL collaboration to investigate the feasibility of using relativistic klystrons as a power source for future high gradient accelerators. Two different relativistic klystron configurations have been built and tested to date: a high grain multicavity klystron at 11.4 GHz and a low gain two cavity subharmonic buncher driven at 5.7 GHz. In both configurations power is extracted at 11.4 GHz. In order to understand the basic physics issues involved in extracting RF from a high power beam, we have used both a single resonant cavity and a multi-cell traveling wave structure for energy extraction. We have learned how to overcome our previously reported problem of high power RF pulse shortening, and have achieved peak RF power levels of 170 MW with the RF pulse of the same duration as the beam current pulse. 6 refs., 3 figs., 3 tabs.

  13. Analytical potential curves of some hydride molecules using algebraic and energy-consistent method

    NASA Astrophysics Data System (ADS)

    Fan, Qunchao; Sun, Weiguo; Feng, Hao; Zhang, Yi; Wang, Qi

    2014-01-01

    Based on the algebraic method (AM) and the energy consistent method (ECM), an AM-ECM protocol for analytical potential energy curves of stable diatomic electronic states is proposed as functions of the internuclear distance. Applications of the AM-ECM to the 6 hydride electronic states of HF-X1Σ+, DF-X1Σ+, D35Cl-X1Σ+, 6LiH-X1Σ+, 7LiH-X1Σ+, and 7LiD-X1Σ+ show that the AM-ECM potentials are in excellent agreement with the experimental RKR data and the full AM-RKR data, and that the AM-ECM can obtain reliable analytical potential energies in the molecular asymptotic and dissociation region for these molecular electronic states.

  14. Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Jones, Bernard J. T.; Markovic, Dragoljub

    1997-06-01

    Preface; Prologue: Conference overview Bernard Carr; Part I. The Universe At Large and Very Large Redshifts: 2. The size and age of the Universe Gustav A. Tammann; 3. Active galaxies at large redshifts Malcolm S. Longair; 4. Observational cosmology with the cosmic microwave background George F. Smoot; 5. Future prospects in measuring the CMB power spectrum Philip M. Lubin; 6. Inflationary cosmology Michael S. Turner; 7. The signature of the Universe Bernard J. T. Jones; 8. Theory of large-scale structure Sergei F. Shandarin; 9. The origin of matter in the universe Lev A. Kofman; 10. New guises for cold-dark matter suspects Edward W. Kolb; Part II. Physics and Astrophysics Of Relativistic Compact Objects: 11. On the unification of gravitational and inertial forces Donald Lynden-Bell; 12. Internal structure of astrophysical black holes Werner Israel; 13. Black hole entropy: external facade and internal reality Valery Frolov; 14. Accretion disks around black holes Marek A. Abramowicz; 15. Black hole X-ray transients J. Craig Wheeler; 16. X-rays and gamma rays from active galactic nuclei Roland Svensson; 17. Gamma-ray bursts: a challenge to relativistic astrophysics Martin Rees; 18. Probing black holes and other exotic objects with gravitational waves Kip Thorne; Epilogue: the past and future of relativistic astrophysics Igor D. Novikov; I. D. Novikov's scientific papers and books.

  15. Relativistic causality

    NASA Astrophysics Data System (ADS)

    Valente, Giovanni; Owen Weatherall, James

    2014-11-01

    Relativity theory is often taken to include, or to imply, a prohibition on superluminal propagation of causal processes. Yet, what exactly the prohibition on superluminal propagation amounts to and how one should deal with its possible violation have remained open philosophical problems, both in the context of the metaphysics of causation and the foundations of physics. In particular, recent work in philosophy of physics has focused on the causal structure of spacetime in relativity theory and on how this causal structure manifests itself in our most fundamental theories of matter. These topics were the subject of a workshop on "Relativistic Causality in Quantum Field Theory and General Relativity" that we organized (along with John Earman) at the Center for Philosophy of Science in Pittsburgh on April 5-7, 2013. The present Special Issue comprises contributions by speakers in that workshop as well as several other experts exploring different aspects of relativistic causality. We are grateful to the journal for hosting this Special Issue, to the journal's managing editor, Femke Kuiling, for her help and support in putting the issue together, and to the authors and the referees for their excellent work.

  16. Relativistic fluid dynamics. Proceedings.

    NASA Astrophysics Data System (ADS)

    Anile, A. M.; Choquet-Bruhat, Y.

    Contents: 1. Covariant theory of conductivity in ideal fluid or solid media (B. Carter). 2. Hamiltonian techniques for relativistic fluid dynamics and stability theory (D. D. Holm). 3. Covariant fluid mechanics and thermodynamics: an introduction (W. Israel). 4. Relativistic plasmas (H. Weitzner). 5. An improved relativistic warm plasma model (A. M. Anile, S. Pennisi). 6. Relativistic extended thermodynamics II (I. Müller). 7. Relativistic extended thermodynamics: general assumptions and mathematical procedure (T. Ruggeri). 8. Relativistic hydrodynamics and heavy ion reactions (D. Strottman). 9. Some problems in relativistic hydrodynamics (C. G. van Weert).

  17. Relativistic electron beam generator

    DOEpatents

    Mooney, L.J.; Hyatt, H.M.

    1975-11-11

    A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

  18. Relativistic Guiding Center Equations

    SciTech Connect

    White, R. B.; Gobbin, M.

    2014-10-01

    In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.

  19. Relativistic Linear Restoring Force

    ERIC Educational Resources Information Center

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  20. Non-relativistic leptogenesis

    NASA Astrophysics Data System (ADS)

    Bödeker, Dietrich; Wörmann, Mirco

    2014-02-01

    In many phenomenologically interesting models of thermal leptogenesis the heavy neutrinos are non-relativistic when they decay and produce the baryon asymmetry of the Universe. We propose a non-relativistic approximation for the corresponding rate equations in the non-resonant case, and a systematic way for computing relativistic corrections. We determine the leading order coefficients in these equations, and the first relativistic corrections. The non-relativistic approximation works remarkably well. It appears to be consistent with results obtained using a Boltzmann equation taking into account the momentum distribution of the heavy neutrinos, while being much simpler. We also compute radiative corrections to some of the coefficients in the rate equations. Their effect is of order 1% in the regime favored by neutrino oscillation data. We obtain the correct leading order lepton number washout rate in this regime, which leads to large ( ~ 20%) effects compared to previous computations.

  1. Relativistic dynamics of the Compton diffusion on a bound electron

    NASA Astrophysics Data System (ADS)

    Al Saleh, Salwa

    2016-05-01

    A covariant relativistic formalism for the electron-photon and nuclear dynamics is summarised making more accurate predictions in agreement with experiments for Compton scattering in shells with large electron binding energy. An exact solution for the Dirac equation for an electron in the nuclear Coulomb field is obtained, in order to write the relativistic dynamics for this QED process. This is a preparation for the calculation of the relativistic cross-section for Compton scattering on bound electrons, as a precision test for QED.

  2. Multiple scattering calculations of relativistic electron energy loss spectra

    NASA Astrophysics Data System (ADS)

    Jorissen, K.; Rehr, J. J.; Verbeeck, J.

    2010-04-01

    A generalization of the real-space Green’s-function approach is presented for ab initio calculations of relativistic electron energy loss spectra (EELS) which are particularly important in anisotropic materials. The approach incorporates relativistic effects in terms of the transition tensor within the dipole-selection rule. In particular, the method accounts for relativistic corrections to the magic angle in orientation resolved EELS experiments. The approach is validated by a study of the graphite CK edge, for which we present an accurate magic angle measurement consistent with the predicted value.

  3. Magnetogenesis through Relativistic Velocity Shear

    NASA Astrophysics Data System (ADS)

    Miller, Evan

    Magnetic fields at all scales are prevalent in our universe. However, current cosmological models predict that initially the universe was bereft of large-scale fields. Standard magnetohydrodynamics (MHD) does not permit magnetogenesis; in the MHD Faraday's law, the change in magnetic field B depends on B itself. Thus if B is initially zero, it will remain zero for all time. A more accurate physical model is needed to explain the origins of the galactic-scale magnetic fields observed today. In this thesis, I explore two velocity-driven mechanisms for magnetogenesis in 2-fluid plasma. The first is a novel kinematic 'battery' arising from convection of vorticity. A coupling between thermal and plasma oscillations, this non-relativistic mechanism can operate in flows that are incompressible, quasi-neutral and barotropic. The second mechanism results from inclusion of thermal effects in relativistic shear flow instabilities. In such flows, parallel perturbations are ubiquitously unstable at small scales, with growth rates of order with the plasma frequency over a defined range of parameter-space. Of these two processes, instabilities seem far more likely to account for galactic magnetic fields. Stable kinematic effects will, at best, be comparable to an ideal Biermann battery, which is suspected to be orders of magnitude too weak to produce the observed galactic fields. On the other hand, instabilities grow until saturation is reached, a topic that has yet to be explored in detail on cosmological scales. In addition to investigating these magnetogenesis sources, I derive a general dispersion relation for three dimensional, warm, two species plasma with discontinuous shear flow. The mathematics of relativistic plasma, sheared-flow instability and the Biermann battery are also discussed.

  4. Weakly relativistic plasma expansion

    SciTech Connect

    Fermous, Rachid Djebli, Mourad

    2015-04-15

    Plasma expansion is an important physical process that takes place in laser interactions with solid targets. Within a self-similar model for the hydrodynamical multi-fluid equations, we investigated the expansion of both dense and under-dense plasmas. The weakly relativistic electrons are produced by ultra-intense laser pulses, while ions are supposed to be in a non-relativistic regime. Numerical investigations have shown that relativistic effects are important for under-dense plasma and are characterized by a finite ion front velocity. Dense plasma expansion is found to be governed mainly by quantum contributions in the fluid equations that originate from the degenerate pressure in addition to the nonlinear contributions from exchange and correlation potentials. The quantum degeneracy parameter profile provides clues to set the limit between under-dense and dense relativistic plasma expansions at a given density and temperature.

  5. Relativistic Hall effect.

    PubMed

    Bliokh, Konstantin Y; Nori, Franco

    2012-03-23

    We consider the relativistic deformation of quantum waves and mechanical bodies carrying intrinsic angular momentum (AM). When observed in a moving reference frame, the centroid of the object undergoes an AM-dependent transverse shift. This is the relativistic analogue of the spin-Hall effect, which occurs in free space without any external fields. Remarkably, the shifts of the geometric and energy centroids differ by a factor of 2, and both centroids are crucial for the Lorentz transformations of the AM tensor. We examine manifestations of the relativistic Hall effect in quantum vortices and mechanical flywheels and also discuss various fundamental aspects of this phenomenon. The perfect agreement of quantum and relativistic approaches allows applications at strikingly different scales, from elementary spinning particles, through classical light, to rotating black holes. PMID:22540559

  6. Exact Relativistic `Antigravity' Propulsion

    NASA Astrophysics Data System (ADS)

    Felber, Franklin S.

    2006-01-01

    The Schwarzschild solution is used to find the exact relativistic motion of a payload in the gravitational field of a mass moving with constant velocity. At radial approach or recession speeds faster than 3-1/2 times the speed of light, even a small mass gravitationally repels a payload. At relativistic speeds, a suitable mass can quickly propel a heavy payload from rest nearly to the speed of light with negligible stresses on the payload.

  7. Relativistic Quantum Scars

    SciTech Connect

    Huang, Liang; Lai Yingcheng; Ferry, David K.; Goodnick, Stephen M.; Akis, Richard

    2009-07-31

    The concentrations of wave functions about classical periodic orbits, or quantum scars, are a fundamental phenomenon in physics. An open question is whether scarring can occur in relativistic quantum systems. To address this question, we investigate confinements made of graphene whose classical dynamics are chaotic and find unequivocal evidence of relativistic quantum scars. The scarred states can lead to strong conductance fluctuations in the corresponding open quantum dots via the mechanism of resonant transmission.

  8. Relativistic viscoelastic fluid mechanics

    SciTech Connect

    Fukuma, Masafumi; Sakatani, Yuho

    2011-08-15

    A detailed study is carried out for the relativistic theory of viscoelasticity which was recently constructed on the basis of Onsager's linear nonequilibrium thermodynamics. After rederiving the theory using a local argument with the entropy current, we show that this theory universally reduces to the standard relativistic Navier-Stokes fluid mechanics in the long time limit. Since effects of elasticity are taken into account, the dynamics at short time scales is modified from that given by the Navier-Stokes equations, so that acausal problems intrinsic to relativistic Navier-Stokes fluids are significantly remedied. We in particular show that the wave equations for the propagation of disturbance around a hydrostatic equilibrium in Minkowski space-time become symmetric hyperbolic for some range of parameters, so that the model is free of acausality problems. This observation suggests that the relativistic viscoelastic model with such parameters can be regarded as a causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting parameters to various values, this theory can treat a wide variety of materials including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus we expect the theory to be the most universal description of single-component relativistic continuum materials. We also show that the presence of strains and the corresponding change in temperature are naturally unified through the Tolman law in a generally covariant description of continuum mechanics.

  9. A simple approximation for the current-voltage characteristics of high-power, relativistic diodes

    NASA Astrophysics Data System (ADS)

    Ekdahl, Carl

    2016-06-01

    A simple approximation for the current-voltage characteristics of a relativistic electron diode is presented. The approximation is accurate from non-relativistic through relativistic electron energies. Although it is empirically developed, it has many of the fundamental properties of the exact diode solutions. The approximation is simple enough to be remembered and worked on almost any pocket calculator, so it has proven to be quite useful on the laboratory floor.

  10. A simple approximation for the current-voltage characteristics of high-power, relativistic diodes

    DOE PAGESBeta

    Ekdahl, Carl

    2016-06-01

    A simple approximation for the current-voltage characteristics of a relativistic electron diode is presented. The approximation is accurate from non-relativistic through relativistic electron energies. Although it is empirically developed, it has many of the fundamental properties of the exact diode solutions. Lastly, the approximation is simple enough to be remembered and worked on almost any pocket calculator, so it has proven to be quite useful on the laboratory floor.

  11. A simple approximation for the current-voltage characteristics of high-power, relativistic diodes.

    PubMed

    Ekdahl, Carl

    2016-06-01

    A simple approximation for the current-voltage characteristics of a relativistic electron diode is presented. The approximation is accurate from non-relativistic through relativistic electron energies. Although it is empirically developed, it has many of the fundamental properties of the exact diode solutions. The approximation is simple enough to be remembered and worked on almost any pocket calculator, so it has proven to be quite useful on the laboratory floor. PMID:27370443

  12. Relativistic Weierstrass random walks.

    PubMed

    Saa, Alberto; Venegeroles, Roberto

    2010-08-01

    The Weierstrass random walk is a paradigmatic Markov chain giving rise to a Lévy-type superdiffusive behavior. It is well known that special relativity prevents the arbitrarily high velocities necessary to establish a superdiffusive behavior in any process occurring in Minkowski spacetime, implying, in particular, that any relativistic Markov chain describing spacetime phenomena must be essentially Gaussian. Here, we introduce a simple relativistic extension of the Weierstrass random walk and show that there must exist a transition time t{c} delimiting two qualitative distinct dynamical regimes: the (nonrelativistic) superdiffusive Lévy flights, for trelativistic) Gaussian diffusion, for t>t{c} . Implications of this crossover between different diffusion regimes are discussed for some explicit examples. The study of such an explicit and simple Markov chain can shed some light on several results obtained in much more involved contexts. PMID:20866862

  13. SAMPEX Relativistic Microbursts Observation

    NASA Astrophysics Data System (ADS)

    Liang, X.; Comess, M.; Smith, D. M.; Selesnick, R. S.; Sample, J. G.; Millan, R. M.

    2012-12-01

    Relativistic (>1 MeV) electron microburst precipitation is thought to account for significant relativistic electron loss. We present the statistical and spectral analysis of relativistic microbursts observed by the Proton/Electron Telescope (PET) on board the Solar Anomalous Magnetospheric Particle Explorer(SAMPEX) satellite from 1992 to 2004. Spectrally we find that microbursts are well fit by an exponential energy distribution in the 0.5-4 MeV range with a spectral e-folding energy of E0 < 375 keV. We also discuss the comparison of morning microbursts with events at midnight, which were first identified as microbursts by O'Brien et al. (2004). Finally, we compare the loss-rates due to microbursts and non-microburst precipitation during storm times and averaged over all times.

  14. Relativistic nuclear dynamics

    SciTech Connect

    Coester, F.

    1985-01-01

    A review is presented of three distinct approaches to the construction of relativistic dynamical models: (1) Relativistic canonical quantum mechanics. (The Hilbert space of states is independent of the interactions, which are introduced by modifying the energy operator.) (2) Hilbert spaces of manifestly covariant wave functions. (The interactions modify the metric of the Hilbert space.) (3) Covariant Green functions. In each of the three approaches the focus is on the formulation of the two-body dynamics, and problems in the construction of the corresponding many-body dynamics are discussed briefly. 21 refs.

  15. Perspective: relativistic effects.

    PubMed

    Autschbach, Jochen

    2012-04-21

    This perspective article discusses some broadly-known and some less broadly-known consequences of Einstein's special relativity in quantum chemistry, and provides a brief outline of the theoretical methods currently in use, along with a discussion of recent developments and selected applications. The treatment of the electron correlation problem in relativistic quantum chemistry methods, and expanding the reach of the available relativistic methods to calculate all kinds of energy derivative properties, in particular spectroscopic and magnetic properties, requires on-going efforts. PMID:22519307

  16. Relativistic and quantum electrodynamic effects in superheavy elements

    NASA Astrophysics Data System (ADS)

    Schwerdtfeger, Peter; Pašteka, Lukáš F.; Punnett, Andrew; Bowman, Patrick O.

    2015-12-01

    The current status of relativistic electronic structure theory for superheavy elements is reviewed. Recent developments in relativistic quantum theory have made it possible to obtain accurate electronic properties for the trans-actinide elements with the aim to predict their chemical and physical behaviour. The role of quantum electrodynamic effects beyond the no-virtual-pair approximation, which is usually neglected in relativistic molecular calculations, is discussed. Changes in periodic trends due to relativistic effects are outlined for the superheavy elements with nuclear charge Z = 111- 120. We also analyse the role of the negative energy states for the electronic stability of superheavy elements beyond the critical nuclear charge (Zcrit ≈ 170), where the 1s state enters the negative energy continuum at - 2mec2.

  17. Synchrotron emissivity from mildly relativistic particles

    NASA Technical Reports Server (NTRS)

    Petrosian, V.

    1981-01-01

    Approximate analytic expressions are presented for evaluation of the frequency and angular dependence of synchrotron emissivity from mildly relativistic particles with arbitrary energy spectrum and pitch angle distribution in a given magnetic field. Results agree with previous expressions for a nonrelativistic Maxwellian particle distribution, and when extrapolated to nonrelativistic and extreme relativistic regimes, they also agree with the previous expressions obtained under those limiting conditions. The results from the analytic expression are compared with results from detailed numerical evaluations. Excellent agreement is found not only at frequencies large compared to the gyro-frequency but also at lower frequencies, in fact, all the way down to the gyro-frequency, where the analytic approximations are expected to be less accurate.

  18. Relativistic impulse dynamics.

    PubMed

    Swanson, Stanley M

    2011-08-01

    Classical electrodynamics has some annoying rough edges. The self-energy of charges is infinite without a cutoff. The calculation of relativistic trajectories is difficult because of retardation and an average radiation reaction term. By reconceptuallizing electrodynamics in terms of exchanges of impulses rather than describing it by forces and potentials, we eliminate these problems. A fully relativistic theory using photonlike null impulses is developed. Numerical calculations for a two-body, one-impulse-in-transit model are discussed. A simple relationship between center-of-mass scattering angle and angular momentum was found. It reproduces the Rutherford cross section at low velocities and agrees with the leading term of relativistic distinguishable-particle quantum cross sections (Møller, Mott) when the distance of closest approach is larger than the Compton wavelength of the particle. Magnetism emerges as a consequence of viewing retarded and advanced interactions from the vantage point of an instantaneous radius vector. Radiation reaction becomes the local conservation of energy-momentum between the radiating particle and the emitted impulse. A net action is defined that could be used in developing quantum dynamics without potentials. A reinterpretation of Newton's laws extends them to relativistic motion. PMID:21929132

  19. Radiation from Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Sol, H.; Medvedev, M.; Zhang, B.; Nordlund, A.; Frederiksen, J. T.; Fishman, G. J.; Preece, R.

    2008-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electron-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the presence of relativistic jets, instabilities such as the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability create collisionless shocks, which are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons in small-scale magnetic fields has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation, a case of diffusive synchrotron radiation, may be important to understand the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  20. A relativistic spherical vortex

    PubMed Central

    Pekeris, C. L.

    1976-01-01

    This investigation is concerned with stationary relativistic flows of an inviscid and incompressible fluid. In choosing a density-pressure relation to represent relativistic “incompressibility,” it is found that a fluid in which the velocity of sound equals the velocity of light is to be preferred for reasons of mathematical simplicity. In the case of axially symmetric flows, the velocity field can be derived from a stream function obeying a partial differential equation which is nonlinear. A transformation of variables is found which makes the relativistic differential equation linear. An exact solution is obtained for the case of a vortex confined to a stationary sphere. One can make all three of the components of velocity vanish on the surface of the sphere, as in the nonrelativistic Hicks spherical vortex. In the case of an isolated vortex on whose surface the pressure is made to vanish, it is found that the pressure at the center of the sphere becomes negative, as in the nonrelativistic case. A solution is also obtained for a relativistic vortex advancing in a fluid. The sphere is distorted into an oblate spheroid. The maximum possible velocity of advance of the vortex is (2/3) c. PMID:16578745

  1. The Relativistic Rocket

    ERIC Educational Resources Information Center

    Antippa, Adel F.

    2009-01-01

    We solve the problem of the relativistic rocket by making use of the relation between Lorentzian and Galilean velocities, as well as the laws of superposition of successive collinear Lorentz boosts in the limit of infinitesimal boosts. The solution is conceptually simple, and technically straightforward, and provides an example of a powerful…

  2. Relativistic effects on plasma expansion

    SciTech Connect

    Benkhelifa, El-Amine; Djebli, Mourad

    2014-07-15

    The expansion of electron-ion plasma is studied through a fully relativistic multi-fluids plasma model which includes thermal pressure, ambipolar electrostatic potential, and internal energy conversion. Numerical investigation, based on quasi-neutral assumption, is performed for three different regimes: nonrelativistic, weakly relativistic, and relativistic. Ions' front in weakly relativistic regime exhibits spiky structure associated with a break-down of quasi-neutrality at the expanding front. In the relativistic regime, ion velocity is found to reach a saturation limit which occurs at earlier stages of the expansion. This limit is enhanced by higher electron velocity.

  3. Dynamics of relativistic jets

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Frank, J.; Christodoulou, D. M.; Koide, S.; Sakai, J.-I.; Sol, Hélène; Mutel, Robert L.

    1998-12-01

    We discuss the structure and relativistic kinematics that develop in three spatial dimensions when a moderately hot, supersonic jet propagates into a denser background medium and encounters resistance from an oblique magnetic field. Our simulations incorporate relativistic MHD in a four-dimensional spacetime and clearly show that (a) relatively weak, oblique fields (at 1/16 of the equipartition value) have only a negligible influence on the propagating jet and they are passively pushed away by the relativistically moving head; (b) oblique fields in equipartition with the ambient plasma provide more resistance and cause bending at the jet head, but the magnitude of this deflection and the associated backflow are small compared to those identified by previous studies. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently during the simulations. The effect is analogous to pushing Japanese "noren" or vertical Venetian blinds out of the way while the slats are allowed to bend and twist in 3-D space. Applied to relativistic extragalactic jets from blazars, the new results are encouraging since superluminal outflows exhibit bending near their sources and their environments are profoundly magnetized - but observations do not provide support for irregular kinematics such as large-scale vortical motions and pronounced reverse flows near the points of origin.

  4. Predicting Mercury's precession using simple relativistic Newtonian dynamics

    NASA Astrophysics Data System (ADS)

    Friedman, Y.; Steiner, J. M.

    2016-03-01

    We present a new simple relativistic model for planetary motion describing accurately the anomalous precession of the perihelion of Mercury and its origin. The model is based on transforming Newton's classical equation for planetary motion from absolute to real spacetime influenced by the gravitational potential and introducing the concept of influenced direction.

  5. Relativistic radiative transfer and relativistic plane-parallel flows

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2015-04-01

    Relativistic radiative transfer and relativistic plane-parallel flows accelerated from their base like accretion disk winds are numerically examined under the special relativistic treatment. We first solve the relativistic transfer equation iteratively, using a given velocity field, and obtain specific intensities as well as moment quantities. Using the obtained flux, we then solve the hydrodynamical equation, and obtain the new velocity field and the mass-loss rate as an eigen value. We repeat these double-iteration processes until both the intensity and velocity profiles converge. Under this double iteration, we solve the relativistic radiative transfer equation and relativistic flows in the vertical direction, simultaneously. The flows are gradually accelerated, as the optical depth decreases towards the surface. The mass-loss rate dot{J} is roughly expressed in terms of the optical depth τb and terminal speed βs of the flow as dot{J} ˜ 10 τ_b β _s^{-3/4}.

  6. Local relativistic exact decoupling.

    PubMed

    Peng, Daoling; Reiher, Markus

    2012-06-28

    We present a systematic hierarchy of approximations for local exact decoupling of four-component quantum chemical Hamiltonians based on the Dirac equation. Our ansatz reaches beyond the trivial local approximation that is based on a unitary transformation of only the atomic block-diagonal part of the Hamiltonian. Systematically, off-diagonal Hamiltonian matrix blocks can be subjected to a unitary transformation to yield relativistically corrected matrix elements. The full hierarchy is investigated with respect to the accuracy reached for the electronic energy and for selected molecular properties on a balanced test molecule set that comprises molecules with heavy elements in different bonding situations. Our atomic (local) assembly of the unitary exact-decoupling transformation--called local approximation to the unitary decoupling transformation (DLU)--provides an excellent local approximation for any relativistic exact-decoupling approach. Its order-N(2) scaling can be further reduced to linear scaling by employing a neighboring-atomic-blocks approximation. Therefore, DLU is an efficient relativistic method well suited for relativistic calculations on large molecules. If a large molecule contains many light atoms (typically hydrogen atoms), the computational costs can be further reduced by employing a well-defined nonrelativistic approximation for these light atoms without significant loss of accuracy. We also demonstrate that the standard and straightforward transformation of only the atomic block-diagonal entries in the Hamiltonian--denoted diagonal local approximation to the Hamiltonian (DLH) in this paper--introduces an error that is on the order of the error of second-order Douglas-Kroll-Hess (i.e., DKH2) when compared with exact-decoupling results. Hence, the local DLH approximation would be pointless in an exact-decoupling framework, but can be efficiently employed in combination with the fast to evaluate DKH2 Hamiltonian in order to speed up calculations

  7. Relativistic hadrons and the origin of relativistic outflows in active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Contopoulos, John; Kazanas, D.

    1995-01-01

    We examine the hydrodynamic origin of relativistic outflows in active galactic nuclei (AGN). Specifically, we propose that the presence of a population of relativistic hadrons in the AGN 'central engine' and the associated neutron production suffices to produce outflows which under rather general conditions could be relativistic. The main such condition is that the size of the neutron production region be larger than the neutron flight path tau(sub n) approximately 3 x 10(exp 13) cm. This condition guarantees that the mean energy per particle in the proton fluid, resulting from the decay of the neutrons outside their production region, be greater than the proton rest mass. The expansion of this fluid can then lead naturally to a relativistic outflow by conversion of its internal energy to directed motion. We follow the development of such flows by solving the mass, energy as well as the kinetic equation for the proton gas in steady state, taking into account the source terms due to compute accurately the adiabatic index of the expanding gas, and in conjunction with Bernoulli's equation the detailed evolution of the bulk Lorentz factor. We further examine the role of large-scale magnetic fields in confining these outflows to produce the jets observed at larger scales.

  8. Relativistic tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2012-12-01

    In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like) galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s-1 at peak), rapid X-ray variability (factors of >100 on timescales of 100 seconds) and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ˜ 2 - 5), created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  9. Point form relativistic quantum mechanics and relativistic SU(6)

    NASA Technical Reports Server (NTRS)

    Klink, W. H.

    1993-01-01

    The point form is used as a framework for formulating a relativistic quantum mechanics, with the mass operator carrying the interactions of underlying constituents. A symplectic Lie algebra of mass operators is introduced from which a relativistic harmonic oscillator mass operator is formed. Mass splittings within the degenerate harmonic oscillator levels arise from relativistically invariant spin-spin, spin-orbit, and tensor mass operators. Internal flavor (and color) symmetries are introduced which make it possible to formulate a relativistic SU(6) model of baryons (and mesons). Careful attention is paid to the permutation symmetry properties of the hadronic wave functions, which are written as polynomials in Bargmann spaces.

  10. General relativistic observables for the ACES experiment

    NASA Astrophysics Data System (ADS)

    Turyshev, Slava G.; Yu, Nan; Toth, Viktor T.

    2016-02-01

    We develop a high-precision model for relativistic observables of the Atomic Clock Ensemble in Space (ACES) experiment on the International Space Station (ISS). We develop all relativistic coordinate transformations that are needed to describe the motion of ACES in Earth orbit and to compute observable quantities. We analyze the accuracy of the required model as it applies to the proper-to-coordinate time transformations, light-time equation, and spacecraft equations of motion. We consider various sources of nongravitational noise and their effects on ACES. We estimate the accuracy of orbit reconstruction that is needed to satisfy the ACES science objectives. Based on our analysis, we derive models for the relativistic observables of ACES, which also account for the contribution of atmospheric drag on the clock rate. We include the Earth's oblateness coefficient J2 and the effects of major nongravitational forces on the orbit of the ISS. We demonstrate that the ACES reference frame is pseudoinertial at the level of accuracy required by the experiment. We construct a Doppler-canceled science observable representing the gravitational redshift. We derive accuracy requirements for ISS navigation. The improved model is accurate up to <1 ps and ˜4 ×1 0-17 for time and frequency transfers, correspondingly. These limits are determined by the higher-order harmonics in Earth's gravitational potential.

  11. Relativistic apsidal motion in eccentric eclipsing binaries

    NASA Astrophysics Data System (ADS)

    Wolf, M.; Claret, A.; Kotková, L.; Kučáková, H.; Kocián, R.; Brát, L.; Svoboda, P.; Šmelcer, L.

    2010-01-01

    Context. The study of apsidal motion in detached eclipsing binary systems is known to be an important source of information about stellar internal structure as well as the possibility of verifying of General Relativity outside the Solar System. Aims: As part of the long-term Ondřejov and Ostrava observational projects, we aim to measure precise times of minima for eccentric eclipsing binaries, needed for the accurate determination of apsidal motion, providing a suitable test of the effects of General Relativity. Methods: About seventy new times of minimum light recorded with photoelectric or CCD photometers were obtained for ten eccentric-orbit eclipsing binaries with significant relativistic apsidal motion. Their O-C diagrams were analysed using all reliable timings found in the literature, and new or improved elements of apsidal motion were obtained. Results: We confirm very long periods of apsidal motion for all systems. For BF Dra and V1094 Tau, we present the first apsidal-motion solution. The relativistic effects are dominant, representing up to 100% of the total observable apsidal-motion rate in several systems. The theoretical and observed values of the internal structure constant k 2 were compared for systems with lower relativistic contribution. Using the light-time effect solution, we predict a faint third component for V1094 Tau orbiting with a short period of about 8 years. Partly based on photoelectric observations secured at the Hvar Observatory, Faculty of Geodesy, Zagreb, Croatia, in October 2008.

  12. Relativistic kinetic theory of magnetoplasmas

    SciTech Connect

    Beklemishev, Alexei; Nicolini, Piero; Tessarotto, Massimo

    2005-05-16

    Recently, an increasing interest in astrophysical as well as laboratory plasmas has been manifested in reference to the existence of relativistic flows, related in turn to the production of intense electric fields in magnetized systems. Such phenomena require their description in the framework of a consistent relativistic kinetic theory, rather than on relativistic MHD equations, subject to specific closure conditions. The purpose of this work is to apply the relativistic single-particle guiding-center theory developed by Beklemishev and Tessarotto, including the nonlinear treatment of small-wavelength EM perturbations which may naturally arise in such systems. As a result, a closed set of relativistic gyrokinetic equations, consisting of the collisionless relativistic kinetic equation, expressed in hybrid gyrokinetic variables, and the averaged Maxwell's equations, is derived for an arbitrary four-dimensional coordinate system.

  13. Observation of relativistic antihydrogen atoms

    SciTech Connect

    Blanford, Glenn DelFosse

    1998-01-01

    An observation of relativistic antihydrogen atoms is reported in this dissertation. Experiment 862 at Fermi National Accelerator Laboratory observed antihydrogen atoms produced by the interaction of a circulating beam of high momentum (3 < p < 9 GeV/c) antiprotons and a jet of molecular hydrogen gas. Since the neutral antihydrogen does not bend in the antiproton source magnets, the detectors could be located far from the interaction point on a beamline tangent to the storage ring. The detection of the antihydrogen is accomplished by ionizing the atoms far from the interaction point. The positron is deflected by a magnetic spectrometer and detected, as are the back to back photons resulting from its annihilation. The antiproton travels a distance long enough for its momentum and time of flight to be measured accurately. A statistically significant sample of 101 antihydrogen atoms has been observed. A measurement of the cross section for {bar H}{sup 0} production is outlined within. The cross section corresponds to the process where a high momentum antiproton causes e{sup +} e{sup -} pair creation near a nucleus with the e{sup +} being captured by the antiproton. Antihydrogen is the first atom made exclusively of antimatter to be detected. The observation experiment's results are the first step towards an antihydrogen spectroscopy experiment which would measure the n = 2 Lamb shift and fine structure.

  14. Relativistic klystron afterburner simulation techniques

    SciTech Connect

    Ryne, R.D.; Jong, R.A.; Westenskow, G.A.; Yu, S.S.

    1990-01-24

    We are developing computer codes for the numerical simulations of relativistic klystrons and relativistic klystron afterburners''. The purpose of this note is to discuss the main features of our numerical model. A relativistic klystron afterburner'' is a scheme to extract power from a spent FEL electron beam. Power is extracted from the beam by passing it through klystron output cavities. To study the feasibility of this concept, we are developing computer codes for the numerical simulation of relativistic klystrons and afterburners. The purpose of this note is to discuss the main features of our numerical model.

  15. Relativistic interactions and realistic applications

    SciTech Connect

    Hoch, T.; Madland, D.; Manakos, P.; Mannel, T.; Nikolaus, B.A.; Strottman, D. |

    1992-12-31

    A four-fermion-coupling Lagrangian (relativistic Skyrme-type) interaction has been proposed for relativistic nuclear structure calculations. This interaction, which has the merit of simplicity, is from the outset tailored as an effective interaction for relativistic Hartree-Fock calculations. Various extensions of such a model are discussed and compared with Walecka`s meson-nucleon mean field approach. We also present results of the calculation of nuclear ground state properties with an extended (density dependent) version of the four fermion interaction in a relativistic Hartree-Fock approximation.

  16. Relativistic Quantum Communication

    NASA Astrophysics Data System (ADS)

    Hosler, Dominic

    In this Ph.D. thesis, I investigate the communication abilities of non-inertial observers and the precision to which they can measure parametrized states. I introduce relativistic quantum field theory with field quantisation, and the definition and transformations of mode functions in Minkowski, Schwarzschild and Rindler spaces. I introduce information theory by discussing the nature of information, defining the entropic information measures, and highlighting the differences between classical and quantum information. I review the field of relativistic quantum information. We investigate the communication abilities of an inertial observer to a relativistic observer hovering above a Schwarzschild black hole, using the Rindler approximation. We compare both classical communication and quantum entanglement generation of the state merging protocol, for both the single and dual rail encodings. We find that while classical communication remains finite right up to the horizon, the quantum entanglement generation tends to zero. We investigate the observers' abilities to precisely measure the parameter of a state that is communicated between Alice and Rob. This parameter was encoded to either the amplitudes of a single excitation state or the phase of a NOON state. With NOON states the dual rail encoding provided greater precision, which is different to the results for the other situations. The precision was maximum for a particular number of excitations in the NOON state. We calculated the bipartite communication for Alice-Rob and Alice-AntiRob beyond the single mode approximation. Rob and AntiRob are causally disconnected counter-accelerating observers. We found that Alice must choose in advance with whom, Rob or AntiRob she wants to create entanglement using a particular setup. She could communicate classically to both.

  17. Frequency agile relativistic magnetrons

    SciTech Connect

    Levine, J.S.; Harteneck, B.D.; Price, H.D.

    1995-11-01

    The authors are developing a family of frequency agile relativistic magnetrons to continuously cover the bands from 1 to 3 GHz. They have achieved tuning ranges of > 33%. The magnetrons have been operated repetitively in burst mode at rates up to 100 pps for 10 sec. Power is extracted from two resonators, and is in the range of 400--600 MW, fairly flat across the tuning bandwidth. They are using a network of phase shifters and 3-dB hybrids to combine the power into a single arm and to provide a continuously adjustable attenuator.

  18. Republication of: Relativistic cosmology

    NASA Astrophysics Data System (ADS)

    Robertson, H. P.

    2012-08-01

    This is a reprinting of the paper by Howard Percy Robertson, first published in 1933 in Rev. Mod. Phys., that is a very authoritative summary of relativistic cosmology at the stage at which it was up to 1933. The paper has been selected by the Editors of General Relativity and Gravitation for re-publication in the Golden Oldies series of the journal. This republication is accompanied by an editorial note written by George Ellis, and by Robertson's biography, compiled by Andrzej Krasinski from printed sources.

  19. Newtonian and relativistic cosmologies

    NASA Astrophysics Data System (ADS)

    Green, Stephen R.; Wald, Robert M.

    2012-03-01

    Cosmological N-body simulations are now being performed using Newtonian gravity on scales larger than the Hubble radius. It is well known that a uniformly expanding, homogeneous ball of dust in Newtonian gravity satisfies the same equations as arise in relativistic Friedmann-Lemaître-Robinson-Walker cosmology, and it also is known that a correspondence between Newtonian and relativistic dust cosmologies continues to hold in linearized perturbation theory in the marginally bound/spatially flat case. Nevertheless, it is far from obvious that Newtonian gravity can provide a good global description of an inhomogeneous cosmology when there is significant nonlinear dynamical behavior at small scales. We investigate this issue in the light of a perturbative framework that we have recently developed [S. R. Green and R. M. Wald, Phys. Rev. DPRVDAQ1550-7998 83, 084020 (2011).10.1103/PhysRevD.83.084020], which allows for such nonlinearity at small scales. We propose a relatively straightforward dictionary—which is exact at the linearized level—that maps Newtonian dust cosmologies into general relativistic dust cosmologies, and we use our “ordering scheme” to determine the degree to which the resulting metric and matter distribution solve Einstein’s equation. We find that, within our ordering scheme, Einstein’s equation fails to hold at “order 1” at small scales and at “order ɛ” at large scales. We then find the additional corrections to the metric and matter distribution needed to satisfy Einstein’s equation to these orders. While these corrections are of some interest in their own right, our main purpose in calculating them is that their smallness should provide a criterion for the validity of the original dictionary (as well as simplified versions of this dictionary). We expect that, in realistic Newtonian cosmologies, these additional corrections will be very small; if so, this should provide strong justification for the use of Newtonian simulations

  20. Relativistic nuclear collisions: theory

    SciTech Connect

    Gyulassy, M.

    1980-07-01

    Some of the recent theoretical developments in relativistic (0.5 to 2.0-GeV/nucleon) nuclear collisions are reviewed. The statistical model, hydrodynamic model, classical equation of motion calculations, billiard ball dynamics, and intranuclear cascade models are discussed in detail. Inclusive proton and pion spectra are analyzed for a variety of reactions. Particular attention is focused on how the complex interplay of the basic reaction mechanism hinders attempts to deduce the nuclear matter equation of state from data. 102 references, 19 figures.

  1. Ultrabaric relativistic superfluids

    NASA Astrophysics Data System (ADS)

    Papini, G.; Weiss, M.

    1985-09-01

    Ultrabaric superfluid solutions are obtained for Einstein's equations to examine the possibility of the existence of superluminal sound speeds. The discussion is restricted only by requiring the energy-momentum tensor and the equation of state of matter to be represented by full relativistic equations. Only a few universes are known to satisfy the conditions, and those exhibit tension and are inflationary. Superluminal sound velocities are shown, therefore, to be possible for the interior Schwarzchild metric, which has been used to explain the red shift of quasars, and the Stephiani solution (1967). The latter indicates repeated transitions between superluminal and subliminal sound velocities in the hyperbaric superfluid of the early universe.

  2. Modeling relativistic nuclear collisions.

    SciTech Connect

    Anderlik, C.; Magas, V.; Strottman, D.; Csernai, L. P.

    2001-01-01

    Modeling Ultra-Relativistic Heavy Ion Collisioiis at RHIC and LHC energies using a Multi Module Model is presented. The first Module is the Effective String Rope Model for the calculation of the initial stages of the reaction; the output of this module is used as the initial state for the subsequent one-fluid hydrodynainical calculation module. It is shown that such an initial state leads to the creation of the third flow component. The hydrodynamical evolution of the energy density distribution is presented for RHIC energies. The final module describing the Freeze Out; and Hadronization is also discussed.

  3. Grading More Accurately

    ERIC Educational Resources Information Center

    Rom, Mark Carl

    2011-01-01

    Grades matter. College grading systems, however, are often ad hoc and prone to mistakes. This essay focuses on one factor that contributes to high-quality grading systems: grading accuracy (or "efficiency"). I proceed in several steps. First, I discuss the elements of "efficient" (i.e., accurate) grading. Next, I present analytical results…

  4. A Simple Relativistic Bohr Atom

    ERIC Educational Resources Information Center

    Terzis, Andreas F.

    2008-01-01

    A simple concise relativistic modification of the standard Bohr model for hydrogen-like atoms with circular orbits is presented. As the derivation requires basic knowledge of classical and relativistic mechanics, it can be taught in standard courses in modern physics and introductory quantum mechanics. In addition, it can be shown in a class that…

  5. Nonlinear optics in relativistic plasmas.

    PubMed

    Umstadter, D; Chen, S Y; Wagner, R; Maksimchuk, A; Sarkisov, G

    1998-03-30

    We review our recent work on the various nonlinear optical processes that occur as an intense laser propagates through a relativistic plasma. These include the experimental observations of electron acceleration driven by laser-wakefield generation, relativistic self-focusing, waveguide formation and laser self-channeling. PMID:19377614

  6. relline: Relativistic line profiles calculation

    NASA Astrophysics Data System (ADS)

    Dauser, Thomas

    2015-05-01

    relline calculates relativistic line profiles; it is compatible with the common X-ray data analysis software XSPEC (ascl:9910.005) and ISIS (ascl:1302.002). The two basic forms are an additive line model (RELLINE) and a convolution model to calculate relativistic smearing (RELCONV).

  7. Relativistic jets in astrophysics

    NASA Astrophysics Data System (ADS)

    Derishev, E. V.; Zheleznyakov, V. V.; Koryagin, S. A.; Kocharovsky, Vl. V.

    The properties of the plasma state of matter are determined by the motion and the electromagnetic emission of the non-bound electrically charged particles --- electrons, positrons, protons and ions. It is not easy to create plasma in a laboratory. However this state is typical for the cosmic conditions --- at the stars and in the interstellar space. The properties of the laboratory as well as the space plasma are investigated at the Institute of Applied Physics of the Russian Academy of Sciences. The research is focused on the mechanisms of generation and propagation of the electromagnetic radiation --- from the radio waves to the gamma-rays --- in the planetary and stellar atmospheres and at the other astrophysical objects. The extreme physical conditions for a plasma are realized near the compact objects like black holes, neutron stars and collapsing nuclei of the massive stars. The plasma could be strongly non-equlibrium and can produce strong electromagnetic fields. Its bulk motion as well as the chaotic motion of the constituting particles can be relativistic, i. e. the motion can achieve velocities close to the speed of light. The relativistic plasma is frequently observed in the form of jets.

  8. A relativistic trolley paradox

    NASA Astrophysics Data System (ADS)

    Matvejev, Vadim N.; Matvejev, Oleg V.; Grøn, Ø.

    2016-06-01

    We present an apparent paradox within the special theory of relativity, involving a trolley with relativistic velocity and its rolling wheels. Two solutions are given, both making clear the physical reality of the Lorentz contraction, and that the distance on the rails between each time a specific point on the rim touches the rail is not equal to 2 π R , where R is the radius of the wheel, but 2 π R / √{ 1 - R 2 Ω 2 / c 2 } , where Ω is the angular velocity of the wheels. In one solution, the wheel radius is constant as the velocity of the trolley increases, and in the other the wheels contract in the radial direction. We also explain two surprising facts. First that the shape of a rolling wheel is elliptical in spite of the fact that the upper part of the wheel moves faster than the lower part, and thus is more Lorentz contracted, and second that a Lorentz contracted wheel with relativistic velocity rolls out a larger distance between two successive touches of a point of the wheel on the rails than the length of a circle with the same radius as the wheels.

  9. Relativistic harmonic oscillator revisited

    SciTech Connect

    Bars, Itzhak

    2009-02-15

    The familiar Fock space commonly used to describe the relativistic harmonic oscillator, for example, as part of string theory, is insufficient to describe all the states of the relativistic oscillator. We find that there are three different vacua leading to three disconnected Fock sectors, all constructed with the same creation-annihilation operators. These have different spacetime geometric properties as well as different algebraic symmetry properties or different quantum numbers. Two of these Fock spaces include negative norm ghosts (as in string theory), while the third one is completely free of ghosts. We discuss a gauge symmetry in a worldline theory approach that supplies appropriate constraints to remove all the ghosts from all Fock sectors of the single oscillator. The resulting ghost-free quantum spectrum in d+1 dimensions is then classified in unitary representations of the Lorentz group SO(d,1). Moreover, all states of the single oscillator put together make up a single infinite dimensional unitary representation of a hidden global symmetry SU(d,1), whose Casimir eigenvalues are computed. Possible applications of these new results in string theory and other areas of physics and mathematics are briefly mentioned.

  10. Relativistic Continuum Shell Model

    NASA Astrophysics Data System (ADS)

    Grineviciute, Janina; Halderson, Dean

    2011-04-01

    The R-matrix formalism of Lane and Thomas has been extended to the relativistic case so that the many-coupled channels problem may be solved for systems in which binary breakup channels satisfy a relative Dirac equation. The formalism was previously applied to the relativistic impulse approximation RIA and now we applied it to Quantum Hadrodynamics QHD in the continuum Tamm-Dancoff approximation TDA with the classical meson fields replaced by one-meson exchange potentials. None of the published QHD parameters provide a decent fit to the 15 N + p elastic cross section. The deficiency is also evident in inability of the QHD parameters with the one meson exchange potentials to reproduce the QHD single particle energies. Results with alternate parameters sets are presented. A. M. Lane and R. G. Thomas, R-Matrix Theory of Nuclear Reactions, Reviews of Modern Physics, 30 (1958) 257

  11. Relativistic positioning systems: Numerical simulations

    NASA Astrophysics Data System (ADS)

    Puchades Colmenero, Neus

    The position of users located on the Earth's surface or near it may be found with the classic positioning systems (CPS). Certain information broadcast by satellites of global navigation systems, as GPS and GALILEO, may be used for positioning. The CPS are based on the Newtonian formalism, although relativistic post-Newtonian corrections are done when they are necessary. This thesis contributes to the development of a different positioning approach, which is fully relativistic from the beginning. In the relativistic positioning systems (RPS), the space-time position of any user (ship, spacecraft, and so on) can be calculated with the help of four satellites, which broadcast their proper times by means of codified electromagnetic signals. In this thesis, we have simulated satellite 4-tuples of the GPS and GALILEO constellations. If a user receives the signals from four satellites simultaneously, the emission proper times read -after decoding- are the user "emission coordinates". In order to find the user "positioning coordinates", in an appropriate almost inertial reference system, there are two possibilities: (a) the explicit relation between positioning and emission coordinates (broadcast by the satellites) is analytically found or (b) numerical codes are designed to calculate the positioning coordinates from the emission ones. Method (a) is only viable in simple ideal cases, whereas (b) allows us to consider realistic situations. In this thesis, we have designed numerical codes with the essential aim of studying two appropriate RPS, which may be generalized. Sometimes, there are two real users placed in different positions, which receive the same proper times from the same satellites; then, we say that there is bifurcation, and additional data are needed to choose the real user position. In this thesis, bifurcation is studied in detail. We have analyzed in depth two RPS models; in both, it is considered that the satellites move in the Schwarzschild's space

  12. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  13. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  14. A numerical investigation of relativistic turbulence

    NASA Astrophysics Data System (ADS)

    Zrake, Jonathan J.

    We present a program of numerical simulations designed to investigate the fundamental properties and phenomenological consequences of relativistic hydrodynamic and magnetohydrodynamic (MHD) turbulence. For the hydrodynamic case, we simulate a relativistically warm gas in a cubic periodic domain continuously driven at large scales with Lorentz factor of about 3. We employ a fifth-order accurate conservative finite-difference scheme on a uniform mesh with resolution up to 20483. The power spectrum of four-velocity scales with the -5/3 power of the wave-number, although deviations from strict scale similarity are evident. A Lorentz-covariant generalization of the longitudinal structure function is introduced, and found to be consistent with existing intermittency models. One-point statistics of the density field Gammarho are approximately log-normal, with skewness toward low densities being well modeled by recent advances in the compressible turbulence literature. Fundamental properties of driven, trans-relativistic, trans-Alfvenic MHD turbulence are studied on uniform meshes up to $10243. Classical predictions from the non-relativistic turbulence literature, such as the scale dependence of anisotropy with respect to the local magnetic field, are verified to hold in trans-relativistic conditions. Detailed studies of the small-scale turbulent dynamo for the conditions of merging neutron star binaries have been conducted. The dynamo is studied at a range of resolutions between 163 and 10243, from the kinematic through non-linear and saturation phases. Good agreement is found with classical predictions of the kinematic phase, and comparisons are made with recent measurements of non-linear dynamo efficiency. We find that very robustly, seed fields are amplified to magnetar strength (4 x1016 Gauss) within the ˜1 ms merger time-scale over 1 km turbulent volumes. The global magnetic energy budget is controlled by the prevalence and vigor of the turbulent volumes, with

  15. On the relativistic and nonrelativistic electron descriptions in high-energy atomic collisions

    NASA Astrophysics Data System (ADS)

    Voitkiv, A. B.

    2007-07-01

    We consider the relativistic and nonrelativistic descriptions of an atomic electron in collisions with point-like charged projectiles moving at relativistic velocities. We discuss three different forms of the fully relativistic first-order transition amplitude. Using the Schrödinger-Pauli equation to describe the atomic electron we establish the correct form of the nonrelativistic first-order transition amplitude. We also show that the so-called semi-relativistic treatment, in which the Darwin states are used to describe the atomic electron, is in fact fully equivalent to the nonrelativistic consideration. The comparison of results obtained with the relativistic and nonrelativistic electron descriptions shows that the latter is accurate within 20-30% up to Za<~ 50-60, where Za is the atomic nuclear charge.

  16. Relativistic astrophysics explorer

    NASA Astrophysics Data System (ADS)

    Kaaret, P.

    2004-01-01

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 6 m 2 equal to 10 times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  17. The Relativistic Astrophysics Explorer

    NASA Astrophysics Data System (ADS)

    Kaaret, P.

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 60,000 cm2 equal to ten times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  18. Relativistic Jets in Collapsars

    NASA Astrophysics Data System (ADS)

    Zhang, Weiqun; Woosley, S. E.; MacFadyen, A. I.

    2003-04-01

    We examine the propagation of two-dimensional relativistic jets through the stellar progenitor in the collapsar model for gamma-ray bursts. In agreement with previous studies, we find that the jet is collimated by its passage. Moreover, interaction of the jet with the star causes mixing that sporadically decelerates the jet, leading to a highly variable Lorentz factor. The jet that finally emerges has a moderate Lorentz factor, but a very large internal energy loading. In a second series of calculations we follow the emergence of such enegy-loaded jets from the star. For the initial conditions chosen, conversion of the remaining internal energy gives a terminal Lorentz factor of approximately 150. Implications of our calculations for GRB light curves, the luminosity-variability relation, and the GRB-supernova association are discussed.

  19. Photodetachment of relativistic ions

    SciTech Connect

    Donahue, J.B.; Gram, P.A.M.; Hamm, M.E.; Hamm, R.W.; Bryant, H.C.; Butterfield, K.B.; Clark, D.A.; Frost, C.A.; Smith, W.W.

    1980-01-01

    A series of fundamental laser ion beam experiments has been made feasible by the high-quality, relativistic (..beta.. = 0.842) H/sup -/ ion beam available at the Clinton P. Anderson Meson Physics Facility (LAMPF). The relatavistic Doppler shift of the light from an ordinary ultraviolet laser provides what is, in effect, a continuously tunable vacuum-ultraviolet laser in the rest frame of the moving ions. The Lorentz transformation of a modest laboratory magnetic field provides an electric field of several megavolts/centimeter. The latest results of photo-detachment work with H/sup -/ beams and our spectroscopic work with H/sup 0/ beams are presented. Plans for future work are discussed.

  20. Relativistic quantum cryptography

    NASA Astrophysics Data System (ADS)

    Molotkov, S. N.; Nazin, S. S.

    2003-07-01

    The problem of unconditional security of quantum cryptography (i.e. the security which is guaranteed by the fundamental laws of nature rather than by technical limitations) is one of the central points in quantum information theory. We propose a relativistic quantum cryptosystem and prove its unconditional security against any eavesdropping attempts. Relativistitic causality arguments allow to demonstrate the security of the system in a simple way. Since the proposed protocol does not empoly collective measurements and quantum codes, the cryptosystem can be experimentally realized with the present state-of-art in fiber optics technologies. The proposed cryptosystem employs only the individual measurements and classical codes and, in addition, the key distribution problem allows to postpone the choice of the state encoding scheme until after the states are already received instead of choosing it before sending the states into the communication channel (i.e. to employ a sort of "antedate" coding).

  1. Relativistic Heavy Ion Collider

    SciTech Connect

    Willen, E.H.

    1986-01-01

    The Relativistic Heavy Ion Collider (RHIC) is a proposed research facility at Brookhaven National Laboratory to study the collision of beams of heavy ions, up to gold in mass and at beam energies up to 100 GeV/nucleon. The physics to be explored by this collider is an overlap between the traditional disciplines of nuclear physics and high energy physics and is a continuation of the planned program of light and heavy ion physics at BNL. The machine is to be constructed in the now-empty tunnel built for the former CBA project. Various other facilities to support the collider are either in place or under construction at BNL. The collider itself, including the magnets, is in an advanced state of design, and a construction start is anticipated in the next several years.

  2. Hydrodynamics of Relativistic Fireballs

    NASA Technical Reports Server (NTRS)

    Piran, Tsvi; Shemi, Amotz; Narayan, Ramesh

    1993-01-01

    Many models of gamma-ray bursts involve a fireball, which is an optically thick concentration of radiation energy with a high ratio of energy density to rest mass. We examine analytically and numerically the evolution of a relativistic fireball. We show that, after an early rearrangement phase, most of the matter and energy in the fireball is concentrated within a narrow shell. The shell propagates at nearly the speed of light, with a frozen radial profile, and according to a simple set of scaling laws. The spectrum of the escaping radiation is harder at early times and softer later on. Depending on the initial energy-to-mass ratio, the final outcome of a fireball is either photons with roughly the initial temperature or ultrarelativistic baryons. In the latter case, the energy could be converted back to gamma-rays via interaction with surrounding material.

  3. Some problems in relativistic thermodynamics

    SciTech Connect

    Veitsman, E. V.

    2007-11-15

    The relativistic equations of state for ideal and real gases, as well as for various interface regions, have been derived. These dependences help to eliminate some controversies in the relativistic thermodynamics based on the special theory of relativity. It is shown, in particular, that the temperature of system whose velocity tends to the velocity of light in vacuum varies in accordance with the Ott law T = T{sub 0}/{radical}1 - v{sup 2}/c{sup 2}. Relativistic dependences for heat and mass transfer, for Ohm's law, and for a viscous flow of a liquid have also been derived.

  4. Relativistic spin effects in the baryon spectrum

    SciTech Connect

    Garcilazo, Humberto

    2005-04-01

    We study the nonstrange baryon spectrum within a three-body theory that treats relativistically both the space and the spin variables. The relativistic effects of the spin are about one order of magnitude smaller than those due to the use of relativistic momentum variables. The relativistic treatment of the spin breaks the degenerancy that is present in the nonrelativistic model and in the model with only relativistic momentum variables.

  5. RADIATION SPECTRAL SYNTHESIS OF RELATIVISTIC FILAMENTATION

    SciTech Connect

    Frederiksen, Jacob Trier; Haugboelle, Troels; Medvedev, Mikhail V.; Nordlund, Ake

    2010-10-10

    Radiation from many astrophysical sources, e.g., gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly compared with source lifetimes. Radiation emitted from these sources is typically associated with nonlinear plasma physics, complex field topologies, and non-thermal particle distributions. In such circumstances, a standard synchrotron paradigm may fail to produce accurate conclusions regarding the underlying physics. Simulating spectral emission and spectral evolution numerically in various relativistic shock scenarios is then the only viable method to determine the detailed physical origin of the emitted spectra. In this Letter, we present synthetic radiation spectra representing the early stage development of the filamentation (streaming) instability of an initially unmagnetized plasma, which is relevant for both collisionless shock formation and reconnection dynamics in relativistic astrophysical outflows as well as for laboratory astrophysics experiments. Results were obtained using a highly efficient in situ diagnostics method, based on detailed particle-in-cell modeling of collisionless plasmas. The synthetic spectra obtained here are compared with those predicted by a semi-analytical model for jitter radiation from the filamentation instability, the latter including self-consistent generated field topologies and particle distributions obtained from the simulations reported upon here. Spectra exhibit dependence on the presence-or the absence-of an inert plasma constituent, when comparing baryonic plasmas (i.e., containing protons) with pair plasmas. The results also illustrate that considerable care should be taken when using lower-dimensional models to obtain information about the astrophysical phenomena generating observed spectra.

  6. Radiation Spectral Synthesis of Relativistic Filamentation

    NASA Astrophysics Data System (ADS)

    Frederiksen, Jacob Trier; Haugbølle, Troels; Medvedev, Mikhail V.; Nordlund, Åke

    2010-10-01

    Radiation from many astrophysical sources, e.g., gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly compared with source lifetimes. Radiation emitted from these sources is typically associated with nonlinear plasma physics, complex field topologies, and non-thermal particle distributions. In such circumstances, a standard synchrotron paradigm may fail to produce accurate conclusions regarding the underlying physics. Simulating spectral emission and spectral evolution numerically in various relativistic shock scenarios is then the only viable method to determine the detailed physical origin of the emitted spectra. In this Letter, we present synthetic radiation spectra representing the early stage development of the filamentation (streaming) instability of an initially unmagnetized plasma, which is relevant for both collisionless shock formation and reconnection dynamics in relativistic astrophysical outflows as well as for laboratory astrophysics experiments. Results were obtained using a highly efficient in situ diagnostics method, based on detailed particle-in-cell modeling of collisionless plasmas. The synthetic spectra obtained here are compared with those predicted by a semi-analytical model for jitter radiation from the filamentation instability, the latter including self-consistent generated field topologies and particle distributions obtained from the simulations reported upon here. Spectra exhibit dependence on the presence—or the absence—of an inert plasma constituent, when comparing baryonic plasmas (i.e., containing protons) with pair plasmas. The results also illustrate that considerable care should be taken when using lower-dimensional models to obtain information about the astrophysical phenomena generating observed spectra.

  7. Modelling of relativistic laser-plasma interactions

    NASA Astrophysics Data System (ADS)

    Berwick, Stuart James

    In order to characterise the propagation and stability of linearly polarised laser pulses of arbitrary intensity interacting with underdense plasma, a one-dimensional, fully relativistic, covariant electron fluid model is derived. As a first step, the model is Lorentz transformed into a frame moving with the group velocity of the laser pulse. A linear instability analysis is undertaken which generates an infinite hierarchy of homogeneous mode-coupling equations describing the decay of the laser pump via stimulated Raman forward scattering (SRFS), stimulated Raman back scattering (SRBS) and the relativistic modulational instability (RMI). SRFS and RMI are seen to merge into a hybrid instability at high intensities (1>1018Wcm-2) and a 6-wave analysis (rather than the conventional 3 or 4-wave) is required to accurately predict growth. Next, an Eulerian fluid code is developed in order to evolve the full non- linear equations. The method of characteristics is used to integrate the electromagnetic wave equation and a predictor-corrector algorithm is used to integrate the equations of continuity and momentum. After testing, this code is used to simulate the propagation and stability of ultra-short (<200fs), 'table-top' and cos2 modulated laser pulses of relativistic intensities in underdense plasma. Comparison is made to the predictions of the dispersion relation and growth rates obtained in each case are reconciled. The spatiotemporal behaviour is discussed with reference to the results of a 3-wave WKB model of the interaction. The importance of seeding mechanisms, pulse shape and relativity on the evolution of the instabilities is also discussed.

  8. Accurate measurement of time

    NASA Astrophysics Data System (ADS)

    Itano, Wayne M.; Ramsey, Norman F.

    1993-07-01

    The paper discusses current methods for accurate measurements of time by conventional atomic clocks, with particular attention given to the principles of operation of atomic-beam frequency standards, atomic hydrogen masers, and atomic fountain and to the potential use of strings of trapped mercury ions as a time device more stable than conventional atomic clocks. The areas of application of the ultraprecise and ultrastable time-measuring devices that tax the capacity of modern atomic clocks include radio astronomy and tests of relativity. The paper also discusses practical applications of ultraprecise clocks, such as navigation of space vehicles and pinpointing the exact position of ships and other objects on earth using the GPS.

  9. Relativistic Transformation of Solid Angle.

    ERIC Educational Resources Information Center

    McKinley, John M.

    1980-01-01

    Rederives the relativistic transformations of light intensity from compact sources (stars) to show where and how the transformation of a solid angle contributes. Discusses astrophysical and other applications of the transformations. (Author/CS)

  10. Simulating relativistic binaries with Whisky

    NASA Astrophysics Data System (ADS)

    Baiotti, L.

    We report about our first tests and results in simulating the last phase of the coalescence and the merger of binary relativistic stars. The simulations were performed using our code Whisky and mesh refinement through the Carpet driver.

  11. Conductivity of a relativistic plasma

    SciTech Connect

    Braams, B.J.; Karney, C.F.F.

    1989-03-01

    The collision operator for a relativistic plasma is reformulated in terms of an expansion in spherical harmonics. This formulation is used to calculate the electrical conductivity. 13 refs., 1 fig., 1 tab.

  12. Atomic electron energies including relativistic effects and quantum electrodynamic corrections

    NASA Technical Reports Server (NTRS)

    Aoyagi, M.; Chen, M. H.; Crasemann, B.; Huang, K. N.; Mark, H.

    1977-01-01

    Atomic electron energies have been calculated relativistically. Hartree-Fock-Slater wave functions served as zeroth-order eigenfunctions to compute the expectation of the total Hamiltonian. A first order correction to the local approximation was thus included. Quantum-electrodynamic corrections were made. For all orbitals in all atoms with 2 less than or equal to Z less than or equal to 106, the following quantities are listed: total energies, electron kinetic energies, electron-nucleus potential energies, electron-electron potential energies consisting of electrostatic and Breit interaction (magnetic and retardation) terms, and vacuum polarization energies. These results will serve for detailed comparison of calculations based on other approaches. The magnitude of quantum electrodynamic corrections is exhibited quantitatively for each state.

  13. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  14. Interference in multilayer relativistic mirrors

    NASA Astrophysics Data System (ADS)

    Mirzanejhad, Saeed; Sohbatzadeh, Farshad; Babaei, Javad; Taghipour, Meisam; Mohammadzadeh, Zahra

    2015-10-01

    In this paper, reflection coefficient of a relativistic ultra-thin electron multilayer is calculated using electromagnetic interference procedures. The relativistic electron layers are assumed to be formed by nonlinear plasma wake waves that constitute the electron density cusps. It is shown that the interference between successive relativistic mirrors is restricted by the condition, τ p ≫ ( 2 γ 0 ) 5 / 2 / ω p 0 , where τp is the laser pulse duration. The results showed that tailoring the pulse amplitude, incident wave frequency value, incidence angle, and plasma density leads to increasing reflection coefficient a few orders of magnitudes. This constructive interference condition can be used for increasing conversion efficiency in the reflected energy from relativistic mirrors for the purpose of generating ultra-short coherence pulses in the extreme ultraviolet and x-ray regions. We also performed reflection from relativistic thin electron layers using relativistic 1D3V electromagnetic particle-in-cell (PIC) simulation. It was found that the results of PIC simulation are in agreement with analytical considerations.

  15. Relativistic magnetohydrodynamics in one dimension.

    PubMed

    Lyutikov, Maxim; Hadden, Samuel

    2012-02-01

    We derive a number of solutions for one-dimensional dynamics of relativistic magnetized plasma that can be used as benchmark estimates in relativistic hydrodynamic and magnetohydrodynamic numerical codes. First, we analyze the properties of simple waves of fast modes propagating orthogonally to the magnetic field in relativistically hot plasma. The magnetic and kinetic pressures obey different equations of state, so that the system behaves as a mixture of gases with different polytropic indices. We find the self-similar solutions for the expansion of hot strongly magnetized plasma into vacuum. Second, we derive linear hodograph and Darboux equations for the relativistic Khalatnikov potential, which describe arbitrary one-dimensional isentropic relativistic motion of cold magnetized plasma and find their general and particular solutions. The obtained hodograph and Darboux equations are very powerful: A system of highly nonlinear, relativistic, time-dependent equations describing arbitrary (not necessarily self-similar) dynamics of highly magnetized plasma reduces to a single linear differential equation. PMID:22463331

  16. Causal localizations in relativistic quantum mechanics

    SciTech Connect

    Castrigiano, Domenico P. L. Leiseifer, Andreas D.

    2015-07-15

    Causal localizations describe the position of quantum systems moving not faster than light. They are constructed for the systems with finite spinor dimension. At the center of interest are the massive relativistic systems. For every positive mass, there is the sequence of Dirac tensor-localizations, which provides a complete set of inequivalent irreducible causal localizations. They obey the principle of special relativity and are fully Poincaré covariant. The boosters are determined by the causal position operator and the other Poincaré generators. The localization with minimal spinor dimension is the Dirac localization. Thus, the Dirac equation is derived here as a mere consequence of the principle of causality. Moreover, the higher tensor-localizations, not known so far, follow from Dirac’s localization by a simple construction. The probability of localization for positive energy states results to be described by causal positive operator valued (PO-) localizations, which are the traces of the causal localizations on the subspaces of positive energy. These causal Poincaré covariant PO-localizations for every irreducible massive relativistic system were, all the more, not known before. They are shown to be separated. Hence, the positive energy systems can be localized within every open region by a suitable preparation as accurately as desired. Finally, the attempt is made to provide an interpretation of the PO-localization operators within the frame of conventional quantum mechanics attributing an important role to the negative energy states.

  17. Relativistic theory of gravitation

    SciTech Connect

    Logunov, A.A.; Mestvirishvili, M.A.

    1986-01-01

    In the present paper a relativistic theory of gravitation (RTG) is unambiguously constructed on the basis of the special relativity and geometrization principle. In this a gravitational field is treated as the Faraday--Maxwell spin-2 and spin-0 physical field possessing energy and momentum. The source of a gravitational field is the total conserved energy-momentum tensor of matter and of a gravitational field in Minkowski space. In the RTG the conservation laws are strictly fulfilled for the energy-moment and for the angular momentum of matter and a gravitational field. The theory explains the whole available set of experiments on gravity. By virtue of the geometrization principle, the Riemannian space in our theory is of field origin, since it appears as an effective force space due to the action of a gravitational field on matter. The RTG leads to an exceptionally strong prediction: The universe is not closed but just ''flat.'' This suggests that in the universe a ''missing mass'' should exist in a form of matter.

  18. Rarefaction wave in relativistic steady magnetohydrodynamic flows

    SciTech Connect

    Sapountzis, Konstantinos Vlahakis, Nektarios

    2014-07-15

    We construct and analyze a model of the relativistic steady-state magnetohydrodynamic rarefaction that is induced when a planar symmetric flow (with one ignorable Cartesian coordinate) propagates under a steep drop of the external pressure profile. Using the method of self-similarity, we derive a system of ordinary differential equations that describe the flow dynamics. In the specific limit of an initially homogeneous flow, we also provide analytical results and accurate scaling laws. We consider that limit as a generalization of the previous Newtonian and hydrodynamic solutions already present in the literature. The model includes magnetic field and bulk flow speed having all components, whose role is explored with a parametric study.

  19. Relativistic corrections to the nuclear Schiff moment

    SciTech Connect

    Dmitriev, V.F.; Flambaum, V.V.

    2005-06-01

    Parity- and time-invariance-violating (P,T-odd) atomic electric dipole moments (EDM) are induced by the interaction between atomic electrons and nuclear P,T-odd moments, which are themselves produced by P,T-odd nuclear forces. The nuclear EDM is screened by atomic electrons. The EDM of a nonrelativistic atom with closed electron subshells is induced by the nuclear Schiff moment. For heavy relativistic atoms EDM is induced by the nuclear local dipole moments, which differ by 10-50% from the Schiff moments calculated previously. We calculate the local dipole moments for {sup 199}Hg and {sup 205}Tl where the most accurate atomic [Romalis et al., Phys. Rev. Lett. 86, 2505 (2001)] and molecular [Cho et al., Phys. Rev. Lett. 63, 2559 (1989); Phys. Rev. A 44, 2783 (1991)] EDM measurements have been performed.

  20. Reanalysis of relativistic electron phase space density

    NASA Astrophysics Data System (ADS)

    Shprits, Yuri; Chen, Yue; Kondrashov, Dmitri

    In this study we perform a reanalysis of the sparse relativistic electron data using a relatively simple one-dimensional radial diffusion model and a Kalman filtering approach. The results of the reanalysis clearly show pronounced peaks in the electron phase space density (PSD), which can not be explained by the variations in the outer boundary, and can only be produced by a local acceleration processes. The location of the innovation vector shows that local acceleration is most efficient at L* = 5.5. To verify that our results are not affected by the limitations of the satellite orbit and coverage, we performed an "identical twin" experiments with synthetic data specified only at the locations for which CRRES observations are available. Our results indicate that the model with data assimilation can accurately reproduce the underlying structure of the PSD even when data is sparse.

  1. Refining a relativistic, hydrodynamic solver: Admitting ultra-relativistic flows

    NASA Astrophysics Data System (ADS)

    Bernstein, J. P.; Hughes, P. A.

    2009-09-01

    We have undertaken the simulation of hydrodynamic flows with bulk Lorentz factors in the range 102-106. We discuss the application of an existing relativistic, hydrodynamic primitive variable recovery algorithm to a study of pulsar winds, and, in particular, the refinement made to admit such ultra-relativistic flows. We show that an iterative quartic root finder breaks down for Lorentz factors above 102 and employ an analytic root finder as a solution. We find that the former, which is known to be robust for Lorentz factors up to at least 50, offers a 24% speed advantage. We demonstrate the existence of a simple diagnostic allowing for a hybrid primitives recovery algorithm that includes an automatic, real-time toggle between the iterative and analytical methods. We further determine the accuracy of the iterative and hybrid algorithms for a comprehensive selection of input parameters and demonstrate the latter’s capability to elucidate the internal structure of ultra-relativistic plasmas. In particular, we discuss simulations showing that the interaction of a light, ultra-relativistic pulsar wind with a slow, dense ambient medium can give rise to asymmetry reminiscent of the Guitar nebula leading to the formation of a relativistic backflow harboring a series of internal shockwaves. The shockwaves provide thermalized energy that is available for the continued inflation of the PWN bubble. In turn, the bubble enhances the asymmetry, thereby providing positive feedback to the backflow.

  2. Relativistic dynamical collapse model

    NASA Astrophysics Data System (ADS)

    Pearle, Philip

    2015-05-01

    A model is discussed where all operators are constructed from a quantum scalar field whose energy spectrum takes on all real values. The Schrödinger picture wave function depends upon space and time coordinates for each particle, as well as an inexorably increasing evolution parameter s which labels a foliation of spacelike hypersurfaces. The model is constructed to be manifestly Lorentz invariant in the interaction picture. Free particle states and interactions are discussed in this framework. Then, the formalism of the continuous spontaneous localization (CSL) theory of dynamical collapse is applied. The collapse-generating operator is chosen to be the particle number space-time density. Unlike previous relativistically invariant models, the vacuum state is not excited. The collapse dynamics depends upon two parameters, a parameter Λ which represents the collapse rate/volume and a scale factor ℓ. A common example of collapse dynamics, involving a clump of matter in a superposition of two locations, is analyzed. The collapse rate is shown to be identical to that of nonrelativistic CSL when the GRW-CSL choice of ℓ=a =1 0-5 cm , is made, along with Λ =λ /a3 (GRW-CSL choice λ =1 0-16s-1). The collapse rate is also satisfactory with the choice ℓ as the size of the Universe, with Λ =λ /ℓa2. Because the collapse narrows wave functions in space and time, it increases a particle's momentum and energy, altering its mass. It is shown that, with ℓ=a , the change of mass of a nucleon is unacceptably large but, when ℓ is the size of the Universe, the change of mass over the age of the Universe is acceptably small.

  3. Relativistic breakdown in planetary atmospheres

    SciTech Connect

    Dwyer, J. R.

    2007-04-15

    In 2003, a new electrical breakdown mechanism involving the production of runaway avalanches by positive feedback from runaway positrons and energetic photons was introduced. This mechanism, which shall be referred to as 'relativistic feedback', allows runaway discharges in gases to become self-sustaining, dramatically increasing the flux of runaway electrons, the accompanying high-energy radiation, and resulting ionization. Using detailed Monte Carlo calculations, properties of relativistic feedback are investigated. It is found that once relativistic feedback fully commences, electrical breakdown will occur and the ambient electric field, extending over cubic kilometers, will be discharged in as little as 2x10{sup -5} s. Furthermore, it is found that the flux of energetic electrons and x rays generated by this mechanism can exceed the flux generated by the standard relativistic runaway electron model by a factor of 10{sup 13}, making relativistic feedback a good candidate for explaining terrestrial gamma-ray flashes and other high-energy phenomena observed in the Earth's atmosphere.

  4. Theory of relativistic cyclotron masers

    NASA Astrophysics Data System (ADS)

    Nusinovich, G. S.; Latham, P. E.; Dumbrajs, O.

    1995-07-01

    In this paper we have made an attempt to review the present status of the theory of cyclotron masers with relativistic electron beams. After discussing the basic features of electron-cyclotron radiation under conditions of normal and anomalous Doppler frequency shifts, we consider particle deceleration by a constant amplitude electromagnetic wave in a constant magnetic field using the formalism developed earlier for cyclotron autoresonance acceleration of electrons. An optimal cyclotron resonance mismatch was found that corresponds to the possibility of complete deceleration of relativistic electrons. Then, interaction of relativistic electrons with resonator fields is considered and the efficiency increase due to electron prebunching is demonstrated in a simple model. Since an efficient interaction of relativistic electrons with the large amplitude electromagnetic field of a resonator occurs at a short distance, where electrons make a small number of electron orbits, the issue of the simultaneous interaction of electrons with the field at several cyclotron harmonics is discussed. Finally, we consider deceleration of a prebunched electron beam by a traveling electromagnetic wave in a tapered magnetic field. This simple modeling is illustrated with a number of simulations of relativistic gyroklystrons and gyrotwistrons (gyrodevices in which the bunching cavity of the gyroklystron is combined with the output waveguide of the gyro-traveling-wave-tube).

  5. A relativistic calculation of the deuteron threshold electrodisintegration at backward angles

    SciTech Connect

    Schiavilla, Rocco

    2007-07-01

    The threshold electrodisintegration of the deuteron at backward angles is studied with a relativistic Hamiltonian, including a relativistic one-pion-exchange potential (OPEP) with off-shell terms as predicted by pseudovector coupling of pions to nucleons. The bound and scattering states are obtained in the center-of-mass frame, and then boosted from it to the Breit frame, where the evaluation of the relevant matrix elements of the electromagnetic current operator is carried out. The latter includes, in addition to one-body, also two-body terms due to pion exchange, as obtained, consistently with the OPEP, in pseudovector pion-nucleon coupling theory. The full Lorentz structure of these currents is retained. In order to estimate the magnitude of the relativistic effects we perform, for comparison, the calculation with a non-relativistic phase-equivalent Hamiltonian and the standard non-relativistic expressions for the one-body and two-body pion-exchange currents. Our results for the electrodisintegration cross section show that, in the calculations using one-body currents, relativistic corrections become significant (i.e., larger than 10%) only at high momentum transfer Q (Q2 ~ 40fm-2 and beyond). However, the inclusion of two-body currents makes the relativistic predictions considerably smaller than the corresponding non-relativistic results in the Q2 region (18-40) fm-2. The calculations based on the relativistic model also confirm the inadequacy, already established in a non-relativistic context, of the present electromagnetic current model to reproduce accurately the experimental data at intermediate values of momentum transfers.

  6. Particle Acceleration at Relativistic and Ultra-Relativistic Shock Waves

    NASA Astrophysics Data System (ADS)

    Meli, A.

    We perform Monte Carlo simulations using diffusive shock acceleration at relativistic and ultra-relativistic shock waves. High upstream flow gamma factors are used, Γ=(1-uup2/c2)-0.5, which are relevant to models of ultra-relativistic particle shock acceleration in the central engines and relativistic jets of Active Galactic Nuclei (AGN) and in Gamma-Ray Burst (GRB) fireballs. Numerical investigations are carried out on acceleration properties in the relativistic and ultra-relativistic flow regime (Γ ˜ 10-1000) concerning angular distributions, acceleration time scales, particle energy gain versus number of crossings and spectral shapes. We perform calculations for both parallel and oblique sub-luminal and super-luminal shocks. For parallel and oblique sub-luminal shocks, the spectra depend on whether or not the scattering is represented by pitch angle diffusion or by large angle scattering. The large angle case exhibits a distinctive structure in the basic power-law spectrum not nearly so obvious for small angle scattering. However, both cases yield a significant 'speed-up' of acceleration rate when compared with the conventional, non-relativistic expression, tacc=[c/(uup-udown)] (λup/uup+λdown/udown). An energization by a factor Γ2 for the first crossing cycle and a large energy gains for subsequent crossings as well as the high 'speed-up' factors found, are important in supporting past works, especially the models developed by Vietri and Waxman on ultra-high energy cosmic ray, neutrino and gamma-ray production in GRB. For oblique super-luminal shocks, we calculate the energy gain and spectral shape for a number of different inclinations. For this case the acceleration of particles is 'pictured' by a shock drift mechanism. We use high gamma flows with Lorentz factors in the range 10-40 which are relevant to ultra-relativistic shocks in AGN accretion disks and jets. In all investigations we closely follow the particle's trajectory along the magnetic field

  7. Fluctuations in relativistic causal hydrodynamics

    NASA Astrophysics Data System (ADS)

    Kumar, Avdhesh; Bhatt, Jitesh R.; Mishra, Ananta P.

    2014-05-01

    Formalism to calculate the hydrodynamic fluctuations by applying the Onsager theory to the relativistic Navier-Stokes equation is already known. In this work, we calculate hydrodynamic fluctuations within the framework of the second order hydrodynamics of Müller, Israel and Stewart and its generalization to the third order. We have also calculated the fluctuations for several other causal hydrodynamical equations. We show that the form for the Onsager-coefficients and form of the correlation functions remain the same as those obtained by the relativistic Navier-Stokes equation and do not depend on any specific model of hydrodynamics. Further we numerically investigate evolution of the correlation function using the one dimensional boost-invariant (Bjorken) flow. We compare the correlation functions obtained using the causal hydrodynamics with the correlation function for the relativistic Navier-Stokes equation. We find that the qualitative behavior of the correlation functions remains the same for all the models of the causal hydrodynamics.

  8. Non-Relativistic Superstring Theories

    SciTech Connect

    Kim, Bom Soo

    2007-12-14

    We construct a supersymmetric version of the 'critical' non-relativistic bosonic string theory [1] with its manifest global symmetry. We introduce the anticommuting bc CFT which is the super partner of the {beta}{gamma} CFT. The conformal weights of the b and c fields are both 1/2. The action of the fermionic sector can be transformed into that of the relativistic superstring theory. We explicitly quantize the theory with manifest SO(8) symmetry and find that the spectrum is similar to that of Type IIB superstring theory. There is one notable difference: the fermions are non-chiral. We further consider 'noncritical' generalizations of the supersymmetric theory using the superspace formulation. There is an infinite range of possible string theories similar to the supercritical string theories. We comment on the connection between the critical non-relativistic string theory and the lightlike Linear Dilaton theory.

  9. Polyanalytic relativistic second Bargmann transforms

    SciTech Connect

    Mouayn, Zouhaïr

    2015-05-15

    We construct coherent states through special superpositions of eigenstates of the relativistic isotonic oscillator. In each superposition, the coefficients are chosen to be L{sup 2}-eigenfunctions of a σ-weight Maass Laplacian on the Poincaré disk, which are associated with the eigenvalue 4m(σ−1−m), m∈Z{sub +}∩[0,(σ−1)/2]. For each nonzero m, the associated coherent states transform constitutes the m-true-polyanalytic extension of a relativistic version of the second Bargmann transform, whose integral kernel is expressed in terms of a special Appel-Kampé de Fériet’s hypergeometric function. The obtained results could be used to extend the known semi-classical analysis of quantum dynamics of the relativistic isotonic oscillator.

  10. Ion Acceleration Using Relativistic Pulse Shaping in Near-Critical-Density Plasmas.

    PubMed

    Bin, J H; Ma, W J; Wang, H Y; Streeter, M J V; Kreuzer, C; Kiefer, D; Yeung, M; Cousens, S; Foster, P S; Dromey, B; Yan, X Q; Ramis, R; Meyer-ter-Vehn, J; Zepf, M; Schreiber, J

    2015-08-01

    Ultraintense laser pulses with a few-cycle rising edge are ideally suited to accelerating ions from ultrathin foils, and achieving such pulses in practice represents a formidable challenge. We show that such pulses can be obtained using sufficiently strong and well-controlled relativistic nonlinearities in spatially well-defined near-critical-density plasmas. The resulting ultraintense pulses with an extremely steep rising edge give rise to significantly enhanced carbon ion energies consistent with a transition to radiation pressure acceleration. PMID:26296119

  11. (Relativistic heavy ion research)

    SciTech Connect

    Not Available

    1990-01-01

    At Brookhaven National Laboratory, participation in the E802 Experiment, which is the first major heavy-ion experiment at the BNL-AGS, was the main focus of the group during the past four years. The emphases of the E802 experiment were on (a) accurate particle identification and measurements of spectra over a wide kinematical domain (5{degree} < {theta}{sub LAB} < 55{degree}, p < 20 GeV/c); and (b) measurements of small-angle two-particle correlations, with event characterization tools: multiplicity array, forward and large-angle calorimeters. This experiment and other heavy ion collision experiments are discussed in this report.

  12. Phenomenological Relativistic Energy Density Functionals

    SciTech Connect

    Lalazissis, G. A.; Kartzikos, S.; Niksic, T.; Paar, N.; Vretenar, D.; Ring, P.

    2009-08-26

    The framework of relativistic nuclear energy density functionals is applied to the description of a variety of nuclear structure phenomena, not only in spherical and deformed nuclei along the valley of beta-stability, but also in exotic systems with extreme isospin values and close to the particle drip-lines. Dynamical aspects of exotic nuclear structure is explored using the fully consistent quasiparticle random-phase approximation based on the relativistic Hartree-Bogoliubov model. Recent applications of energy density functionals with explicit density dependence of the meson-nucleon couplings are presented.

  13. Theory of the relativistic gyrotwistron

    NASA Astrophysics Data System (ADS)

    Nusinovich, G. S.; Li, H.

    1992-04-01

    A generalized theory of the relativistic gyrotwistron, the device combining the elements of the gyroklystron and the gyro-traveling wave tube, is presented. A modulation of electrons in the input cavity is considered with the account of modulation in an electron axial momentum that is important for relativistic particles passing through a short cavity. A comprehensive study of large-signal operation of the output waveguide section in the cases of gyroresonance at the fundamental and second cyclotron harmonics has demonstrated a wide variety of electron bunching phenomena and the possibility of achieving high electron efficiency in a wide range of gyrotwistron parameters.

  14. Relativistic Hydrodynamics for Heavy-Ion Collisions

    ERIC Educational Resources Information Center

    Ollitrault, Jean-Yves

    2008-01-01

    Relativistic hydrodynamics is essential to our current understanding of nucleus-nucleus collisions at ultrarelativistic energies (current experiments at the Relativistic Heavy Ion Collider, forthcoming experiments at the CERN Large Hadron Collider). This is an introduction to relativistic hydrodynamics for graduate students. It includes a detailed…

  15. Relativistic treatment of inertial spin effects

    NASA Astrophysics Data System (ADS)

    Ryder, Lewis

    1998-03-01

    A relativistic spin operator for Dirac particles is identified and it is shown that a coupling of spin to angular velocity arises in the relativistic case, just as Mashhoon had speculated, and Hehl and Ni had demonstrated, in the non-relativistic case.

  16. Relativistic Positioning System in perturbed spacetime

    NASA Astrophysics Data System (ADS)

    Kostić, Uroš; Horvat, Martin; Gomboc, Andreja

    2015-11-01

    We present a variant of a Global Navigation Satellite System called a Relativistic Positioning System (RPS), which is based on emission coordinates. We modelled the RPS dynamics in a spacetime around Earth, described by a perturbed Schwarzschild metric, where we included the perturbations due to Earth multipoles (up to the 6th), the Moon, the Sun, Venus, Jupiter, solid tide, ocean tide, and Kerr rotation effect. The exchange of signals between the satellites and a user was calculated using a ray-tracing method in the Schwarzschild spacetime. We find that positioning in a perturbed spacetime is feasible and is highly accurate already with standard numerical procedures: the positioning algorithms used to transform between the emission and the Schwarzschild coordinates of the user are very accurate and time efficient—on a laptop it takes 0.04 s to determine the user’s spatial and time coordinates with a relative accuracy of {10}-28-{10}-26 and {10}-32-{10}-30, respectively.

  17. Relativistic Transverse Gravitational Redshift

    NASA Astrophysics Data System (ADS)

    Mayer, A. F.

    2012-12-01

    symmetric energy potential exists between the frames that is quantified by the instantaneous Δ {v} = v\\cdot{d}φ between them; in order for either frame to become indistinguishable from the other, such that their respective velocity and acceleration vectors are parallel, a change in velocity is required. While the qualitative features of general relativity imply this phenomenon (i.e., a symmetric potential difference between two points on a Newtonian `equipotential surface' that is similar to a friction effect), it is not predicted by the field equations due to a modeling error concerning time. This is an error of omission; time has fundamental geometric properties implied by the principles of relativity that are not reflected in the field equations. Where b is the radius and g is the gravitational acceleration characterizing a spherical geoid S of an ideal point-source gravitational field, an elegant derivation that rests on first principles shows that for two points at rest on S separated by a distance d << b, a symmetric relativistic redshift exists between these points of magnitude z = gd2/bc^2, which over 1 km at Earth sea level yields z ˜{10-17}. It can be tested with a variety of methods, in particular laser interferometry. A more sophisticated derivation yields a considerably more complex predictive formula for any two points in a gravitational field.

  18. The Scalar Relativistic Contribution to Ga-Halide Bond Energies

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Arnold, James O. (Technical Monitor)

    1998-01-01

    The one-electron Douglas Kroll (DK) and perturbation theory (+R) approaches are used to compute the scalar relativistic contribution to the atomization energies of GaFn. These results are compared with the previous GaCln results. While the +R and DK results agree well for the GaCln atom nation energies, they differ for GaFn. The present work suggests that the DK approach is more accurate than the +R approach. In addition, the DK approach is less sensitive to the choice of basis set. The computed atomization energies of GaF2 and GaF3 are smaller than the somewhat uncertain experiments. It is suggested that additional calibration calculations for the scalar relativistic effects in GaF2 and GaF3 would be valuable.

  19. Relativistic electromagnetic waves in an electron-ion plasma

    NASA Technical Reports Server (NTRS)

    Chian, Abraham C.-L.; Kennel, Charles F.

    1987-01-01

    High power laser beams can drive plasma particles to relativistic energies. An accurate description of strong waves requires the inclusion of ion dynamics in the analysis. The equations governing the propagation of relativistic electromagnetic waves in a cold electron-ion plasma can be reduced to two equations expressing conservation of energy-momentum of the system. The two conservation constants are functions of the plasma stream velocity, the wave velocity, the wave amplitude, and the electron-ion mass ratio. The dynamic parameter, expressing electron-ion momentum conversation in the laboratory frame, can be regarded as an adjustable quantity, a suitable choice of which will yield self-consistent solutions when other plasma parameters were specified. Circularly polarized electromagnetic waves and electrostatic plasma waves are used as illustrations.

  20. The Highest Redshift Relativistic Jets

    SciTech Connect

    Cheung, C.C.; Stawarz, L.; Siemiginowska, A.; Harris, D.E; Schwartz, D.A.; Wardle, J.F.C.; Gobeille, D.; Lee, N.P.

    2007-12-18

    We describe our efforts to understand large-scale (10's-100's kpc) relativistic jet systems through observations of the highest-redshift quasars. Results from a VLA survey search for radio jets in {approx} 30 z > 3.4 quasars are described along with new Chandra observations of 4 selected targets.

  1. Proper-time relativistic dynamics

    NASA Technical Reports Server (NTRS)

    Gill, Tepper L.; Zachary, W. W.; Lindesay, James

    1993-01-01

    Proper-time relativistic single-particle classical Hamiltonian mechanics is formulated using a transformation from observer time to system proper time which is a canonical contact transformation on extended phase space. It is shown that interaction induces a change in the symmetry structure of the system which can be analyzed in terms of a Lie-isotopic deformation of the algebra of observables.

  2. Future relativistic heavy ion experiments

    SciTech Connect

    Pugh, H.G.

    1980-12-01

    Equations of state for nuclear matter and ongoing experimental studies are discussed. Relativistic heavy ion physics is the only opportunity to study in the laboratory the properties of extended multiquark systems under conditions such that quarks might run together into new arrangements previously unobserved. Several lines of further study are mentioned. (GHT)

  3. Particle Acceleration in Relativistic Outflows

    NASA Technical Reports Server (NTRS)

    Bykov, Andrei; Gehrels, Neil; Krawczynski, Henric; Lemoine, Martin; Pelletier, Guy; Pohl, Martin

    2012-01-01

    In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.

  4. BOOK REVIEW: Relativistic Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Antoine, J.-P.

    2004-01-01

    The aim of relativistic quantum mechanics is to describe the finer details of the structure of atoms and molecules, where relativistic effects become nonnegligible. It is a sort of intermediate realm, between the familiar nonrelativistic quantum mechanics and fully relativistic quantum field theory, and thus it lacks the simplicity and elegance of both. Yet it is a necessary tool, mostly for quantum chemists. Pilkuhn's book offers to this audience an up-to-date survey of these methods, which is quite welcome since most previous textbooks are at least ten years old. The point of view of the author is to start immediately in the relativistic domain, following the lead of Maxwell's equations rather than classical mechanics, and thus to treat the nonrelativistic version as an approximation. Thus Chapter 1 takes off from Maxwell's equations (in the noncovariant Coulomb gauge) and gradually derives the basic aspects of Quantum Mechanics in a rather pedestrian way (states and observables, Hilbert space, operators, quantum measurement, scattering,. Chapter 2 starts with the Lorentz transformations, then continues with the Pauli spin equation and the Dirac equation and some of their applications (notably the hydrogen atom). Chapter 3 is entitled `Quantum fields and particles', but falls short of treating quantum field theory properly: only creation/annihilation operators are considered, for a particle in a box. The emphasis is on two-electron states (the Pauli principle, the Foldy--Wouthuysen elimination of small components of Dirac spinors, Breit projection operators. Chapter 4 is devoted to scattering theory and the description of relativistic bound states. Chapter 5, finally, covers hyperfine interactions and radiative corrections. As we said above, relativistic quantum mechanics is by nature limited in scope and rather inelegant and Pilkuhn's book is no exception. The notation is often heavy (mostly noncovariant) and the mathematical level rather low. The central topic

  5. Low-momentum-transfer nonrelativistic limit of the relativistic impulse approximation expression for Compton-scattering doubly differential cross sections and characterization of their relativistic contributions

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.

    2010-04-01

    The nonrelativistic (nr) impulse approximation (NRIA) expression for Compton-scattering doubly differential cross sections (DDCS) for inelastic photon scattering is recovered from the corresponding relativistic expression (RIA) of Ribberfors [Phys. Rev. B 12, 2067 (1975)] in the limit of low momentum transfer (q→0), valid even at relativistic incident photon energies ω1>m provided that the average initial momentum of the ejected electron is not too high, that is, accurate Compton peak (CP) even when ω1>m using nr expressions when θ is small. For example, a 1% accuracy can be obtained when ω1=1MeV if θ<20°. However as ω1 increases into the MeV range, the maximum θ at which an accurate Compton peak can be obtained from nr expressions approaches closer to zero, because the θ at which the relativistic shift of CP to higher energy is greatest, which starts at 180° when ω1<300 keV, begins to decrease, approaching zero even though the θ at which the relativistic increase in the CP magnitude remains greatest around θ=180°. The relativistic contribution to the prediction of Compton doubly differential cross sections (DDCS) is characterized in simple terms using Ribberfors further approximation to his full RIA expression. This factorable form is given by DDCS=KJ, where K is the kinematic factor and J the Compton profile. This form makes it possible to account for the relativistic shift of CP to higher energy and the increase in the CP magnitude as being due to the dependence of J(pmin,ρrel) (where pmin is the relativistic version of the z component of the momentum of the initial electron and ρrel is the relativistic charge density) and K(pmin) on pmin. This characterization approach was used as a guide

  6. Low-momentum-transfer nonrelativistic limit of the relativistic impulse approximation expression for Compton-scattering doubly differential cross sections and characterization of their relativistic contributions

    SciTech Connect

    LaJohn, L. A.

    2010-04-15

    The nonrelativistic (nr) impulse approximation (NRIA) expression for Compton-scattering doubly differential cross sections (DDCS) for inelastic photon scattering is recovered from the corresponding relativistic expression (RIA) of Ribberfors [Phys. Rev. B 12, 2067 (1975)] in the limit of low momentum transfer (q{yields}0), valid even at relativistic incident photon energies {omega}{sub 1}>m provided that the average initial momentum of the ejected electron is not too high, that is, accurate Compton peak (CP) even when {omega}{sub 1}>m using nr expressions when {theta} is small. For example, a 1% accuracy can be obtained when {omega}{sub 1}=1 MeV if {theta}<20 deg. However as {omega}{sub 1} increases into the MeV range, the maximum {theta} at which an accurate Compton peak can be obtained from nr expressions approaches closer to zero, because the {theta} at which the relativistic shift of CP to higher energy is greatest, which starts at 180 deg. when {omega}{sub 1}<300 keV, begins to decrease, approaching zero even though the {theta} at which the relativistic increase in the CP magnitude remains greatest around {theta}=180 deg. The relativistic contribution to the prediction of Compton doubly differential cross sections (DDCS) is characterized in simple terms using Ribberfors further approximation to his full RIA expression. This factorable form is given by DDCS=KJ, where K is the kinematic factor and J the Compton profile. This form makes it possible to account for the relativistic shift of CP to higher energy and the increase in the CP magnitude as being due to the dependence of J(p{sub min},{rho}{sub rel}) (where p{sub min} is the relativistic version of the z

  7. Fast Lattice Boltzmann Solver for Relativistic Hydrodynamics

    SciTech Connect

    Mendoza, M.; Herrmann, H. J.; Boghosian, B. M.; Succi, S.

    2010-07-02

    A lattice Boltzmann formulation for relativistic fluids is presented and numerically validated through quantitative comparison with recent hydrodynamic simulations of relativistic fluids. In order to illustrate its capability to handle complex geometries, the scheme is also applied to the case of a three-dimensional relativistic shock wave, generated by a supernova explosion, impacting on a massive interstellar cloud. This formulation opens up the possibility of exporting the proven advantages of lattice Boltzmann methods, namely, computational efficiency and easy handling of complex geometries, to the context of (mildly) relativistic fluid dynamics at large, from quark-gluon plasmas up to supernovae with relativistic outflows.

  8. Relativistic formulation of the Voigt profile

    NASA Astrophysics Data System (ADS)

    Wcisło, P.; Amodio, P.; Ciuryło, R.; Gianfrani, L.

    2015-02-01

    The relativistic formulation of the Voigt profile is reported for the spontaneous emission from an atomic or molecular cloud, in coincidence with a given spectral line. We considered the simultaneous occurrence of homogeneous broadening and thermal broadening, this latter being determined by the relativistic Doppler effect. Our formula for the relativistic Voigt profile reproduces those characterizing the two available limit cases, namely, the relativistic Gaussian profile and the classical Voigt convolution. The relativistic deformation of the Voigt profile was carefully quantified at different temperatures, in the case of the molecular hydrogen spectrum.

  9. Simulations of Relativistic Extragalactic Jets

    NASA Astrophysics Data System (ADS)

    Hughes, P. A.; Duncan, G. C.

    1994-05-01

    We present results for 2-D, axisymmetric simulations of flows with Lorentz factors ~ 5 -- 10, typical of values inferred for superluminal BL Lacs and QSOs. The simulations were performed with a numerical hydrodynamic code that admits relativistic flow speed. We exploit the property that the relativistic Euler equations for mass, momentum and total energy densities in the laboratory frame have the same form as the nonrelativistic equations, to solve for laboratory frame variables using a conventional Godunov-type scheme with approximate Riemann solver: the HLLE method. The relativistic nature of the flow is incorporated by performing a Lorentz transformation at every step, at each cell center or cell boundary where pressure, sound speed or velocity are required. Determination of the velocity in this manner is a robust algebraic procedure within which we can ensure that vrelativistic flows exhibit a less pronounced pattern of incident and reflection shocks on axis. For flows which have propagated to a fixed number of jet radii, the Kelvin-Helmholtz instability at the contact surface is much less evident in the high Lorentz factor cases, supporting the contention that relativistic flows are less prone to such instability. We describe how the morphology of the cocoon and shocked ambient gas change with increasing Lorentz factor. This work was supported by NSF grant AST 9120224 and by the Ohio Supercomputer Center from a Cray Research Software Development Grant.

  10. Relativistic MHD simulations of extragalactic jets

    NASA Astrophysics Data System (ADS)

    Leismann, T.; Antón, L.; Aloy, M. A.; Müller, E.; Martí, J. M.; Miralles, J. A.; Ibáñez, J. M.

    2005-06-01

    We have performed a comprehensive parameter study of the morphology and dynamics of axisymmetric, magnetized, relativistic jets by means of numerical simulations. The simulations have been performed with an upgraded version of the GENESIS code which is based on a second-order accurate finite volume method involving an approximate Riemann solver suitable for relativistic ideal magnetohydrodynamic flows, and a method of lines. Starting from pure hydrodynamic models we consider the effect of a magnetic field of increasing strength (up to β ≡ |b|2/2p ≈ 3.3 times the equipartition value) and different topology (purely toroidal or poloidal). We computed several series of models investigating the dependence of the dynamics on the magnetic field in jets of different beam Lorentz factor and adiabatic index. We find that the inclusion of the magnetic field leads to diverse effects which contrary to Newtonian magnetohydrodynamics models do not always scale linearly with the (relative) strength of the magnetic field. The relativistic models show, however, some clear trends. Axisymmetric jets with toroidal magnetic fields produce a cavity which consists of two parts: an inner one surrounding the beam which is compressed by magnetic forces, and an adjacent outer part which is inflated due to the action of the magnetic field. The outer border of the outer part of the cavity is given by the bow-shock where its interaction with the external medium takes place. Toroidal magnetic fields well below equipartition (β = 0.05) combined with a value of the adiabatic index of 4/3 yield extremely smooth jet cavities and stable beams. Prominent nose cones form when jets are confined by toroidal fields and carry a high Poynting flux (σ≡ |b|2/ρ>0.01 and β≥ 1). In contrast, none of our models possessing a poloidal field develops such a nose cone. The size of the nose cone is correlated with the propagation speed of the Mach disc (the smaller the speed the larger is the size). If two

  11. Oscillator strengths of some Ba lines - A treatment including core-valence correlation and relativistic effects

    NASA Technical Reports Server (NTRS)

    Bauschlicher, C. W., Jr.; Jaffe, R. L.; Langhoff, S. R.; Partridge, H.; Mascarello, F. G.

    1985-01-01

    Theoretical calculations of selected excitation energies and oscillator strengths for Ba are presented that overcome the difficulties of previous theoretical treatments. A relativistic effective-core potential treatment is used to account for the relativistic core contraction, but the outermost ten electrons are treated explicitly. Core-valence correlation can be included in this procedure in a rigorous and systematic way through a configuration-interaction calculation. Insight is gained into the importance of relativistic effects by repeating many of the calculations using an all-electron nonrelativistic treatment employing an extended Slater basis set. It is found that the intensity of the intercombination line 3P1-1S0 is accurately determined by accounting for the deviation from LS coupling through spin-orbit mixing with the 1P1 state, and that deviations from the Lande interval rule provide an accurate measure of the degree of mixing.

  12. Calculation of the lowest electronic excitations of the alkaline earth metals using the relativistic polarization propagator

    NASA Astrophysics Data System (ADS)

    Brandt, Sven; Pernpointner, Markus

    2015-07-01

    In this work we use the recently implemented four-component polarization propagator for accurate single excitation calculations of alkaline earth metals and compare our results to experimental data. Various approximations to the Dirac-Coulomb Hamiltonian are additionally tested. In Ca spin-orbit coupling already leads to noticeable zero field splitting, which gradually increases for the heavier homologs finally invalidating the singlet and triplet state characterizations. For all systems we observe a very good agreement with experimental transition energies in the considered energy range. For Sr, Ba and Ra non-relativistic approaches already exhibit unacceptable deviations in the reproduction of transition energies and spectral structure. The obtained excited final states are analyzed in terms of atomic donor and acceptor orbital contributions. Our results stress the necessity to use relativistic implementations of the polarization propagator for an accurate description of both electron correlation and relativistic effects contributing to excitation spectra of heavy systems.

  13. Relativistic ionization fronts in gas jets

    NASA Astrophysics Data System (ADS)

    Lemos, Nuno; Dias, J. M.; Gallacher, J. G.; Issac, R. C.; Fonseca, R. A.; Lopes, N. C.; Silva, L. O.; Mendonça, J. T.; Jaroszynski, D. A.

    2006-10-01

    A high-power ultra-short laser pulse propagating through a gas jet, ionizes the gas by tunnelling ionization, creating a relativistic plasma-gas interface. The relativistic ionization front that is created can be used to frequency up-shift electromagnetic radiation either in co-propagation or in counter-propagation configurations. In the counter-propagation configuration, ionization fronts can act as relativistic mirrors for terahertz radiation, leading to relativistic double Doppler frequency up-shift to the visible range. In this work, we identified and explored, the parameters that optimize the key features of relativistic ionization fronts for terahertz radiation reflection. The relativistic ionization front generated by a high power laser (TOPS) propagating in a supersonic gas jet generated by a Laval nozzle has been fully characterized. We have also performed detailed two-dimensional relativistic particle-in-cell simulations with Osiris 2.0 to analyze the generation and propagation of the ionization fronts.

  14. Relativistic Celestial Mechanics of the Solar System

    NASA Astrophysics Data System (ADS)

    Kopeikin, Sergei; Efroimsky, Michael; Kaplan, George

    2011-09-01

    allows us to to discover and eliminate spurious coordinate effects that have no physical meaning. The basic mathematical technique used in our theoretical treatment is based on matching of asymptotic post-Newtonian expansions of the solutions of the gravity field equations. In Chapter 6, we discuss the principles of relativistic celestial mechanics of massive bodies and particles. We focus on derivation of the post-Newtonian equations of orbital and rotational motion of an extended body possessing multipolar moments. These moments couple with the tidal gravitational fields of other bodies, making the motion of the body under consideration very complicated. Simplification is possible if the body can be assumed spherically symmetric. We discuss the conditions under which this simplification can be afforded, and derive the equations of motion of spherically-symmetric bodies. These equations are solved in the case of the two-body problem, and we demonstrate the rich nature of the possible coordinate presentations of such a solution. The relativistic celestial mechanics of light particles (photons) propagating in a time-dependent gravitational field of an N-body system is addressed in Chapter 7. This is a primary subject of relativistic astrometry which became especially important for the analysis of space observations from the Hipparcos satellite in the early 1990s. New astrometric space missions, orders of magnitude more accurate than Hipparcos, for example, Gaia, SIM, JASMINE, and so on, will require even more complete developments. Additionally, relativistic effects play an important role in other areas of modern astronomy, such as, pulsar timing, very long baseline radio interferometry, cosmological gravitational lensing, and so on. High-precision measurements of gravitational light bending in the solar system are among the most crucial experimental tests of the general theory of relativity. Einstein predicted that the amount of light bending by the Sun is twice that

  15. Relativistic stars in bigravity theory

    NASA Astrophysics Data System (ADS)

    Aoki, Katsuki; Maeda, Kei-ichi; Tanabe, Makoto

    2016-03-01

    Assuming static and spherically symmetric spacetimes in the ghost-free bigravity theory, we find a relativistic star solution, which is very close to that in general relativity. The coupling constants are classified into two classes: Class [I] and Class [II]. Although the Vainshtein screening mechanism is found in the weak gravitational field for both classes, we find that there is no regular solution beyond the critical value of the compactness in Class [I]. This implies that the maximum mass of a neutron star in Class [I] becomes much smaller than that in general relativity (GR). On the other hand, for the solution in Class [II], the Vainshtein screening mechanism works well even in a relativistic star and the result in GR is recovered.

  16. Relativistic hydrodynamics on graphic cards

    NASA Astrophysics Data System (ADS)

    Gerhard, Jochen; Lindenstruth, Volker; Bleicher, Marcus

    2013-02-01

    We show how to accelerate relativistic hydrodynamics simulations using graphic cards (graphic processing units, GPUs). These improvements are of highest relevance e.g. to the field of high-energetic nucleus-nucleus collisions at RHIC and LHC where (ideal and dissipative) relativistic hydrodynamics is used to calculate the evolution of hot and dense QCD matter. The results reported here are based on the Sharp And Smooth Transport Algorithm (SHASTA), which is employed in many hydrodynamical models and hybrid simulation packages, e.g. the Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). We have redesigned the SHASTA using the OpenCL computing framework to work on accelerators like graphic processing units (GPUs) as well as on multi-core processors. With the redesign of the algorithm the hydrodynamic calculations have been accelerated by a factor 160 allowing for event-by-event calculations and better statistics in hybrid calculations.

  17. Magnetohydrodynamics of chiral relativistic fluids

    NASA Astrophysics Data System (ADS)

    Boyarsky, Alexey; Fröhlich, Jürg; Ruchayskiy, Oleg

    2015-08-01

    We study the dynamics of a plasma of charged relativistic fermions at very high temperature T ≫m , where m is the fermion mass, coupled to the electromagnetic field. In particular, we derive a magnetohydrodynamical description of the evolution of such a plasma. We show that, compared to conventional magnetohydronamics (MHD) for a plasma of nonrelativistic particles, the hydrodynamical description of the relativistic plasma involves new degrees of freedom described by a pseudoscalar field originating in a local asymmetry in the densities of left-handed and right-handed fermions. This field can be interpreted as an effective axion field. Taking into account the chiral anomaly we present dynamical equations for the evolution of this field, as well as of other fields appearing in the MHD description of the plasma. Due to its nonlinear coupling to helical magnetic fields, the axion field significantly affects the dynamics of a magnetized plasma and can give rise to a novel type of inverse cascade.

  18. Relativistic rocket: Dream and reality

    NASA Astrophysics Data System (ADS)

    Semyonov, Oleg G.

    2014-06-01

    The dream of interstellar flights persists since the first pioneers in astronautics and has never died. Many concepts of thruster capable to propel a rocket to the stars have been proposed and the most suitable among them are thought to be photon propulsion and propulsion by the products of proton-antiproton annihilation in magnetic nozzle. This article addresses both concepts allowing for cross-section of annihilation among other issues in order to show their vulnerability and to indicate the problems. The concept of relativistic matter propulsion is substantiated and discussed. The latter is argued to be the most straightforward way to build-up a relativistic rocket firstly because it is based on the existing technology of ion generators and accelerators and secondly because it can be stepped up in efflux power starting from interplanetary spacecrafts powered by nuclear reactors to interstellar starships powered by annihilation reactors. The problems imposed by thermodynamics and heat disposal are accentuated.

  19. Fully relativistic lattice Boltzmann algorithm

    SciTech Connect

    Romatschke, P.; Mendoza, M.; Succi, S.

    2011-09-15

    Starting from the Maxwell-Juettner equilibrium distribution, we develop a relativistic lattice Boltzmann (LB) algorithm capable of handling ultrarelativistic systems with flat, but expanding, spacetimes. The algorithm is validated through simulations of a quark-gluon plasma, yielding excellent agreement with hydrodynamic simulations. The present scheme opens the possibility of transferring the recognized computational advantages of lattice kinetic theory to the context of both weakly and ultrarelativistic systems.

  20. Dynamics of Relativistic Magnetized Explosions

    NASA Astrophysics Data System (ADS)

    Lyutikov, M.

    2001-11-01

    The dynamics of (i) relativistic blast waves propagating through magnetized medium, (ii) magnetic explosions (when most energy is released in a form of toroidal magnetic field) is considered taking into account possible inhomogeneities of density and external magnetic field and additional energy supply. Self-similar solutions for the internal structure in the bulk flow and in the strongly magnetized sheath near contact discontinuity are found.

  1. Double-sided Relativistic Magnetron

    NASA Astrophysics Data System (ADS)

    Agafonov, A. V.; Krastelev, E. G.

    1997-05-01

    A new scheme of a symmetricaly powered relativistic magnetron and several methods of localised electron flow forming in an interaction region are proposed to increase an efficiency of relativistic magnetrons. As will be shown, a very important reason is the effect of nonsymmetric feeding of power from one side of a magnetron, which is typical for experiments. One-sided powering leads to the axial drift of electrons, to the transformation of transverse velocities of electrons to longitudinal one and to the generation of a parasitic e-beam which does not take part in energy exchange between electrons and waves at all. A special driver was designed for double-sided powering of relativistic magnetrons. The proposed system is compact, rigid and capable of reliable operation at high repetition rates, which is advantageous for many applications. Several smooth-bore magnetrons were tested by means of computer simulations using PIC code KARAT. The results showed a dramatical difference between the dynamics of electron flow for one- and two-sided power feeding of a structure under test. Design of a driver and computer simulation results are presented.

  2. Relativistic opacities for astrophysical applications

    NASA Astrophysics Data System (ADS)

    Fontes, C. J.; Fryer, C. L.; Hungerford, A. L.; Hakel, P.; Colgan, J.; Kilcrease, D. P.; Sherrill, M. E.

    2015-09-01

    We report on the use of the Los Alamos suite of relativistic atomic physics codes to generate radiative opacities for the modeling of astrophysically relevant plasmas under local thermodynamic equilibrium (LTE) conditions. The atomic structure calculations are carried out in fine-structure detail, including full configuration interaction. Three example applications are considered: iron opacities at conditions relevant to the base of the solar convection zone, nickel opacities for the modeling of stellar envelopes, and samarium opacities for the modeling of light curves produced by neutron star mergers. In the first two examples, comparisons are made between opacities that are generated with the fully and semi-relativistic capabilities in the Los Alamos suite of codes. As expected for these highly charged, iron-peak ions, the two methods produce reasonably similar results, providing confidence that the numerical methods have been correctly implemented. However, discrepancies greater than 10% are observed for nickel and investigated in detail. In the final application, the relativistic capability is used in a preliminary investigation of the complicated absorption spectrum associated with cold lanthanide elements.

  3. Relativistic Tennis Using Flying Mirror

    SciTech Connect

    Pirozhkov, A. S.; Kando, M.; Ma, J.; Fukuda, Y.; Chen, L.-M.; Daito, I.; Ogura, K.; Homma, T.; Hayashi, Y.; Kotaki, H.; Sagisaka, A.; Mori, M.; Koga, J. K.; Kawachi, T.; Daido, H.; Kimura, T.; Kato, Y.; Tajima, T.; Esirkepov, T. Zh.; Bulanov, S. V.

    2008-06-24

    Upon reflection from a relativistic mirror, the electromagnetic pulse frequency is upshifted and the duration is shortened by the factor proportional to the relativistic gamma-factor squared due to the double Doppler effect. We present the results of the proof-of-principle experiment for frequency upshifting of the laser pulse reflected from the relativistic 'flying mirror', which is a wake wave near the breaking threshold created by a strong driver pulse propagating in underdense plasma. Experimentally, the wake wave is created by a 2 TW, 76 fs Ti:S laser pulse from the JLITE-X laser system in helium plasma with the electron density of {approx_equal}4-6x10{sup 19} cm{sup -3}. The reflected signal is observed with a grazing-incidence spectrograph in 24 shots. The wavelength of the reflected radiation ranges from 7 to 14 nm, the corresponding frequency upshifting factors are {approx}55-115, and the gamma-factors are y = 4-6. The reflected signal contains at least 3x10{sup 7} photons/sr. This effect can be used to generate coherent high-frequency ultrashort pulses that inherit temporal shape and polarization from the original (low-frequency) ones. Apart from this, the reflected radiation contains important information about the wake wave itself, e.g. location, size, phase velocity, etc.

  4. NNLOPS accurate associated HW production

    NASA Astrophysics Data System (ADS)

    Astill, William; Bizon, Wojciech; Re, Emanuele; Zanderighi, Giulia

    2016-06-01

    We present a next-to-next-to-leading order accurate description of associated HW production consistently matched to a parton shower. The method is based on reweighting events obtained with the HW plus one jet NLO accurate calculation implemented in POWHEG, extended with the MiNLO procedure, to reproduce NNLO accurate Born distributions. Since the Born kinematics is more complex than the cases treated before, we use a parametrization of the Collins-Soper angles to reduce the number of variables required for the reweighting. We present phenomenological results at 13 TeV, with cuts suggested by the Higgs Cross section Working Group.

  5. Relativistic extension of the complex scaled Green function method

    NASA Astrophysics Data System (ADS)

    Shi, Min; Guo, Jian-You; Liu, Quan; Niu, Zhong-Ming; Heng, Tai-Hua

    2015-11-01

    Resonances play a critical role in the formation of many physical phenomena. The complex scaled Green function method provides a powerful tool for the exploration of resonances. In the paper, we extend this method to the relativistic framework. With 120Sn as an example, we present the details of the scheme and seek resonant states in real nuclei. The results are compared, and are in satisfactory agreement with those from frequently used methods. In particular, the present method gathers the advantages of the complex scaling method and Green function method, and can be used to determine more accurately resonance parameters such as energy and lifetime of decay.

  6. A finite Zitterbewegung model for relativistic quantum mechanics

    SciTech Connect

    Noyes, H.P.

    1990-02-19

    Starting from steps of length h/mc and time intervals h/mc{sup 2}, which imply a quasi-local Zitterbewegung with velocity steps {plus minus}c, we employ discrimination between bit-strings of finite length to construct a necessary 3+1 dimensional event-space for relativistic quantum mechanics. By using the combinatorial hierarchy to label the strings, we provide a successful start on constructing the coupling constants and mass ratios implied by the scheme. Agreement with experiments is surprisingly accurate. 22 refs., 1 fig.

  7. Relativistic Effects Around Black Holes: Smearing Absorption Edges

    NASA Technical Reports Server (NTRS)

    Zhang, X. L.; Feng, Y. X.; Zhang, S. N.; Yao, Y.

    2002-01-01

    Broad iron absorption structures have been observed in the X-ray spectra of both AGNs and black hole X-ray binaries (BHXBs). A correctly modeled absorption structure can reveal the physical condition of the source, help to determine the continuum spectra and thus help to estimate other spectral lifes more accurately. The absorption structures are usually thought to be caused by the reflection of X-rays by the accretion disks around the central black holes, and the broadening can be a ttributed to the ionization states of the disk and relativistic effects.

  8. Cosmos++: Relativistic Magnetohydrodynamics on Unstructured Grids with Local Adaptive Refinement

    SciTech Connect

    Anninos, P; Fragile, P C; Salmonson, J D

    2005-05-06

    A new code and methodology are introduced for solving the fully general relativistic magnetohydrodynamic (GRMHD) equations using time-explicit, finite-volume discretization. The code has options for solving the GRMHD equations using traditional artificial-viscosity (AV) or non-oscillatory central difference (NOCD) methods, or a new extended AV (eAV) scheme using artificial-viscosity together with a dual energy-flux-conserving formulation. The dual energy approach allows for accurate modeling of highly relativistic flows at boost factors well beyond what has been achieved to date by standard artificial viscosity methods. it provides the benefit of Godunov methods in capturing high Lorentz boosted flows but without complicated Riemann solvers, and the advantages of traditional artificial viscosity methods in their speed and flexibility. Additionally, the GRMHD equations are solved on an unstructured grid that supports local adaptive mesh refinement using a fully threated oct-tree (in three dimensions) network to traverse the grid hierarchy across levels and immediate neighbors. A number of tests are presented to demonstrate robustness of the numerical algorithms and adaptive mesh framework over a wide spectrum of problems, boosts, and astrophysical applications, including relativistic shock tubes, shock collisions, magnetosonic shocks, Alfven wave propagation, blast waves, magnetized Bondi flow, and the magneto-rotational instability in Kerr black hole spacetimes.

  9. Finite Element Method for Capturing Ultra-relativistic Shocks

    NASA Technical Reports Server (NTRS)

    Richardson, G. A.; Chung, T. J.

    2003-01-01

    While finite element methods are used extensively by researchers solving computational fluid dynamics in fields other than astrophysics, their use in astrophysical fluid simulations has been predominantly overlooked. Current simulations using other methods such as finite difference and finite volume (based on finite difference) have shown remarkable results, but these methods are limited by their fundamental properties in aspects that are important for simulations with complex geometries and widely varying spatial and temporal scale differences. We have explored the use of finite element methods for astrophysical fluids in order to establish the validity of using such methods in astrophysical environments. We present our numerical technique applied to solving ultra-relativistic (Lorentz Factor Gamma >> 1) shocks which are prevalent in astrophysical studies including relativistic jets and gamma-ray burst studies. We show our finite element formulation applied to simulations where the Lorentz factor ranges up to 2236 and demonstrate its stability in solving ultra-relativistic flows. Our numerical method is based on the Flowfield Dependent Variation (FDV) Method, unique in that numerical diffusion is derived from physical parameters rather than traditional artificial viscosity methods. Numerical instabilities account for most of the difficulties when capturing shocks in this regime. Our method results in stable solutions and accurate results as compared with other methods.

  10. Relativistic atomic data for Cu-like tungsten

    NASA Astrophysics Data System (ADS)

    Safronova, U. I.; Safronova, A. S.; Beiersdorfer, P.

    2013-05-01

    Energy levels, radiative transition probabilities, and autoionization rates for [Ne] 3s2 3p6 3d9 4l' nl , [Ne] 3s2 3p5 3d10 4l' nl (n=4-6), and [Ne] 3s2 3p6 3d9 5l' nl ,(n=5-7) states in Cu-like tungsten (W45+) are calculated using the relativistic many-body perturbation theory method (RMBPT code), the multiconfiguration relativistic Hebrew University Lawrence Livermore Atomic Code (HULLAC code), and the Hartree-Fock-relativistic method (COWAN code). Branching ratios relative to the first threshold and intensity factors are calculated for satellite lines, and dielectronic recombination (DR) rate coefficients are determined for the singly excited, as well as doubly excited non-autoionizing states in Cu-like W45+ ion. Contributions from the autoionizing doubly excited states (with n up to 500), which are particulary important for calculating total DR rates, are estimated. Synthetic dielectronic satellite spectra from Cu-like W are simulated in a broad spectral range from 3 to 70 Å. These calculations provide highly accurate values for a number of W45+ properties useful for a variety of applications including for fusion applications. This research was sponsored by the grant DE-FG02-08ER54951.

  11. How to accurately bypass damage

    PubMed Central

    Broyde, Suse; Patel, Dinshaw J.

    2016-01-01

    Ultraviolet radiation can cause cancer through DNA damage — specifically, by linking adjacent thymine bases. Crystal structures show how the enzyme DNA polymerase η accurately bypasses such lesions, offering protection. PMID:20577203

  12. Accurate Evaluation of Quantum Integrals

    NASA Technical Reports Server (NTRS)

    Galant, David C.; Goorvitch, D.

    1994-01-01

    Combining an appropriate finite difference method with Richardson's extrapolation results in a simple, highly accurate numerical method for solving a Schr\\"{o}dinger's equation. Important results are that error estimates are provided, and that one can extrapolate expectation values rather than the wavefunctions to obtain highly accurate expectation values. We discuss the eigenvalues, the error growth in repeated Richardson's extrapolation, and show that the expectation values calculated on a crude mesh can be extrapolated to obtain expectation values of high accuracy.

  13. Relativistic Navigation: A Theoretical Foundation

    NASA Technical Reports Server (NTRS)

    Turyshev, Slava G.

    1996-01-01

    We present a theoretical foundation for relativistic astronomical measurements in curved space-time. In particular, we discuss a new iterative approach for describing the dynamics of an isolated astronomical N-body system in metric theories of gravity. To do this, we generalize the Fock-Chandrasekhar method of the weak-field and slow-motion approximation (WFSMA) and develop a theory of relativistic reference frames (RF's) for a gravitationally bounded many-extended-body problem. In any proper RF constructed in the immediate vicinity of an arbitrary body, the N-body solutions of the gravitational field equations are formally presented as a sum of the Riemann-flat inertial space-time, the gravitational field generated by the body itself, the unperturbed solutions for each body in the system transformed to the coordinates of this proper RF, and the gravitational interaction term. We develop the basic concept of a general WFSMA theory of the celestial RF's applicable to a wide class of metric theories of gravity and an arbitrary model of matter distribution. We apply the proposed method to general relativity. Celestial bodies are described using a perfect fluid model; as such, they possess any number of internal mass and current multipole moments that explicitly characterize their internal structures. The obtained relativistic corrections to the geodetic equations of motion arise because of a coupling of the bodies' multiple moments to the surrounding gravitational field. The resulting relativistic transformations between the different RF's extend the Poincare group to the motion of deformable self-gravitating bodies. Within the present accuracy of astronomical measurements we discuss the properties of the Fermi-normal-like proper RF that is defined in the immediate vicinity of the extended compact bodies. We further generalize the proposed approximation method and include two Eddington parameters (gamma, Beta). This generalized approach was used to derive the

  14. Relativistic radiation transport in dispersive media

    SciTech Connect

    Kichenassamy, S.; Krikorian, R.A.

    1985-10-15

    A general-relativistic radiative transfer equation in an isotropic, weakly absorbing, nonmagnetized dispersive medium is derived using the kinetic-theoretical approach and the relativistic Hamiltonian theory of geometrical optics in those media. It yields the generally accepted classical equation in the special-relativistic approximation and in stationary conditions. The influence of the gravitational field and of space-time variations of the refractive index n on the radiation distribution is made explicit in the case of spherical symmetry.

  15. Mesoscopic Superposition States in Relativistic Landau Levels

    SciTech Connect

    Bermudez, A.; Martin-Delgado, M. A.; Solano, E.

    2007-09-21

    We show that a linear superposition of mesoscopic states in relativistic Landau levels can be built when an external magnetic field couples to a relativistic spin 1/2 charged particle. Under suitable initial conditions, the associated Dirac equation produces unitarily superpositions of coherent states involving the particle orbital quanta in a well-defined mesoscopic regime. We demonstrate that these mesoscopic superpositions have a purely relativistic origin and disappear in the nonrelativistic limit.

  16. Loading relativistic Maxwell distributions in particle simulations

    SciTech Connect

    Zenitani, Seiji

    2015-04-15

    Numerical algorithms to load relativistic Maxwell distributions in particle-in-cell (PIC) and Monte-Carlo simulations are presented. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are proposed in a physically transparent manner. Their acceptance efficiencies are ≈50% for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms.

  17. Loading relativistic Maxwell distributions in particle simulations

    NASA Astrophysics Data System (ADS)

    Zenitani, Seiji

    2015-04-01

    Numerical algorithms to load relativistic Maxwell distributions in particle-in-cell (PIC) and Monte-Carlo simulations are presented. For stationary relativistic Maxwellian, the inverse transform method and the Sobol algorithm are reviewed. To boost particles to obtain relativistic shifted-Maxwellian, two rejection methods are proposed in a physically transparent manner. Their acceptance efficiencies are ≈50 % for generic cases and 100% for symmetric distributions. They can be combined with arbitrary base algorithms.

  18. Relativistic and non-relativistic magnetohydrodynamic flows around compact stars

    NASA Astrophysics Data System (ADS)

    Mobarry, Clark Matthew

    A set of theoretical tools are developed for studying the magnetized accretion disks and astrophysical jets in active galaxies. A general theory is developed for the steady axisymmetric flow of an ideal general-relativistic fluid around a Schwarzschild black hole. The theory leads to a second-order partial differential equation, a Grad-Shafranov equation, for the magnetic flux function psi(R, theta). The magnetic surface functions of the Grad-Shafranov method are shown to be the Lagrange multipliers of an energy principle. Thus, the magnetic surface functions are not arbitrary functions, but must be chosen consistent with physically stable equilibria. From the energy principle, a numerical artificial friction method is developed to solve the general relativistic Grad-Shafranov equation with fluid flow. This method is suited for the internal boundaries between elliptic and hyperbolic behavior present in magnetospheres with fluid flow. The friction method is shown to be compatible with a theory for the slow dissipative evolution of a nearly ideal MagnetoHydroDynamic (MHD) fluid. A virial theorem is derived from the basic equations of general relativistic MHD. It is used to obtain an upper bound on the total energy in the electromagnetic field in terms of the total gravitational binding energy between the black hole and the matter (and energy) outside it. An analysis is made of the motion of a charged test particle in the electromagnetic field of a magnetized accretion disk surrounding a black hole. The results are consistent with stable orbits close to the event horizon. A semi-analytical model is developed for the evolution and dissipation of narrow magnetized jets from an active galaxy. This model exhibits the acceleration and expansion of the jets with increasing axial distance from the central object.

  19. Laser hosing in relativistically hot plasmas.

    PubMed

    Li, G; Mori, W B; Ren, C

    2013-04-12

    Electron response in an intense laser is studied in the regime where the electron temperature is relativistic. Equations for laser envelope and plasma density evolution, both in the electron plasma wave and ion acoustic wave regimes, are rederived from the relativistic fluid equations to include relativistic plasma temperature effect. These equations are used to study short-pulse and long-pulse laser hosing instabilities using a variational method approach. The analysis shows that relativistic electron temperatures reduce the hosing growth rates and shift the fastest-growing modes to longer wavelengths. These results resolve a long-standing discrepancy between previous nonrelativistic theory and simulations or experiments on hosing. PMID:25167277

  20. What is the relativistic spin operator?

    NASA Astrophysics Data System (ADS)

    Bauke, Heiko; Ahrens, Sven; Keitel, Christoph H.; Grobe, Rainer

    2014-04-01

    Although the spin is regarded as a fundamental property of the electron, there is no universally accepted spin operator within the framework of relativistic quantum mechanics. We investigate the properties of different proposals for a relativistic spin operator. It is shown that most candidates are lacking essential features of proper angular momentum operators, leading to spurious zitterbewegung (quivering motion) or violation of the angular momentum algebra. Only the Foldy-Wouthuysen operator and the Pryce operator qualify as proper relativistic spin operators. We demonstrate that ground states of highly charged hydrogen-like ions can be utilized to identify a legitimate relativistic spin operator experimentally.

  1. Dissipation in Relativistic Pair-Plasma Reconnection

    NASA Technical Reports Server (NTRS)

    Hesse, Michael; Zenitani, Seiji

    2007-01-01

    We present an investigation of the relativistic dissipation in magnetic reconnection. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm's law is derived. We analyze a set of numerical simulations, composed of runs with and without guide magnetic field, and of runs with different species temperatures. The calculations indicate that the thermal inertia-based dissipation process survives in relativistic plasmas. For anti-parallel reconnection, it is found that the pressure tensor divergence remains the sole contributor to the reconnection electric field, whereas relativistic guide field reconnection exhibits a similarly important role of the bulk inertia terms.

  2. Dissipation in relativistic pair-plasma reconnection

    SciTech Connect

    Hesse, Michael; Zenitani, Seiji

    2007-11-15

    An investigation into the relativistic dissipation in magnetic reconnection is presented. The investigated system consists of an electron-positron plasma. A relativistic generalization of Ohm's law is derived. A set of numerical simulations is analyzed, composed of runs with and without guide magnetic field, and of runs with different species temperatures. The calculations indicate that the thermal inertia-based dissipation process survives in relativistic plasmas. For antiparallel reconnection, it is found that the pressure tensor divergence remains the sole contributor to the reconnection electric field, whereas relativistic guide field reconnection exhibits a similarly important role of the bulk inertia terms.

  3. Relativistic Bernstein waves in a degenerate plasma

    SciTech Connect

    Ali, Muddasir; Hussain, Azhar; Murtaza, G.

    2011-09-15

    Bernstein mode for a relativistic degenerate electron plasma is investigated. Using relativistic Vlasov-Maxwell equations, a general expression for the conductivity tensor is derived and then employing Fermi-Dirac distribution function a generalized dispersion relation for the Bernstein mode is obtained. Two limiting cases, i.e., non-relativistic and ultra-relativistic are discussed. The dispersion relations obtained are also graphically presented for some specific values of the parameters depicting how the propagation characteristics of Bernstein waves as well as the Upper Hybrid oscillations are modified with the increase in plasma number density.

  4. Relativistic Plasma Polarizer: Impact of Temperature Anisotropy on Relativistic Transparency.

    PubMed

    Stark, David J; Bhattacharjee, Chinmoy; Arefiev, Alexey V; Toncian, Toma; Hazeltine, R D; Mahajan, S M

    2015-07-10

    3D particle-in-cell simulations demonstrate that the enhanced transparency of a relativistically hot plasma is sensitive to how the energy is partitioned between different degrees of freedom. For an anisotropic electron distribution, propagation characteristics, like the critical density, will depend on the polarization of the electromagnetic wave. Despite the onset of the Weibel instability in such plasmas, the anisotropy can persist long enough to affect laser propagation. This plasma can then function as a polarizer or a wave plate to dramatically alter the pulse polarization. PMID:26207473

  5. Relativistic and non-relativistic solitons in plasmas

    NASA Astrophysics Data System (ADS)

    Barman, Satyendra Nath

    This thesis entitled as "Relativistic and Non-relativistic Solitons in Plasmas" is the embodiment of a number of investigations related to the formation of ion-acoustic solitary waves in plasmas under various physical situations. The whole work of the thesis is devoted to the studies of solitary waves in cold and warm collisionless magnetized or unmagnetized plasmas with or without relativistic effect. To analyze the formation of solitary waves in all our models of plasmas, we have employed two established methods namely - reductive perturbation method to deduce the Korteweg-de Vries (KdV) equation, the solutions of which represent the important but near exact characteristic concepts of soliton-physics. Next, the pseudopotential method to deduce the energy integral with total nonlinearity in the coupling process for exact characteristic results of solitons has been incorporated. In Chapter 1, a brief description of plasma in nature and laboratory and its generation are outlined elegantly. The nonlinear differential equations to characterize solitary waves and the relevant but important methods of solutions have been mentioned in this chapter. The formation of solitary waves in unmagnetized and magnetized plasmas, and in relativistic plasmas has been described through mathematical entity. Applications of plasmas in different fields are also put forwarded briefly showing its importance. The study of plasmas as they naturally occur in the universe encompasses number of topics including sun's corona, solar wind, planetary magnetospheres, ionospheres, auroras, cosmic rays and radiation. The study of space weather to understand the universe, communications and the activities of weather satellites are some useful areas of space plasma physics. The surface cleaning, sterilization of food and medical appliances, killing of bacteria on various surfaces, destroying of viruses, fungi, spores and plasma coating in industrial instruments ( like computers) are some of the fields

  6. Accurate orbit propagation with planetary close encounters

    NASA Astrophysics Data System (ADS)

    Baù, Giulio; Milani Comparetti, Andrea; Guerra, Francesca

    2015-08-01

    We tackle the problem of accurately propagating the motion of those small bodies that undergo close approaches with a planet. The literature is lacking on this topic and the reliability of the numerical results is not sufficiently discussed. The high-frequency components of the perturbation generated by a close encounter makes the propagation particularly challenging both from the point of view of the dynamical stability of the formulation and the numerical stability of the integrator. In our approach a fixed step-size and order multistep integrator is combined with a regularized formulation of the perturbed two-body problem. When the propagated object enters the region of influence of a celestial body, the latter becomes the new primary body of attraction. Moreover, the formulation and the step-size will also be changed if necessary. We present: 1) the restarter procedure applied to the multistep integrator whenever the primary body is changed; 2) new analytical formulae for setting the step-size (given the order of the multistep, formulation and initial osculating orbit) in order to control the accumulation of the local truncation error and guarantee the numerical stability during the propagation; 3) a new definition of the region of influence in the phase space. We test the propagator with some real asteroids subject to the gravitational attraction of the planets, the Yarkovsky and relativistic perturbations. Our goal is to show that the proposed approach improves the performance of both the propagator implemented in the OrbFit software package (which is currently used by the NEODyS service) and of the propagator represented by a variable step-size and order multistep method combined with Cowell's formulation (i.e. direct integration of position and velocity in either the physical or a fictitious time).

  7. Benchmark calculations on the nuclear quadrupole-coupling parameters for open-shell molecules using non-relativistic and scalar-relativistic coupled-cluster methods

    SciTech Connect

    Cheng, Lan

    2015-08-14

    Quantum-chemical computations of nuclear quadrupole-coupling parameters for 24 open-shell states of small molecules based on non-relativistic and spin-free exact two-component (SFX2C) relativistic equation-of-motion coupled-cluster (EOM-CC) as well as spin-orbital-based restricted open-shell Hartree-Fock coupled-cluster (ROHF-CC) methods are reported. Relativistic effects, the performance of the EOM-CC and ROHF-CC methods for treating electron correlation, as well as basis-set convergence have been carefully analyzed. Consideration of relativistic effects is necessary for accurate calculations on systems containing third-row (K-Kr) and heavier elements, as expected, and the SFX2C approach is shown to be a useful cost-effective option here. Further, it is demonstrated that the EOM-CC methods constitute flexible and accurate alternatives to the ROHF-CC methods in the calculations of nuclear quadrupole-coupling parameters for open-shell states.

  8. Response to Geometric Distortions from Atom-Based Relativistic Projection on Electronic States

    SciTech Connect

    Matveev, Alexei V.; Roesch, Notker

    2007-12-26

    We suggest a quasi-relativistic model for molecular electronic structure calculations obtained by an atomic ansatz for the relativistic projection transformation. With such a choice, the projection transformation becomes both transferable and independent of the geometry. The formulation is flexible with regard to the choice of the projection transformation. We employ the free-particle Foldy-Wouthuysen and the Douglas-Kroll second-order variants for the projection coefficients. First results for the diatomic molecules AuH, AuCl, and Au{sub 2} and two structural isomers of Ir{sub 4} suggest the new approximate method as an efficient and accurate replacement for the conventional transformation.

  9. Relativistic Plasma Polarizer: Impact of Temperature Anisotropy on Relativistic Transparency

    NASA Astrophysics Data System (ADS)

    Hazeltine, R. D.; Stark, David J.; Bhattacharjee, Chinmoy; Arefiev, Alexey V.; Toncian, Toma; Mahajan, S. M.

    2015-11-01

    3D particle-in-cell simulations demonstrate that the enhanced transparency of a relativistically hot plasma is sensitive to how the energy is partitioned between different degrees of freedom. We consider here the simplest problem: the propagation of a low amplitude pulse through a preformed relativistically hot anisotropic electron plasma to explore its intrinsic dielectric properties. We find that: 1) the critical density for propagation depends strongly on the pulse polarization, 2) two plasmas with the same density and average energy per electron can exhibit profoundly different responses to electromagnetic pulses, 3) the anisotropy-driven Weibel instability develops as expected; the timescales of the growth and back reaction (on anisotropy), however, are long enough that sufficient anisotropy persists for the entire duration of the simulation. This plasma can then function as a polarizer or a wave plate to dramatically alter the pulse polarization. This work was supported by the U.S. DOE Contract Nos. DE-FG02-04ER54742 and DE-AC05-06OR23100 (D. J. S.) and NNSA Contract No. DE-FC52-08NA28512.

  10. Relativistic radiative transfer and relativistic spherical shell flows

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2016-06-01

    We examine a radiatively driven spherical flow from a central object, whose thickness is smaller than the radius of the central object, and a plane-parallel approximation can be used-a spherical shell flow. We first solve the relativistic radiative transfer equation iteratively, using a given velocity field, and obtain specific intensities as well as moment quantities. Using the obtained comoving flux, we then solve the relativistic hydrodynamical equation, and obtain a new velocity field. We repeat these double iteration processes until both the intensity and velocity profiles converge. We found that the flow speed v(τ) is roughly approximated as β ≡ v/c = βs(1 - τ/τb), where τ is the optical depth, τb the flow total optical depth, and c the speed of light. We further found that the flow terminal speed vs is roughly expressed as β _s ≡ v_s/c = (Γ hat{F}_0-1)τ_b/dot{m} , where Γ is the central luminosity normalized by the Eddington luminosity, hat{F}_0 the comoving flux normalized by the incident flux, and of the order of unity, and dot{m} the mass-loss rate normalized by the critical mass loss.

  11. Relativistic radiative transfer and relativistic spherical shell flows

    NASA Astrophysics Data System (ADS)

    Fukue, Jun

    2016-04-01

    We examine a radiatively driven spherical flow from a central object, whose thickness is smaller than the radius of the central object, and a plane-parallel approximation can be used-a spherical shell flow. We first solve the relativistic radiative transfer equation iteratively, using a given velocity field, and obtain specific intensities as well as moment quantities. Using the obtained comoving flux, we then solve the relativistic hydrodynamical equation, and obtain a new velocity field. We repeat these double iteration processes until both the intensity and velocity profiles converge. We found that the flow speed v(τ) is roughly approximated as β ≡ v/c = βs(1 - τ/τb), where τ is the optical depth, τb the flow total optical depth, and c the speed of light. We further found that the flow terminal speed vs is roughly expressed as β _s ≡ v_s/c = (Γ hat{F}_0-1)τ_b/dot{m} , where Γ is the central luminosity normalized by the Eddington luminosity, hat{F}_0 the comoving flux normalized by the incident flux, and of the order of unity, and dot{m} the mass-loss rate normalized by the critical mass loss.

  12. Relativistic mean-field theory

    NASA Astrophysics Data System (ADS)

    Meng, Jie; Ring, Peter; Zhao, Pengwei

    In this chapter, the covariant energy density functional is constructed with both the meson-exchange and the point-coupling pictures. Several widely used functionals with either nonlinear or density-dependent effective interactions are introduced. The applications of covariant density functional theory are demonstrated for infinite nuclear matter and finite nuclei with spherical symmetry, axially symmetric quadrupole deformation, and triaxial quadrupole shapes. Finally, a relativistic description of the nuclear landscape has been discussed, which is not only important for nuclear structure, but also important for nuclear astrophysics, where we are facing the problem of a reliable extrapolation to the very neutron-rich nuclei.

  13. Thermodynamics of polarized relativistic matter

    NASA Astrophysics Data System (ADS)

    Kovtun, Pavel

    2016-07-01

    We give the free energy of equilibrium relativistic matter subject to external gravitational and electromagnetic fields, to one-derivative order in the gradients of the external fields. The free energy allows for a straightforward derivation of bound currents and bound momenta in equilibrium. At leading order, the energy-momentum tensor admits a simple expression in terms of the polarization tensor. Beyond the leading order, electric and magnetic polarization vectors are intrinsically ambiguous. The physical effects of polarization, such as the correlation between the magneto-vortically induced surface charge and the electro-vortically induced surface current, are not ambiguous.

  14. Einstein Toolkit for Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Collaborative Effort

    2011-02-01

    The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.

  15. Vortices in relativistic electron beams

    PubMed

    Jovanovic; Fedele; Shukla

    2000-08-01

    We demonstrate that a relativistic electron beam is properly described in the moving frame by the electron-magnetohydrodynamic equations of plasma physics. For large beam currents, the accelerator magnetic field is expected to be unstable to the fast magnetic reconnection. We present a plausible saturated state of the fast reconnection, in the form of a complex vortex pattern. The nonlinear dispersion equations of the vortex are derived and the relationship between the vortex structure and the background magnetic field is discussed. PMID:11088759

  16. Relativistic heavy ion facilities: worldwide

    SciTech Connect

    Schroeder, L.S.

    1986-05-01

    A review of relativistic heavy ion facilities which exist, are in a construction phase, or are on the drawing boards as proposals is presented. These facilities span the energy range from fixed target machines in the 1 to 2 GeV/nucleon regime, up to heavy ion colliders of 100 GeV/nucleon on 100 GeV/nucleon. In addition to specifying the general features of such machines, an outline of the central physics themes to be carried out at these facilities is given, along with a sampling of the detectors which will be used to extract the physics. 22 refs., 17 figs., 3 tabs.

  17. Relativistic atomic beam spectroscopy II

    SciTech Connect

    1989-12-31

    The negative ion of H is one of the simplest 3-body atomic systems. The techniques we have developed for experimental study of atoms moving near speed of light have been productive. This proposal request continuing support for experimental studies of the H{sup -} system, principally at the 800 MeV linear accelerator (LAMPF) at Los Alamos. Four experiments are currently planned: photodetachment of H{sup -} near threshold in electric field, interaction of relativistic H{sup -} ions with matter, high excitations and double charge escape in H{sup -}, and multiphoton detachment of electrons from H{sup -}.

  18. Relativistic jets and star formation

    NASA Astrophysics Data System (ADS)

    Bicknell, Geoffrey Vincent; Mukherjee, Dipanjan; Wagner, Alex; Slatyer Sutherland, Ralph

    2015-08-01

    We are conducting simulations of jets interacting with molecular and atomic gas on scales of a few kpc in forming galaxies. Competing processes, such as the dispersion of gas in the galaxy and star formation in the high-pressure environment determine whether positive or negative feedback predominates. We shall present our new simulations including an assessment of these different effects. Our simulations also predict the velocity and velocity dispersion of atomic and molecular gas in galaxies, which are undergoing interaction with relativistic jets. These results are of interest to radio and optical spectral imaging observations of galaxies undergoing feedback.

  19. Relativistic quantum private database queries

    NASA Astrophysics Data System (ADS)

    Sun, Si-Jia; Yang, Yu-Guang; Zhang, Ming-Ou

    2015-04-01

    Recently, Jakobi et al. (Phys Rev A 83, 022301, 2011) suggested the first practical private database query protocol (J-protocol) based on the Scarani et al. (Phys Rev Lett 92, 057901, 2004) quantum key distribution protocol. Unfortunately, the J-protocol is just a cheat-sensitive private database query protocol. In this paper, we present an idealized relativistic quantum private database query protocol based on Minkowski causality and the properties of quantum information. Also, we prove that the protocol is secure in terms of the user security and the database security.

  20. Adaptive wavelets and relativistic magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Hirschmann, Eric; Neilsen, David; Anderson, Matthe; Debuhr, Jackson; Zhang, Bo

    2016-03-01

    We present a method for integrating the relativistic magnetohydrodynamics equations using iterated interpolating wavelets. Such provide an adaptive implementation for simulations in multidimensions. A measure of the local approximation error for the solution is provided by the wavelet coefficients. They place collocation points in locations naturally adapted to the flow while providing expected conservation. We present demanding 1D and 2D tests includingthe Kelvin-Helmholtz instability and the Rayleigh-Taylor instability. Finally, we consider an outgoing blast wave that models a GRB outflow.

  1. Arbitrarily Long Relativistic Bit Commitment

    NASA Astrophysics Data System (ADS)

    Chakraborty, Kaushik; Chailloux, André; Leverrier, Anthony

    2015-12-01

    We consider the recent relativistic bit commitment protocol introduced by Lunghi et al. [Phys. Rev. Lett. 115, 030502 (2015)] and present a new security analysis against classical attacks. In particular, while the initial complexity of the protocol scales double exponentially with the commitment time, our analysis shows that the correct dependence is only linear. This has dramatic implications in terms of implementation: in particular, the commitment time can easily be made arbitrarily long, by only requiring both parties to communicate classically and perform efficient classical computation.

  2. Relativistic electrons associated with solar flares.

    NASA Technical Reports Server (NTRS)

    Sakurai, K.

    1972-01-01

    Solar flares which produce relativistic electrons generally occur within sunspot groups which are active in the emission of meter type I noise storms. It is suggested that relativistic electrons in solar flares are accelerated from the keV-energy electrons responsible for the type I noise storms. The relationship between flare developments and the ejection of keV-electrons is briefly considered.

  3. Comparative SEU sensitivities to relativistic heavy ions

    SciTech Connect

    Koga, R.; Crain, S.H.; Crain, W.R.; Crawford, K.B.; Hansel, S.J.

    1998-12-01

    SEU sensitivity of microcircuits to relativistic heavy ions is compared to that measured with low-energy ions of comparable LET values. Multiple junction charge collection in a complex circuit seems to mask the effect of varying charge generations due to different iron track structures. Heavy ions at sub-relativistic speeds may generate nuclear fragments, sometimes resulting in SEUs.

  4. Einstein Never Approved of Relativistic Mass

    ERIC Educational Resources Information Center

    Hecht, Eugene

    2009-01-01

    During much of the 20th century it was widely believed that one of the significant insights of special relativity was "relativistic mass." Today there are two schools on that issue: the traditional view that embraces speed-dependent "relativistic mass," and the more modern position that rejects it, maintaining that there is only one mass and it's…

  5. Representation of relativistic quantities by trigonometric functions

    NASA Astrophysics Data System (ADS)

    Majerník, V.

    1986-06-01

    A ``space-time angle'' φ is defined by setting v=c(sin φ). This leads to a form of Lorentz transformations which uses simple real trigonometric functions and yields a graphic correlation of important relativistic quantities for particles and for corresponding de Broglie waves. A number of relativistic relationships is obtained by the use of common trigonometric identities and formulas.

  6. Compton Effect with Non-Relativistic Kinematics

    ERIC Educational Resources Information Center

    Shivalingaswamy, T.; Kagali, B. A.

    2011-01-01

    In deducing the change of wavelength of x-rays scattered by atomic electrons, one normally makes use of relativistic kinematics for electrons. However, recoiling energies of the electrons are of the order of a few keV which is less than 0.2% of their rest energies. Hence the authors may ask whether relativistic formulae are really necessary. In…

  7. Nonlinear, relativistic Langmuir waves in astrophysical magnetospheres

    NASA Technical Reports Server (NTRS)

    Chian, Abraham C.-L.

    1987-01-01

    Large amplitude, electrostatic plasma waves are relevant to physical processes occurring in the astrophysical magnetospheres wherein charged particles are accelerated to relativistic energies by strong waves emitted by pulsars, quasars, or radio galaxies. The nonlinear, relativistic theory of traveling Langmuir waves in a cold plasma is reviewed. The cases of streaming electron plasma, electronic plasma, and two-streams are discussed.

  8. Lattice Boltzmann equation for relativistic quantum mechanics.

    PubMed

    Succi, Sauro

    2002-03-15

    Relativistic versions of the quantum lattice Boltzmann equation are discussed. It is shown that the inclusion of nonlinear interactions requires the standard collision operator to be replaced by a pair of dynamic fields coupling to the relativistic wave function in a way which can be described by a multicomponent complex lattice Boltzmann equation. PMID:16210189

  9. Non-relativistic scale anomalies

    NASA Astrophysics Data System (ADS)

    Arav, Igal; Chapman, Shira; Oz, Yaron

    2016-06-01

    We extend the cohomological analysis in arXiv:1410.5831 of anisotropic Lifshitz scale anomalies. We consider non-relativistic theories with a dynamical critical exponent z = 2 with or without non-relativistic boosts and a particle number symmetry. We distinguish between cases depending on whether the time direction does or does not induce a foliation structure. We analyse both 1 + 1 and 2 + 1 spacetime dimensions. In 1 + 1 dimensions we find no scale anomalies with Galilean boost symmetries. The anomalies in 2 + 1 dimensions with Galilean boosts and a foliation structure are all B-type and are identical to the Lifshitz case in the purely spatial sector. With Galilean boosts and without a foliation structure we find also an A-type scale anomaly. There is an infinite ladder of B-type anomalies in the absence of a foliation structure with or without Galilean boosts. We discuss the relation between the existence of a foliation structure and the causality of the field theory.

  10. 3-D Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Nishikaw, K.-I.; Frank, J.; Christodoulou, D. M.; Koide, S.; Sakai, J.-I.; Sol, H.; Mutel, R. L.

    1998-12-01

    We present 3-D numerical simulations of moderately hot, supersonic jets propagating initially along or obliquely to the field lines of a denser magnetized background medium with Lorentz factors of W=4.56 and evolving in a four-dimensional spacetime. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently in the simulations. This effect is analogous to pushing Japanese ``noren'' or vertical Venetian blinds out of the way while the slats are allowed to bend in 3-D space rather than as a 2-D slab structure. We also simulate jets with the more realistic initial conditions for injecting jets for helical mangetic field, perturbed density, velocity, and internal energy, which are supposed to be caused in the process of jet generation. Three possible explanations for the observed variability are (i) tidal disruption of a star falling into the black hole, (ii) instabilities in the relativistic accretion disk, and (iii) jet-related PRocesses. New results will be reported at the meeting.

  11. Relativistic Laser-Plasma Interactions

    SciTech Connect

    Skoric, Milos M.

    2009-11-10

    Ever since the much acclaimed paper of Akhiezer and Polovin plasma theorists have been attempting to comprehend complex dynamics related to the propagation of high and ultra-high intensity electromagnetic (EM) radiation through a plasma. This topic was successfully revisited a number of years later by Kaw and Dawson whose analysis threw more light on the propagation of coupled longitudinal-transverse waves of arbitrary intensity. The high phase velocity case was soon solved exactly by Max and Perkins, (early review). The problem of relativistic laser-plasma interactions is of particular interest concerning the fast ignition concept, relevant to contemporary laser inertial confinement fusion research. Moreover, the understanding of relativistic laser pulse evolution in a plasma is basic to many new applications, including optical-field-ionized x-ray lasers, plasma-based electron accelerator schemes, as well as, interpretation of some astrophysical phenomena, and references, therein). From a text given in two tutorial lectures, in a limited space, we mainly focus on an important paradigm of stimulated Raman scattering.

  12. Are relativistic jets monoparametric engines?

    NASA Astrophysics Data System (ADS)

    Georganopoulos, M.; Meyer, E. T.; Fossati, G.; Lister, M. L.

    We adopt as a working hypothesis that relativistic jets are essentially mono-parametric entities, and that their physical properties are a function of a single physical parameter, the same way the physical properties of main sequence stars are mainly a function of the star mass. We propose that the physical parameter is the jet kinetic power, and we use as a proxy for this quantity the low frequency extended radio luminosity (LFERL), an orientation insensitive quantity. We discuss the consequences of this hypothesis for the collective properties of relativistic jets and we show that a blazar sequence should spontaneously emerge on the peak frequency vs luminosity plot as the locus of those sources that are well aligned to the observer's line of sight. We also show that the sources of the same LFERL should form tracks that start from a location on the blazar sequence and move to lower luminosities and peak frequencies in a way that encodes information about the emitting plasma energetics and kinematics and velocity gradients, as well as about the inverse Compton (IC) emission seed photons. We are currently working on collecting the observations that will allow us to put this idea to the test.

  13. Relativistic Definition of Spin Operators

    NASA Astrophysics Data System (ADS)

    Ryder, Lewis H.

    2002-12-01

    Some years ago Mashhoon [1] made the highly interesting suggestion that there existed a coupling of spin with rotations, just as there exists such a coupling with orbital angular momentum, as seen in the Sagnac effect, for example. Spin being essentially a quantum phenomenon, the obvious place to look for this was by studying the Dirac equation, and Hehl and Ni, in such an investigation [2], indeed found a coupling term of just the type Mashhoon had envisaged. Part of their procedure, however, was to take the nonrelativistic limit, and this was done by performing appropriate Foldy-Wouthuysen (FW) transformations. In the nonrelativistic limit, it is well-known that the spin operators for Dirac particles are in essence the Pauli matrices; but it is also well-known, and indeed was part of the motivation for Foldy and Wouthuysen's paper, that for fully-fledged Dirac particles the (4×4 generalisation of the) Pauli matrices do not yield satisfactory spin operators, since spin defined in this way would not be conserved. The question therefore presented itself: is there a relativistic spin operator for Dirac particles, such that in the relativistic, as well as the nonrelativistic, régime a Mashhoon spin-rotation coupling exists?...

  14. Four-Component Relativistic DFT Calculations of (13)C Chemical Shifts of Halogenated Natural Substances.

    PubMed

    Casella, Girolamo; Bagno, Alessandro; Komorovsky, Stanislav; Repisky, Michal; Saielli, Giacomo

    2015-12-14

    We have calculated the (13)C NMR chemical shifts of a large ensemble of halogenated organic molecules (81 molecules for a total of 250 experimental (13)C NMR data at four different levels of theory), ranging from small rigid organic compounds, used to benchmark the performance of various levels of theory, to natural substances of marine origin with conformational degrees of freedom. Carbon atoms bonded to heavy halogen atoms, particularly bromine and iodine, are known to be rather challenging when it comes to the prediction of their chemical shifts by quantum methods, due to relativistic effects. In this paper, we have applied the state-of-the-art four-component relativistic density functional theory for the prediction of such NMR properties and compared the performance with two-component and nonrelativistic methods. Our results highlight the necessity to include relativistic corrections within a four-component description for the most accurate prediction of the NMR properties of halogenated organic substances. PMID:26541625

  15. Relativistic fluids: fundamentals and recent developments

    NASA Astrophysics Data System (ADS)

    Sandoval-Villalbazo, A.; García-Perciante, A. L.

    2014-11-01

    Relativistic thermodynamics and kinetic theory have been subjects of intense research and debate recently. The topic has gained attention primarily due to its application in both astrophysical and experimental scenarios. In this talk I will review some of the challenges theorists have faced in search of a successful formalism capable of describing these systems and the alternatives proposed in order to avoid the well known instabilities and causality problems present in the first works on the subject published more than fifty years ago. Among these proposals I will focus on the first order in the gradients version of relativistic kinetic theory in order to describe special relativistic single component fluids in the presence of external forces. The main results obtained following this path will be shown including the relativistic expressions for dissipative fluxes and entropy production. Some consequences of relativistic modifications in the hydrodynamic equations will also be discussed. This work is supported by CONACyT through Grant CB2011/167563.

  16. Relativistic mixtures of charged and uncharged particles

    NASA Astrophysics Data System (ADS)

    Kremer, Gilberto M.

    2014-01-01

    Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad's moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick's law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad's distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.

  17. Electron Correlation in 4-Component Relativistic Calculations

    NASA Technical Reports Server (NTRS)

    Visscher, Luuk; Arnold, James O. (Technical Monitor)

    1994-01-01

    The full 4-component Dirac-Coulomb equation can nowadays be used in molecular calculations, The first step in solving this relativistic many-electron equation usually consists of solving the closed or open-shell Diarc-Fock equations. Like in non-relativistic calculations the outcome does not account for the effects of electron correlation. This can in principle be remedied by developing relativistic variants of electron correlation methods like Configuration Interaction or Coupled Cluster. In this talk the differences and similarities of such relativistic approaches as compared to non-relativistic methods will be reviewed. Results of Configuration Interaction calculations on the PtH molecule and on the MeF(sub 6, sup 2-) (Me= Co, Rh, Ir) complexes will be presented to give an impression of the kind of results that currently can be obtained.

  18. Relativistic electron and ion dust charging currents

    SciTech Connect

    Tribeche, Mouloud; Boukhalfa, Soufiane

    2009-09-15

    A first theoretical attempt is made to present a relativistic generalization of the well-known orbit-limited motion theory. The appropriate relativistic (electron and ion) dust charging currents are derived. The nonlinear electrostatic potential is then expressed in terms of the variable dust charge and we take advantage of this new transcendental relation to investigate briefly the effects of relativistic charge carriers. As the relativistic character of the plasma increases, it becomes evident that certain negative values of the dust charge can never be achieved as increasingly larger values of the nonlinear potential are involved. The obtained formulas bring a possibility to build theories of nonlinear collective process in relativistic dusty plasmas.

  19. Introduction of a fully relativistic capable basis set in the ab initio orthogonalized linear combination of atomic orbitals method

    NASA Astrophysics Data System (ADS)

    Thomas, Patrick Ryan

    Large simulation cell sizes, relativistic effects, and the need to correctly model excited state properties are major impediments to the accurate prediction of the optical properties of candidate materials for solid-state laser crystal and luminescent applications. To overcome these challenges, new methods must be created to improve the electron orbital wavefunction and interactions. In this work, a method has been developed to create new analytical four-component, fully-relativistic and single-component scalar relativistic descriptions of the atomic orbital wave functions from Grasp2K numerically represented atomic orbitals. In addition, adapted theory for the calculation of the relativistic kinetic energy contribution to Hamiltonian which bypasses directly solving the Dirac equation has been explicated. The orbital description improvements are tested against YAG, YBCO, SnO2 and BiF3. The improvements to the basis set reflect an improvement in both computational speed and accuracy.

  20. Toward an absolute NMR shielding scale using the spin-rotation tensor within a relativistic framework.

    PubMed

    Aucar, I Agustín; Gomez, Sergio S; Giribet, Claudia G; Aucar, Gustavo A

    2016-08-24

    One of the most influential articles showing the best way to get the absolute values of NMR magnetic shieldings, σ (non-measurables) from both accurate measurements and theoretical calculations, was published a long time ago by Flygare. His model was shown to break down when heavy atoms are involved. This fact motivated the development of new theories of nuclear spin-rotation (SR) tensors, which consider electronic relativistic effects. One was published recently by some of us. In this article we take another step further and propose three different models that generalize Flygare's model. All of them are written using four-component relativistic expressions, though the two-component relativistic SO-S term also appears in one. The first clues for these developments were built from the relationship among σ and the SR tensors within the two-component relativistic LRESC model. Besides, we had to introduce a few other well defined assumptions: (i) relativistic corrections must be included in a way to best reproduce the relationship among the (e-e) term (called "paramagnetic" within the non-relativistic domain) of σ and its equivalent part of the SR tensor, (ii) as happens in Flygare's rule, the shielding of free atoms shall be included to improve accuracy. In the highest accurate model, a new term known as Spin-orbit due to spin, SO-S (in this mechanism the spin-Zeeman Hamiltonian replaces the orbital-Zeeman Hamiltonian), is included. We show the results of the application of those models to halogen containing linear molecules. PMID:27506822

  1. High Resolution Simulations of Relativistic Hydrodynamic and MHD Turbulence

    NASA Astrophysics Data System (ADS)

    Zrake, Jonathan; MacFadyen, A.

    2013-01-01

    We present a program of simulations designed to investigate the basic properties of relativistic hydrodynamic and magnetohydrodynamic (MHD) turbulence. We employ a well-tested 5th-order accurate numerical scheme at resolutions of up to 2048^3 zones for hydrodynamic turbulence, and a minimally diffusive 2nd-order scheme at resolutions of up to 1024^3 in the case of relativistic MHD. For the hydrodynamic case, we simulate a relativistically hot gas in a cubic periodic domain continuously driven at large scales with Lorentz factor of about 3. We find that relativistic turbulent velocity fluctuations with Γ β > 1 persist from the driving scale down to scales an order of magnitude smaller, demonstrating the existence of a sustained relativistic turbulent cascade. The power spectrum of the fluid 4-velocity is broadly Kolmogorov-like, roughly obeying a power law with 5/3 index between scales 1/10 and 1/100 of the domain. Departures from 5/3 scaling are larger for the power spectrum of 3-velocity. We find that throughout the inertial interval, 25% of power is in dilatational modes, which obey strict power law scaling between 1/2 and 1/100 of the domain with an index of 1.88. Our program also explores turbulent amplification of magnetic fields in the conditions of merging neutron stars, using a realistic equation of state for dense nuclear matter (ρ ˜ 10^13 g/cm^3). We find that very robustly, seed fields are amplified to magnetar strength (≥ 4 * 10^16 Gauss) within ˜1 micro-second for fluid volumes near the size of the NS crust thickness <10 meters. We present power spectra of the kinetic and magnetic energy taken long into the fully stationary evolution of the highest resolution models, finding the magnetic energy to be in super-equipartition (4 times larger) with the kinetic energy through the inertial range. We believe that current global simulations of merging NS binaries are insufficiently resolved for studying field amplification via turbulent processes

  2. Relativistic contributions to single and double core electron ionization energies of noble gases

    SciTech Connect

    Niskanen, J.; Norman, P.; Aksela, H.; Aagren, H.

    2011-08-07

    We have performed relativistic calculations of single and double core 1s hole states of the noble gas atoms in order to explore the relativistic corrections and their additivity to the ionization potentials. Our study unravels the interplay of progression of relaxation, dominating in the single and double ionization potentials of the light elements, versus relativistic one-electron effects and quantum electrodynamic effects, which dominate toward the heavy end. The degree of direct relative additivity of the relativistic corrections for the single electron ionization potentials to the double electron ionization potentials is found to gradually improve toward the heavy elements. The Dirac-Coulomb Hamiltonian is found to predict a scaling ratio of {approx}4 for the relaxation induced relativistic energies between double and single ionization. Z-scaling of the computed quantities were obtained by fitting to power law. The effects of nuclear size and form were also investigated and found to be small. The results indicate that accurate predictions of double core hole ionization potentials can now be made for elements across the full periodic table.

  3. Gauge origin independent calculations of molecular magnetisabilities in relativistic four-component theory

    NASA Astrophysics Data System (ADS)

    Iliaš, Miroslav; Jensen, Hans Jørgen Aa.; Bast, Radovan; Saue, Trond

    2013-07-01

    The use of magnetic-field dependent London atomic orbitals, also called gauge including atomic orbitals, is known to be an efficient choice for accurate non-relativistic calculations of magnetisabilities. In this work, the appropriate formulas were extended and implemented in the framework of the four-component relativistic linear response method at the self-consistent field single reference level. Benefits of employing the London atomic orbitals in relativistic calculations are illustrated with Hartree-Fock wave functions on the XF3 (X = N, P, As, Sb, Bi) series of molecules. Significantly better convergence of magnetisabilities with respect to the basis set size is observed compared to calculations employing a common gauge origin. In fact, it is mandatory to use London atomic orbitals unless you want to use ridiculously large basis sets. Relativistic effects on magnetisabilities are found to be quite small (<5%) for this particular set of molecules, but should be investigated on a larger set of molecules. We emphasise the breakdown of the connection between the paramagnetic contribution to magnetisabilities and rotational g tensors in the relativistic domain and discuss its origin. Finally, we visualise the magnetisability density which shows markedly atomic features evocative of Pascal's rules.

  4. Charm physics with a nonperturbatively determined relativistic heavy quark action

    NASA Astrophysics Data System (ADS)

    Lin, Huey-Wen

    We explore the methodology of a nonperturbative approach on the lattice to heavy quark calculations. We discuss the application of the regularization-independent (RI) scheme of Rome/Southampton to determining the normalization of heavy quark operators nonperturbatively using the Fermilab action. We study the fermion action needed to accurately describe the low-energy physics of systems including heavy quarks in lattice QCD, even when the heavy fermion mass m is on the order of, or larger than, the inverse lattice spacing: m ≥ 1/a. We carry out an expansion through first order in | p⃗ |a and all orders in ma, refining the analysis of the Fermilab and Tsukuba groups. We demonstrate that the spectrum of heavy quark bound states can be determined accurately through | p⃗ |a and (ma)n for arbitrary exponent n by using a lattice action containing only three unknown coefficients: m0, zeta and cP (a generalization of cSW), which are functions of ma. We propose to determine the coefficients of the relativistic heavy quark action by matching the finite-volume on-shell spectrum with one determined in an exact relativistic theory. The matching relativistic amplitudes may be determined from finite-volume step-scaling recursion. The results will be presented from a step-scaling determination of the coefficients in the relativistic heavy quark action. By matching finite-volume heavy-heavy and heavy-light meson masses, we attempt to determine the three parameters ( m0, zeta, cP) in the on-shell-improved heavy quark action. These calculations are carried out on 163 and 243 spatial volumes for a heavy quark mass approximately that of the charm quark. We use nonperturbative coefficients obtained from the step-scaling method to calculate the charmed meson spectrum on 243, a -1 = 2.4 GeV lattices. The charmonium state masses, including radial excited states, are in reasonable agreement with the experimentally observed spectrum. We find the hyperfine splitting is 77.8(15) MeV with

  5. Relativistic effects in Lyman-α forest

    NASA Astrophysics Data System (ADS)

    Iršič, Vid; Di Dio, Enea; Viel, Matteo

    2016-02-01

    We present the calculation of the Lyman-alpha (Lyman-α) transmitted flux fluctuations with full relativistic corrections to the first order. Even though several studies exist on relativistic effects in galaxy clustering, this is the first study to extend the formalism to a different tracer of underlying matter at unique redshift range (z=2-5). Furthermore, we show a comprehensive application of our calculations to the Quasar-Lyman-α cross-correlation function. Our results indicate that the signal of relativistic effects are sizeable at Baryonic Acoustic Oscillation (BAO) scale mainly due to the large differences in density bias factors of our tracers. We construct an observable, the anti-symmetric part of the cross-correlation function, that is dominated by the relativistic signal and offers a new way to measure the relativistic terms at relatively small scales. The analysis shows that relativistic effects are important when considering cross-correlations between tracers with very different biases, and should be included in the data analysis of the current and future surveys. Moreover, the idea presented in this paper is highly complementary to other techniques and observables trying to isolate the effect of the relativistic corrections and thus test the validity of the theory of gravity beyond the Newtonian regime.

  6. Optics in the Relativistic Regime

    NASA Astrophysics Data System (ADS)

    Tajima, Toshiki

    2012-06-01

    Optics has extended the frontier of low energy physics. Here we present the progress in the opposite direction of relativistic intensity regime of optics. With intense and large energy laser, particles may be accelerated to high energies via laser wakefield acceleration (Tajima and Dawson, 1979) over a compact distance orders of magnitude shorter than the RF approach. We should be able to accelerate electrons (over 30m) and ions (over cm) toward TeV with an existing kJ laser. We can check Lorentz invariance in the ultrarelativistic regime. Further, laser allows us to explore the presence of weakly coupling fields such as Dark Matter and Dark Energy with an unprecedented sensitivity. We call this emerging capability as the Laser Particle Physics Paradigm (LP^3).

  7. 3-D Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Nishikawa, K.-I.; Frank, J.; Koide, S.; Sakai, J.-I.; Christodoulou, D. M.; Sol, H.; Mutel, R. L.

    1998-12-01

    We present 3-D numerical simulations of moderately hot, supersonic jets propagating initially along or obliquely to the field lines of a denser magnetized background medium with Lorentz factors of W = 4.56 and evolving in a four-dimensional spacetime. The new results are understood as follows: Relativistic simulations have consistently shown that these jets are effectively heavy and so they do not suffer substantial momentum losses and are not decelerated as efficiently as their nonrelativistic counterparts. In addition, the ambient magnetic field, however strong, can be pushed aside with relative ease by the beam, provided that the degrees of freedom associated with all three spatial dimensions are followed self-consistently in the simulations. This effect is analogous to pushing Japanese ``noren'' or vertical Venetian blinds out of the way while the slats are allowed to bend in 3-D space rather than as a 2-D slab structure.

  8. Invisibility cloaks in relativistic motion

    NASA Astrophysics Data System (ADS)

    Halimeh, Jad C.; Thompson, Robert T.; Wegener, Martin

    2016-01-01

    We consider an ideal invisibility cloak which is illuminated by monochromatic light and which moves in vacuum at constant relativistic velocity with respect to the common inertial frame of light source and observer. We show that, in general, the moving cloak becomes detectable by image distortions and by generating a broad frequency spectrum of the scattered light. However, for many special combinations of incident light frequency, wave vector of light, and cloak velocity, ideal cloaking remains possible. It becomes nonreciprocal though. This means that light rays emitted by the light source arrive at the observer as though they have traveled through vacuum, but they take completely different paths after being retroreflected at the observer position.

  9. Relativistic recoil and the railgun

    NASA Astrophysics Data System (ADS)

    Allen, J. E.; Jones, T. V.

    1990-01-01

    Calculations are presented that refute recent statements (e.g., Graneau, 1987) made to the effect that the operation of a railgun cannot be explained in terms of classical relativistic electrodynamics. It is demonstrated that, on the contrary, there is no difficulty in using the concept of electromagnetic momentum to calculate the electromagnetic forces that propel the projectile in a railgun. The error made by other authors was to suppose that classical electrodynamics demand that a large amount of momentum be associated with the electromagnetic field at some previous time. The projectile can acquire much more momentum than that associated with the incident wave, because the electromagnetic waves are reflected both at the projectile end and at the breech end of the railgun.

  10. Landau damping in relativistic plasmas

    NASA Astrophysics Data System (ADS)

    Young, Brent

    2016-02-01

    We examine the phenomenon of Landau damping in relativistic plasmas via a study of the relativistic Vlasov-Poisson (rVP) system on the torus for initial data sufficiently close to a spatially uniform steady state. We find that if the steady state is regular enough (essentially in a Gevrey class of degree in a specified range) and if the deviation of the initial data from this steady state is small enough in a certain norm, the evolution of the system is such that its spatial density approaches a uniform constant value quasi-exponentially fast (i.e., like exp ( - C |" separators=" t | ν ¯ ) for ν ¯ ∈ ( 0 , 1 ) ). We take as a priori assumptions that solutions launched by such initial data exist for all times (by no means guaranteed with rVP, but a reasonable assumption since we are close to a spatially uniform state) and that the various norms in question are continuous in time (which should be a consequence of an abstract version of the Cauchy-Kovalevskaya theorem). In addition, we must assume a kind of "reverse Poincaré inequality" on the Fourier transform of the solution. In spirit, this assumption amounts to the requirement that there exists 0 < ϰ < 1 so that the mass in the annulus ϰ ≤ |" separators=" v | < 1 for the solution launched by the initial data is uniformly small for all t. Typical velocity bounds for solutions to rVP launched by small initial data (at least on ℝ6) imply this bound. We note that none of our results require spherical symmetry (a crucial assumption for many current results on rVP).

  11. Localization scheme for relativistic spinors

    NASA Astrophysics Data System (ADS)

    Ciupka, J.; Hanrath, M.; Dolg, M.

    2011-12-01

    A new method to determine localized complex-valued one-electron functions in the occupied space is presented. The approach allows the calculation of localized orbitals regardless of their structure and of the entries in the spinor coefficient matrix, i.e., one-, two-, and four-component Kramers-restricted or unrestricted one-electron functions with real or complex expansion coefficients. The method is applicable to localization schemes that maximize (or minimize) a functional of the occupied spinors and that use a localization operator for which a matrix representation is available. The approach relies on the approximate joint diagonalization (AJD) of several Hermitian (symmetric) matrices which is utilized in electronic signal processing. The use of AJD in this approach has the advantage that it allows a reformulation of the localization criterion on an iterative 2 × 2 pair rotating basis in an analytical closed form which has not yet been described in the literature for multi-component (complex-valued) spinors. For the one-component case, the approach delivers the same Foster-Boys or Pipek-Mezey localized orbitals that one obtains from standard quantum chemical software, whereas in the multi-component case complex-valued spinors satisfying the selected localization criterion are obtained. These localized spinors allow the formulation of local correlation methods in a multi-component relativistic framework, which was not yet available. As an example, several heavy and super-heavy element systems are calculated using a Kramers-restricted self-consistent field and relativistic two-component pseudopotentials in order to investigate the effect of spin-orbit coupling on localization.

  12. Search for a Lorentz invariant velocity distribution of a relativistic gas

    NASA Astrophysics Data System (ADS)

    Curado, Evaldo M. F.; Germani, Felipe T. L.; Soares, Ivano Damião

    2016-02-01

    We examine the problem of the relativistic velocity distribution in a 1-dim relativistic gas in thermal equilibrium. We use numerical simulations of the relativistic molecular dynamics for a gas with two components, light and heavy particles. However in order to obtain the numerical data our treatment distinguishes two approaches in the construction of the histograms for the same relativistic molecular dynamic simulations. The first, largely considered in the literature, consists in constructing histograms with constant bins in the velocity variable and the second consists in constructing histograms with constant bins in the rapidity variable which yields Lorentz invariant histograms, contrary to the first approach. For histograms with constant bins in the velocity variable the numerical data are fitted accurately by the Jüttner distribution which is also not Lorentz invariant. On the other hand, the numerical data obtained from histograms constructed with constant bins in the rapidity variable, which are Lorentz invariant, are accurately fitted by a Lorentz invariant distribution whose derivation is discussed in this paper. The histograms thus constructed are not fitted by the Jütter distribution (as they should not). Our derivation is based on the special theory of relativity, the central limit theorem and the Lobachevsky structure of the velocity space of the theory, where the rapidity variable plays a crucial role. For v2 /c2 ≪ 1 and 1 / β ≡kB T /m0c2 ≪ 1 the distribution tends to the Maxwell-Boltzmann distribution.

  13. Relativistic Theory of Few Body Systems

    SciTech Connect

    Franz Gross

    2002-11-01

    Very significant advances have been made in the relativistic theory of few body systems since I visited Peter Sauer and his group in Hannover in 1983. This talk provides an opportunity to review the progress in this field since then. Different methods for the relativistic calculation of few nucleon systems are briefly described. As an example, seven relativistic calculations of the deuteron elastic structure functions, A, B, and T{sub 20}, are compared. The covariant SPECTATOR {copyright} theory, among the more successful and complete of these methods, is described in more detail.

  14. Momentum relaxation of a relativistic Brownian particle.

    PubMed

    Felderhof, B U

    2012-12-01

    The momentum relaxation of a relativistic Brownian particle immersed in a fluid is studied on the basis of the Fokker-Planck equation for the relativistic Ornstein-Uhlenbeck process. An analytical expression is derived for the short-time relaxation rate. The relaxation spectrum has both discrete and continuum components. It is shown that the Fokker-Planck equation under consideration is closely related to the Schrödinger equation for the hydrogen atom. Hence it follows that there is an infinite number of discrete states. The momentum autocorrelation function is calculated numerically for a strongly relativistic particle. PMID:23367889

  15. Relativistic scattered wave calculations on UF6

    NASA Technical Reports Server (NTRS)

    Case, D. A.; Yang, C. Y.

    1980-01-01

    Self-consistent Dirac-Slater multiple scattering calculations are presented for UF6. The results are compared critically to other relativistic calculations, showing that the results of all molecular orbital calculations are in qualitative agreement, as measured by energy levels, population analyses, and spin-orbit splittings. A detailed comparison is made to the relativistic X alpha(RX alpha) method of Wood and Boring, which also uses multiple scattering theory, but incorporates relativistic effects in a more approximate fashion. For the most part, the RX alpha results are in agreement with the present results.

  16. Forced Turbulence in Relativistic Conformal Fluids

    NASA Astrophysics Data System (ADS)

    Westernacher-Schneider, John Ryan; Green, Stephen; Lehner, Luis; Canon, Kipp; Oz, Yaron

    2015-04-01

    Given the renewed interest arising both from AdS/CFT and astrophysics, we revisit the phenomenon of relativistic turbulence. We build on some recent work which extends known non-relativistic results in turbulence to the case of relativistic (and thus compressible) fluids. In particular, we derive the scaling behaviour of two-point correlation functions in 2+1 dimensions--holographically dual to 3+1 dimensional gravity. Turbulence in 2+1 dimensions also approximates several astrophysical situations, such as thin accretion disks around black holes. We perform numerical simulations of forced steady-state turbulence to verify our derived correlation functions.

  17. Relativistic corrections to the triton binding energy

    SciTech Connect

    Sammarruca, F.; Xu, D.P.; Machleidt, R. )

    1992-11-01

    The influence of relativity on the triton binding energy is investigated. The relativistic three-dimensional version of the Bethe-Salpeter equation proposed by Blankenbecler and Sugar (BbS) is used. Relativistic (nonseparable) one-boson-exchange potentials (constructed in the BbS framework) are employed for the two-nucleon interaction. In a 34-channel Faddeev calculation, it is found that relativistic effects increase the triton binding energy by about 0.2 MeV. Including charge dependence (besides relativity), the final triton binding energy predictions are 8.33 and 8.16 MeV for the Bonn A and B potentials, respectively.

  18. Relativistic klystron research for linear colliders

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Koontz, R.F.

    1988-09-01

    Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron-positron colliders, compact accelerators, and FEL sources. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our relativistic klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 9 figs., 1 tab.

  19. Relativistic quantum mechanics and relativistic entanglement in the rest-frame instant form of dynamics

    SciTech Connect

    Alba, David; Crater, Horace W.; Lusanna, Luca

    2011-06-15

    A new formulation of relativistic quantum mechanics is proposed in the framework of the rest-frame instant form of dynamics, where the world-lines of the particles are parametrized in terms of the Fokker-Pryce center of inertia and of Wigner-covariant relative 3-coordinates inside the instantaneous Wigner 3-spaces, and where there is a decoupled (non-covariant and non-local) canonical relativistic center of mass. This approach: (a) allows us to make a consistent quantization in every inertial frame; (b) leads to a description of both bound and scattering states; (c) offers new insights on the relativistic localization problem; (d) leads to a non-relativistic limit with a Hamilton-Jacobi treatment of the Newton center of mass; (e) clarifies non-local aspects (spatial non-separability) of relativistic entanglement connected with Lorentz signature and not present in its non-relativistic treatment.

  20. Relativistic Effects in Two Photon Decay of 0-+ Quarkonium

    NASA Astrophysics Data System (ADS)

    Zhou, H. Q.; Zou, B. S.

    Relativistic effects in two photon decay of 0-+ quarkonium are investigated with a relativistic phenomenological approach. Comparing with the non-relativistic approximation, the relativistic phenomenological approach gives corrections coming from three sources: qbar q relative momentum distribution, qbar q relative energy distribution and description of quark spinors in the meson. These relativistic effects are studied in detail for cbar c and sbar s systems.

  1. Relativistic Electron-Electron Bremsstrahlung in Fusion Plasma

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Jia; Kawai, Norio; Kawamura, Takaichi; Maegauchi, Tetsuo; Narumi, Hajime

    1982-05-01

    Transition matrices and differential cross sections for electron-electron bremsstrahlung in relativistic energy region are calculated by the lowest-order perturbation theory of quantum electrodynamics. The bremsstrahlung spectra and emission rates are evaluated for relativistic Maxwellian plasma. The results are discussed in comparison with those obtained by non-relativistic and extreme-relativistic approximations and it is noted that the relativistic effect becomes appreciable above the order of 10 keV for the electron temperature.

  2. RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code

    SciTech Connect

    Zhang, Wei-Qun; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study

    2005-06-06

    The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.

  3. Coherent states for the relativistic harmonic oscillator

    NASA Technical Reports Server (NTRS)

    Aldaya, Victor; Guerrero, J.

    1995-01-01

    Recently we have obtained, on the basis of a group approach to quantization, a Bargmann-Fock-like realization of the Relativistic Harmonic Oscillator as well as a generalized Bargmann transform relating fock wave functions and a set of relativistic Hermite polynomials. Nevertheless, the relativistic creation and annihilation operators satisfy typical relativistic commutation relations of the Lie product (vector-z, vector-z(sup dagger)) approximately equals Energy (an SL(2,R) algebra). Here we find higher-order polarization operators on the SL(2,R) group, providing canonical creation and annihilation operators satisfying the Lie product (vector-a, vector-a(sup dagger)) = identity vector 1, the eigenstates of which are 'true' coherent states.

  4. Relativistic plasma astrophysics with intense lasers

    NASA Astrophysics Data System (ADS)

    Kuramitsu, Yasuhiro; Chu, Hsu-Hsin; Hau, Lin-Ni; Chen, Shih-Hung; Liu, Yao-Li; Hsieh, Chia-Ying; Sakawa, Youichi; Hideaki, Takabe; Wang, Jyhpyng

    2015-12-01

    Recent progresses of laser technologies enable us to investigate space and astrophysical phenomena in laboratories. In space plasmas the local observations by spacecrafts provide us the microscopic information of the plasma and electric/magnetic fields, however, it is difficult to obtain the global structures of the phenomena. In astrophysical plasmas, in contrast, global images provide us the macroscopic information, although there is no local observation and thus no microscopic information. Laboratory experiments on space and astrophysical phenomena provide us the local and global information simultaneously. We have investigated so far mostly non-relativistic phenomena in the universe with long laser pulses. Now we extend our research from non-relativistic to relativistic regime with an ultra intense laser, the 100 TW laser facility at National Central University. We introduce our facility and model relativistic phenomena in laboratory, focusing on the magnetic field generation and the magnetic reconnection in the universe.

  5. Hot relativistic winds and the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Fujimura, F. S.; Kennel, C. F.

    1981-01-01

    Efforts to formulate a self-consistent model of pulsar magnetospheres which links the particle source near the pulsar to the outflowing relativistic wind and couples the wind to the surrounding nebula are reviewed. The use of a relativistic MHD wind is recommended to account for global photon emission and the invisibility of the method of plasma transport. Consideration of a magnetic monopole relativistic wind due to an axially symmetric aligned rotator is combined with calculations of the initial velocity of the wind to show that the flow velocity in such a model will never exceed Mach 1. Extending the solution to the case of a hot relativistic wind at supersonic speeds is noted to yield results consistent with observations of the Crab Nebula

  6. Electromagnetic processes in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Bertulani, C. A.; Baur, G.

    1986-10-01

    Electromagnetic effects in relativistic heavy ion collisions with impact parameter larger than the sum of the nuclear radii are studied using the virtual photon method. With increasing value of the relativistic parameter γ the hardness of the virtual photon spectrum increases. This leads to interesting new effects which will also have to be considered in the design of future relativistic heavy ion machines and experiments. The excitation of high-lying giant E1 and E2 multipole resonances is calculated as well as electromagnetic pion production. Coulomb bremsstrahlung is calculated and compared to the bremsstrahlung emitted in the more violent central nuclear collisions. K-shell ionization and electron-positron pair production is studied. The latter process has a very large cross section for heavy ions and contributes significantly to the stopping power of relativistic heavy ions in a dense medium.

  7. Quantum probability assignment limited by relativistic causality.

    PubMed

    Han, Yeong Deok; Choi, Taeseung

    2016-01-01

    Quantum theory has nonlocal correlations, which bothered Einstein, but found to satisfy relativistic causality. Correlation for a shared quantum state manifests itself, in the standard quantum framework, by joint probability distributions that can be obtained by applying state reduction and probability assignment that is called Born rule. Quantum correlations, which show nonlocality when the shared state has an entanglement, can be changed if we apply different probability assignment rule. As a result, the amount of nonlocality in quantum correlation will be changed. The issue is whether the change of the rule of quantum probability assignment breaks relativistic causality. We have shown that Born rule on quantum measurement is derived by requiring relativistic causality condition. This shows how the relativistic causality limits the upper bound of quantum nonlocality through quantum probability assignment. PMID:26971717

  8. Pseudospectral approach to relativistic molecular theory.

    PubMed

    Nakajima, Takahito; Hirao, Kimihiko

    2004-08-22

    The efficient relativistic Dirac-Hartree-Fock (DHF) and Dirac-Kohn-Sham (DKS) methods are proposed by an application of the pseudospectral (PS) approach. The present PS-DHF/DKS method is a relativistic extension of the PS-HF/KS method of Friesner, though we aim at higher numerical accuracy by elimination of superfluous arbitrariness. The relativistic PS-DHF/DKS method is implemented into our REL4D programs. Several PS applications to molecular systems show that the relativistic PS-DHF/DKS approach is more efficient than the traditional approach without a loss of accuracy. The present PS-DKS method successfully assigns and predicts the photoelectron spectra of hexacarbonyl complexes of tungsten and seaborgium theoretically. PMID:15303907

  9. Relativistic Thomson Scatter from Factor Calculation

    2009-11-01

    The purpose of this program is calculate the fully relativistic Thomson scatter from factor in unmagnetized plasmas. Such calculations are compared to experimental diagnoses of plasmas at such facilities as the Jupiter laser facility here a LLNL.

  10. Quantum probability assignment limited by relativistic causality

    PubMed Central

    Han, Yeong Deok; Choi, Taeseung

    2016-01-01

    Quantum theory has nonlocal correlations, which bothered Einstein, but found to satisfy relativistic causality. Correlation for a shared quantum state manifests itself, in the standard quantum framework, by joint probability distributions that can be obtained by applying state reduction and probability assignment that is called Born rule. Quantum correlations, which show nonlocality when the shared state has an entanglement, can be changed if we apply different probability assignment rule. As a result, the amount of nonlocality in quantum correlation will be changed. The issue is whether the change of the rule of quantum probability assignment breaks relativistic causality. We have shown that Born rule on quantum measurement is derived by requiring relativistic causality condition. This shows how the relativistic causality limits the upper bound of quantum nonlocality through quantum probability assignment. PMID:26971717

  11. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-12-31

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  12. Relativistic projection and boost of solitons

    SciTech Connect

    Wilets, L.

    1991-01-01

    This report discusses the following topics on the relativistic projection and boost of solitons: The center of mass problem; momentum eigenstates; variation after projection; and the nucleon as a composite. (LSP).

  13. Relativistic particle acceleration in plerions

    NASA Technical Reports Server (NTRS)

    Arons, Jonathan; Tavani, Marco

    1994-01-01

    We discuss recent research on the structure and particle acceleration properties of relativistic shock waves in which the magnetic field is transverse to the flow direction in the upstream medium, and whose composition is either pure electrons and positrons or primarily electrons and positrons with an admixture of heavy ions. Particle-in-cell simulation techniques as well as analytic theory have been used to show that such shocks in pure pair plasmas are fully thermalized -- the downstream particle spectra are relativistic Maxwellians at the temperature expected from the jump conditions. On the other hand, shocks containing heavy ions which are a minority constituent by number but which carry most of the energy density in the upstream medium do put approximately 20% of the flow energy into a nonthermal population of pairs downstream, whose distribution in energy space is N(E) varies as E(exp -2), where N(E)dE is the number of particles with energy between E and E+dE. The mechanism of thermalization and particle acceleration is found to be synchrotron maser activity in the shock front, stimulated by the quasi-coherent gyration of the whole particle population as the plasma flowing into the shock reflects from the magnetic field in the shock front. The synchrotron maser modes radiated by the heavy ions are absorbed by the pairs at their (relativistic) cyclotron frequencies, allowing the maximum energy achievable by the pairs to be gamma(sub +/-)m(sub +/-)c squared = m(sub i)c squared gamma(sub 1)/Z(sub i), where gamma(sub 1) is the Lorentz factor of the upstream flow and Z(sub i) is the atomic number of the ions. The shock's spatial structure is shown to contain a series of 'overshoots' in the magnetic field, regions where the gyrating heavy ions compress the magnetic field to levels in excess of the eventual downstream value. This shock model is applied to an interpretation of the structure of the inner regions of the Crab Nebula, in particular to the 'wisps

  14. Relativistic diffusive motion in random electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2011-08-01

    We show that the relativistic dynamics in a Gaussian random electromagnetic field can be approximated by the relativistic diffusion of Schay and Dudley. Lorentz invariant dynamics in the proper time leads to the diffusion in the proper time. The dynamics in the laboratory time gives the diffusive transport equation corresponding to the Jüttner equilibrium at the inverse temperature β-1 = mc2. The diffusion constant is expressed by the field strength correlation function (Kubo's formula).

  15. On the convexity of relativistic hydrodynamics

    NASA Astrophysics Data System (ADS)

    Ibáñez, José M.; Cordero-Carrión, Isabel; Martí, José M.; Miralles, Juan A.

    2013-03-01

    The relativistic hydrodynamic system of equations for a perfect fluid obeying a causal equation of state is hyperbolic (Anile 1989 Relativistic Fluids and Magneto-Fluids (Cambridge: Cambridge University Press)). In this report, we derive the conditions for this system to be convex in terms of the fundamental derivative of the equation of state (Menikoff and Plohr1989 Rev. Mod. Phys. 61 75). The classical limit is recovered. Communicated by L Rezzolla

  16. Modulational instabilities in relativistic pair plasmas

    NASA Astrophysics Data System (ADS)

    Mendonça, J. T.

    2016-05-01

    We study the modulational instability of an intense photon beam in a relativistic pair plasma. We use the wave-kinetic description of the photon field and relativistic fluid equations for electrons and positrons. This allows us to consider the influence of the photon spectral distribution and photon recoil effects on the instability threshold and growth rates. The case of very low frequencies modulations, well below plasma frequency, is compared to that of high-frequency modulations corresponding to the plasmon decay instability.

  17. Recording of relativistic particles in thin scintillators

    SciTech Connect

    Tolstukhin, I A.; Somov, Alexander S.; Somov, S. V.; Bolozdynya, A. I.

    2014-11-01

    Results of investigating an assembly of thin scintillators and silicon photomultipliers for registering relativistic particles with the minimum ionization are presented. A high efficiency of registering relativistic particles using an Ej-212 plastic scintillator, BSF-91A wavelength-shifting fiber (Saint-Gobain), and a silicon photomultiplier (Hamamtsu) is shown. The measurement results are used for creating a scintillation hodoscope of the magnetic spectrometer for registering γ quanta in the GlueX experiment.

  18. Relativistic klystron research at SLAC and LLNL

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Morton, P.L.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Schwarz, H.D.; Takeuchi, Y.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B.; Hopkins, D.B.; Sessler, A.M.; Barletta, W.A.; Birx, D.L.; Boyd, J.K.; Houck, T.; Westenskow, G.A.; Yu, S.S.

    1988-06-01

    We are developing relativistic klystrons as a power source for high gradient accelerator applications such as large linear electron-positron colliders and compact accelerators. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here briefly on our experiments so far. 5 refs., 1 fig., 1 tab.

  19. Relativistic particle beams for interstellar propulsion

    NASA Astrophysics Data System (ADS)

    Nordley, Gerald D.

    1993-04-01

    The concept of pellet-stream propulsion proposed by Singer (1980) is extended to particle beams and relativistic velocities. A simple relativistic mission study is presented, and it is shown how certain technological developments might enhance the concept. In particular, considerations discussed include beam drivers; beam cooling, steering, and focusing; beam driven mission mechanics; and the radiation problem. The energy issues are also briefly considered.

  20. Relativistic corrections to the ground-state energy of the positronium molecule

    SciTech Connect

    Bubin, Sergiy; Stanke, Monika; Kedziera, Dariusz; Adamowicz, Ludwik

    2007-06-15

    The leading-order relativistic corrections to the ground-state energy of the positronium molecule (Ps{sub 2}) have been computed within the framework of perturbation theory. As the zero-order wave function we used a highly accurate nonrelativistic variational expansion in terms of 6000 explicitly correlated Gaussians that yielded the lowest variational upper bound for this system to date. We also report some expectation values representing the properties of Ps{sub 2}.

  1. Entropy current for non-relativistic fluid

    NASA Astrophysics Data System (ADS)

    Banerjee, Nabamita; Dutta, Suvankar; Jain, Akash; Roychowdhury, Dibakar

    2014-08-01

    We study transport properties of a parity-odd, non-relativistic charged fluid in presence of background electric and magnetic fields. To obtain stress tensor and charged current for the non-relativistic system we start with the most generic relativistic fluid, living in one higher dimension and reduce the constituent equations along the light-cone direction. We also reduce the equation satisfied by the entropy current of the relativistic theory and obtain a consistent entropy current for the non-relativistic system (we call it "canonical form" of the entropy current). Demanding that the non-relativistic fluid satisfies the second law of thermodynamics we impose constraints on various first order transport coefficients. For parity even fluid, this is straight forward; it tells us positive definiteness of different transport coefficients like viscosity, thermal conductivity, electric conductivity etc. However for parity-odd fluid, canonical form of the entropy current fails to confirm the second law of thermodynamics. Therefore, we need to add two parity-odd vectors to the entropy current with arbitrary coefficients. Upon demanding the validity of second law, we see that one can fix these two coefficients exactly.

  2. Predict amine solution properties accurately

    SciTech Connect

    Cheng, S.; Meisen, A.; Chakma, A.

    1996-02-01

    Improved process design begins with using accurate physical property data. Especially in the preliminary design stage, physical property data such as density viscosity, thermal conductivity and specific heat can affect the overall performance of absorbers, heat exchangers, reboilers and pump. These properties can also influence temperature profiles in heat transfer equipment and thus control or affect the rate of amine breakdown. Aqueous-amine solution physical property data are available in graphical form. However, it is not convenient to use with computer-based calculations. Developed equations allow improved correlations of derived physical property estimates with published data. Expressions are given which can be used to estimate physical properties of methyldiethanolamine (MDEA), monoethanolamine (MEA) and diglycolamine (DGA) solutions.

  3. Accurate thickness measurement of graphene

    NASA Astrophysics Data System (ADS)

    Shearer, Cameron J.; Slattery, Ashley D.; Stapleton, Andrew J.; Shapter, Joseph G.; Gibson, Christopher T.

    2016-03-01

    Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.

  4. The Relativistic Heavy Ion Collider

    NASA Astrophysics Data System (ADS)

    Fischer, Wolfram

    The Relativistic Heavy Ion Collider (RHIC), shown in Fig. 1, was build to study the interactions of quarks and gluons at high energies [Harrison, Ludlam and Ozaki (2003)]. The theory of Quantum Chromodynamics (QCD) describes these interactions. One of the main goals for the RHIC experiments was the creation and study of the Quark-Gluon Plasma (QGP), which was expected to be formed after the collision of heavy ions at a temperature of approximately 2 trillion kelvin (or equivalently an energy of 150 MeV). The QGP is the substance which existed only a few microseconds after the Big Bang. The QGP was anticipated to be weakly interacting like a gas but turned out to be strongly interacting and more like a liquid. Among its unusual properties is its extremely low viscosity [Auerbach and Schlomo (2009)], which makes the QGP the substance closest to a perfect liquid known to date. The QGP is opaque to moderate energy quarks and gluons leading to a phenomenon called jet quenching, where of a jet and its recoil jet only one is observable and the other suppressed after traversing and interacting with the QGP [Jacak and Müller (2012)]...

  5. Detonation waves in relativistic hydrodynamics

    SciTech Connect

    Cissoko, M. )

    1992-02-15

    This paper is concerned with an algebraic study of the equations of detonation waves in relativistic hydrodynamics taking into account the pressure and the energy of thermal radiation. A new approach to shock and detonation wavefronts is outlined. The fluid under consideration is assumed to be perfect (nonviscous and nonconducting) and to obey the following equation of state: {ital p}=({gamma}{minus}1){rho} where {ital p}, {rho}, and {gamma} are the pressure, the total energy density, and the adiabatic index, respectively. The solutions of the equations of detonation waves are reduced to the problem of finding physically acceptable roots of a quadratic polynomial {Pi}({ital X}) where {ital X} is the ratio {tau}/{tau}{sub 0} of dynamical volumes behind and ahead of the detonation wave. The existence and the locations of zeros of this polynomial allow it to be shown that if the equation of state of the burnt fluid is known then the variables characterizing the unburnt fluid obey well-defined physical relations.

  6. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    SciTech Connect

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

    Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.

  7. Relativistic Dipole Matrix Element Zeros

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2002-05-01

    There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ω , only depend on the bound state l quantum number according to ω^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (ɛ , l_b+1,j_b) transitions such as ns_1/2arrow ɛ p_1/2; np_3/2arrow ɛ d_3/2: nd_5/2arrow ɛ f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |κ | is substituted for γ in analytic expressions for matrix elements, the zeros remain, but ω^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ω mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).

  8. Glimm's Method for Relativistic Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Cannizzo, J. K.; Gehrels, N.; Vishniac, E. T.

    2008-06-01

    We present the results of standard one-dimensional test problems in relativistic hydrodynamics using Glimm's (random choice) method and compare them to results obtained using finite differencing methods. For problems containing profiles with sharp edges, such as shocks, we find Glimm's method yields global errors ~1-3 orders of magnitude smaller than the traditional techniques. The strongest differences are seen for problems in which a shear field is superposed. For smooth flows, Glimm's method is inferior to standard methods. The location of specific features can be off by up to two grid points with respect to an exact solution in Glimm's method, and furthermore, curved states are not modeled optimally, since the method idealizes solutions as being composed of piecewise constant states. Thus, although Glimm's method is superior at correctly resolving sharp features, especially in the presence of shear, for realistic applications in which one typically finds smooth flows plus strong gradients or discontinuities, standard finite-difference methods yield smaller global errors. Glimm's method may prove useful in certain applications such as GRB afterglow shock propagation into a uniform medium.

  9. Stopping of relativistic electrons in a partially degenerate electron fluid.

    PubMed

    Starikov, K V; Deutsch, C

    2005-02-01

    The stopping mechanisms of relativistic electron beams in superdense and partially degenerate electron fluid targets are investigated in the framework of the fast ignitor concept for inertial confinement fusion. In order to comply with specific demands in this area, we focus attention on the target partial degeneracy parameter theta= T(e) / T(f) , in terms of the thermal to Fermi temperature ratio. The target electron fluid is thus modeled very accurately with a random phase approximation dielectric function. The stopping results are shown to be very weakly theta dependent. However, a quantum target description is needed to recover their correct increasing trend with increasing projectile energy. The ranges and effective penetration depths in precompressed thermonuclear fuels are shown to be nearly a factor of 2 shorter than earlier classical estimates in the same conditions. The overall conclusions pertaining to the feasibility of fast ignition thus remain unchanged. PMID:15783429

  10. Interaction of superintense laser pulses with relativistic ions.

    PubMed

    Chirilă, C C; Joachain, C J; Kylstra, N J; Potvliege, R M

    2004-12-10

    At high intensities, three-step recollision processes driven by low frequency laser pulses, such as high-order harmonic generation and high-order above-threshold ionization, are normally severely suppressed by the magnetic-field component of the laser field. It is shown that this suppression is not severe, even for ponderomotive energies well above 10 keV, for multicharged ions moving at a sufficiently high relativistic velocity against a counterpropagating infrared laser pulse. Numerical results are presented for high-order harmonic emission by a single Ne9+ ion moving with a Lorentz factor gamma=15 against a Nd:glass laser beam. The calculations are done within a Coulomb-corrected nondipole strong field approximation. The approximation is tested by comparing with accurate results. PMID:15697809

  11. Interaction of Superintense Laser Pulses with Relativistic Ions

    NASA Astrophysics Data System (ADS)

    Chirilă, C. C.; Joachain, C. J.; Kylstra, N. J.; Potvliege, R. M.

    2004-12-01

    At high intensities, three-step recollision processes driven by low frequency laser pulses, such as high-order harmonic generation and high-order above-threshold ionization, are normally severely suppressed by the magnetic-field component of the laser field. It is shown that this suppression is not severe, even for ponderomotive energies well above 10keV, for multicharged ions moving at a sufficiently high relativistic velocity against a counterpropagating infrared laser pulse. Numerical results are presented for high-order harmonic emission by a single Ne9+ ion moving with a Lorentz factor γ=15 against a Nd:glass laser beam. The calculations are done within a Coulomb-corrected nondipole strong field approximation. The approximation is tested by comparing with accurate results.

  12. Towards the island of stability with relativistic energy density functionals

    SciTech Connect

    Prassa, V.; Niksic, T.; Lalazissis, G. A.; Vretenar, D.

    2012-10-20

    Relativistic energy density functionals (REDF) provide a complete and accurate, global description of nuclear structure phenomena. Modern semi-empirical functionals, adjusted to the nuclear matter equation of state and to empirical masses of deformed nuclei, are applied to studies of shapes of superheavy nuclei. The theoretical framework is tested in a comparison to empirical masses, quadrupole deformations, and energy barriers of actinide nuclei. The model is used in a self-consistent mean-field calculation of spherical, axial and triaxial shapes of superheavy nuclei, alpha-decay energies and lifetimes. The effect of explicit treatment of collective correlations is analyzed in calculations that consistently use a collective Hamiltonian model based on REDFs.

  13. Numerical split-shift potential method for relativistic quantum systems with radial symmetry

    NASA Astrophysics Data System (ADS)

    Lv, Q. Z.; Norris, S.; Su, Q.; Grobe, R.

    2016-03-01

    We show how the spectrum of a radially symmetric Dirac Hamiltonian can be computed rather accurately on a spatial grid using a split-shift potential method. This method is sufficiently accurate such that the fine structure splittings of hydrogen-like relativistic ions with nuclear charge Z can be reproduced for a relatively small number of spatial radial grid points. We use this analytically known spectrum to examine the error scaling of this method. The method is then applied to examine the impact of a spatial confinement on the fine structure splittings and the bound states for hydrogen.

  14. Relativistic Particle-In-Cell Simulations of Particle Accleration in Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Hardee, P.; Mizuno, Y.; Medvedev, M.; Hartmann, D. H.; Fishman, J. F.

    2008-01-01

    Highly accelerated particles are observed in astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), microquasars, and Gamma-Ray Bursts (GRBs). Particle-In-Cell (PIC) simulations of relativistic electron-ion and electron-positron jets injected into a stationary medium show that efficient acceleration occurs downstream in the jet. In collisionless relativistic shocks particle acceleration is due to plasma waves and their associated instabilities, e.g., the Buneman instability, other two-stream instabilities, and the Weibel (filamentation) instability. Simulations show that the Weibel instability is responsible for generating and amplifying highly non-uniform, small-scale magnetic fields. The instability depends on strength and direction of the magnetic field. Particles in relativistic jets may be accelerated in a complicated dynamics of relativistic jets with magnetic field. We present results of our recent PIC simulations.

  15. Accurate ab Initio Spin Densities

    PubMed Central

    2012-01-01

    We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as a basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys.2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CASCI-type wave function provides insight into chemically interesting features of the molecule under study such as the distribution of α and β electrons in terms of Slater determinants, CI coefficients, and natural orbitals. The methodology is applied to an iron nitrosyl complex which we have identified as a challenging system for standard approaches [J. Chem. Theory Comput.2011, 7, 2740]. PMID:22707921

  16. Relativistic generation of vortex and magnetic field

    SciTech Connect

    Mahajan, S. M.; Yoshida, Z.

    2011-05-15

    The implications of the recently demonstrated relativistic mechanism for generating generalized vorticity in purely ideal dynamics [Mahajan and Yoshida, Phys. Rev. Lett. 105, 095005 (2010)] are worked out. The said mechanism has its origin in the space-time distortion caused by the demands of special relativity; these distortions break the topological constraint (conservation of generalized helicity) forbidding the emergence of magnetic field (a generalized vorticity) in an ideal nonrelativistic dynamics. After delineating the steps in the ''evolution'' of vortex dynamics, as the physical system goes from a nonrelativistic to a relativistically fast and hot plasma, a simple theory is developed to disentangle the two distinct components comprising the generalized vorticity--the magnetic field and the thermal-kinetic vorticity. The ''strength'' of the new universal mechanism is, then, estimated for a few representative cases; in particular, the level of seed fields, created in the cosmic setting of the early hot universe filled with relativistic particle-antiparticle pairs (up to the end of the electron-positron era), are computed. Possible applications of the mechanism in intense laser produced plasmas are also explored. It is suggested that highly relativistic laser plasma could provide a laboratory for testing the essence of the relativistic drive.

  17. Relativistic mixtures of charged and uncharged particles

    SciTech Connect

    Kremer, Gilberto M.

    2014-01-14

    Mixtures of relativistic gases within the framework of Boltzmann equation are analyzed. Three systems are considered. The first one refers to a mixture of uncharged particles by using Grad’s moment method, where the relativistic mixture is characterized by the moments of the distribution functions: particle four-flows, energy-momentum tensors, and third-order moment tensors. In the second Fick’s law for a mixture of relativistic gases of non-disparate rest masses in a Schwarzschild metric are derived from an extension of Marle and McCormack model equations applied to a relativistic truncated Grad’s distribution function, where it is shown the dependence of the diffusion coefficient on the gravitational potential. The third one consists in the derivation of the relativistic laws of Ohm and Fourier for a binary mixtures of electrons with protons and electrons with photons subjected to external electromagnetic fields and in presence of gravitational fields by using the Anderson and Witting model of the Boltzmann equation.

  18. Imbalanced relativistic force-free magnetohydrodynamic turbulence

    SciTech Connect

    Cho, Jungyeon; Lazarian, A.

    2014-01-01

    When magnetic energy density is much larger than that of matter, as in pulsar/black hole magnetospheres, the medium becomes force-free and we need relativity to describe it. As in non-relativistic magnetohydrodynamics (MHD), Alfvénic MHD turbulence in the relativistic limit can be described by interactions of counter-traveling wave packets. In this paper, we numerically study strong imbalanced MHD turbulence in such environments. Here, imbalanced turbulence means the waves traveling in one direction (dominant waves) have higher amplitudes than the opposite-traveling waves (sub-dominant waves). We find that (1) spectrum of the dominant waves is steeper than that of sub-dominant waves, (2) the anisotropy of the dominant waves is weaker than that of sub-dominant waves, and (3) the dependence of the ratio of magnetic energy densities of dominant and sub-dominant waves on the ratio of energy injection rates is steeper than quadratic (i.e., b{sub +}{sup 2}/b{sub −}{sup 2}∝(ϵ{sub +}/ϵ{sub −}){sup n} with n > 2). These results are consistent with those obtained for imbalanced non-relativistic Alfvénic turbulence. This corresponds well to the earlier reported similarity of the relativistic and non-relativistic balanced magnetic turbulence.

  19. UNIVERSALITY AND INTERMITTENCY IN RELATIVISTIC TURBULENT FLOWS OF A HOT PLASMA

    SciTech Connect

    Radice, David; Rezzolla, Luciano

    2013-03-20

    With the aim of determining the statistical properties of relativistic turbulence and unveiling novel and non-classical features, we present the results of direct numerical simulations of driven turbulence in an ultrarelativistic hot plasma using high-order numerical schemes. We study the statistical properties of flows with average Mach numbers ranging from {approx}0.4 to {approx}1.7 and with average Lorentz factors up to {approx}1.7. We find that flow quantities, such as the energy density or the local Lorentz factor, show large spatial variance even in the subsonic case as compressibility is enhanced by relativistic effects. The velocity field is highly intermittent, but its power spectrum is found to be in good agreement with the predictions of the classical theory of Kolmogorov. Overall, our results indicate that relativistic effects are able to significantly enhance the intermittency of the flow and affect the high-order statistics of the velocity field, while leaving unchanged the low-order statistics, which instead appear to be universal and in good agreement with the classical Kolmogorov theory. To the best of our knowledge, these are the most accurate simulations of driven relativistic turbulence to date.

  20. The pure rotational spectrum of ruthenium monocarbide, RuC, and relativistic ab initio predictions

    SciTech Connect

    Wang, Fang; Steimle, Timothy C.; Adam, Allan G.; Cheng, Lan; Stanton, John F.

    2013-11-07

    The J = 1 ← J = 0 and J = 2 ← J = 1 rotational transitions of ruthenium monocarbide, RuC, have been recorded using the separated field pump/probe microwave optical double resonance technique and analyzed to determine the fine and hyperfine parameters for the X{sup 1}Σ{sup +} state. The {sup 101}Ru(I = 5/2) electric quadrupole parameter, eq{sub 0}Q, and nuclear spin-rotation interaction parameter, C{sub I}{sup eff}, were determined to be 433.19(8) MHz and −0.049(6) MHz, respectively. The equilibrium bond distance, r{sub e}, was determined to be 1.605485(2) Å. Hartree-Fock and coupled-cluster calculations were carried out for the properties of the X{sup 1}Σ{sup +} state. Electron-correlation effects are pronounced for all properties studied. It is shown that (a) the moderate scalar-relativistic contribution to eq{sub 0}Q is entirely due to the coupling between scalar-relativistic and electron-correlation effects, (b) the spin-free exact two-component theory in its one-electron variant offers a reliable and efficient treatment of scalar-relativistic effects, and (c) non-relativistic theory performs quite well for the prediction of C{sub I}{sup elec}, provided that electron correlation is treated accurately.

  1. Radiation-Dominated Relativistic Current Sheets

    SciTech Connect

    Jaroschek, C. H.; Hoshino, M.

    2009-08-14

    Relativistic current sheets (RCSs) feature plasma instabilities considered as the potential key to magnetic energy dissipation in Poynting-flux-dominated plasma flows. Kinetic plasma simulations show that the physical nature of RCS evolution changes in the presence of radiation losses: In the ultrarelativistic regime (i.e., magnetization parameter sigma=10{sup 4} defined as the ratio of magnetic to plasma rest frame energy density), the combined effect of nonlinear RCS dynamics and synchrotron emission introduces a temperature anisotropy triggering the growth of the relativistic tearing mode. In contrast to previous studies of the RCS with sigmaapprox1, the relativistic tearing mode then prevails over the drift kink mode. The ultrarelativistic RCS shows a typical life cycle from radiation-induced collapse towards a radiation-quiescent phase with topology analogous to that introduced by Sweet and Parker.

  2. Relativistic electron acceleration by oblique whistler waves

    SciTech Connect

    Yoon, Peter H.; Pandey, Vinay S.; Lee, Dong-Hun

    2013-11-15

    Test-particle simulations of electrons interacting with finite-amplitude, obliquely propagating whistler waves are carried out in order to investigate the acceleration of relativistic electrons by these waves. According to the present findings, an efficient acceleration of relativistic electrons requires a narrow range of oblique propagation angles, close to the whistler resonance cone angle, when the wave amplitude is held constant at relatively low value. For a constant wave propagation angle, it is found that a range of oblique whistler wave amplitudes permits the acceleration of relativistic electrons to O(MeV) energies. An initial distribution of test electrons is shown to form a power-law distribution when plotted in energy space. It is also found that the acceleration is largely uniform in electron pitch-angle space.

  3. Relativistic Entanglement From Maxwell's Classical Equations

    NASA Astrophysics Data System (ADS)

    Carroll, John E.; Quarterman, Adrian H.

    2013-09-01

    With the help of light cone coordinates and light cone field representations of Maxwell's classical equations, quantum polarization entanglement is explained using the relativistic results of a companion paper that shows how conventional or reference waves can have an adjoint wave, travelling in phase with the reference wave, but in a proper relativistic frame that travels in the opposing direction to the proper frame of the reference wave. This subsequently allows waves, travelling in opposite directions, to have the same proper frame and consequently such waves can be regarded as relativistically local. The light cone coordinates offer a classical form of a quantum wave function and demonstrate a classical equivalent of a mixed quantum state.

  4. Relativistic spin operators in various electromagnetic environments

    NASA Astrophysics Data System (ADS)

    Bauke, Heiko; Ahrens, Sven; Keitel, Christoph H.; Grobe, Rainer

    2014-05-01

    Different operators have been suggested in the literature to describe the electron's spin degree of freedom within the relativistic Dirac theory. We compare concrete predictions of the various proposed relativistic spin operators in different physical situations. In particular, we investigate the so-called Pauli, Foldy-Wouthuysen, Czachor, Frenkel, Chakrabarti, Pryce, and Fradkin-Good spin operators. We demonstrate that when a quantum system interacts with electromagnetic potentials the various spin operators predict different expectation values. This is explicitly illustrated for the scattering dynamics at a potential step and in a standing laser field and also for energy eigenstates of hydrogenic ions. Therefore, one may distinguish between the proposed relativistic spin operators experimentally.

  5. Resistive Magnetohydrodynamic Simulations of Relativistic Magnetic Reconnection

    NASA Technical Reports Server (NTRS)

    Zenitani, Seiji; Hesse, Michael; Klimas, Alex

    2010-01-01

    Resistive relativistic magnetohydrodynamic (RRMHD) simulations are applied to investigate the system evolution of relativistic magnetic reconnection. A time-split Harten-Lan-van Leer method is employed. Under a localized resistivity, the system exhibits a fast reconnection jet with an Alfv enic Lorentz factor inside a narrow Petschek-type exhaust. Various shock structures are resolved in and around the plasmoid such as the post-plasmoid vertical shocks and the "diamond-chain" structure due to multiple shock reflections. Under a uniform resistivity, Sweet-Parker-type reconnection slowly evolves. Under a current-dependent resistivity, plasmoids are repeatedly formed in an elongated current sheet. It is concluded that the resistivity model is of critical importance for RRMHD modeling of relativistic magnetic reconnection.

  6. New developments in relativistic dissipative fluid dynamics

    NASA Astrophysics Data System (ADS)

    Muronga, Azwinndini

    2010-09-01

    The recent notion of the perfect fluid created at the relativistic heavy ion collider (RHIC) has been embraced by many experimentalists and theorists alike. However, much of the evidence to this notion has been based on the success of describing some experimental observables by non-viscous hydrodynamics or by small shear viscosity to entropy density ratio. Developments on viscous hydrodynamics evolved from (0+1) dimensions (Bjorken scaling solution) over (1+1) dimensions (Bjorken + transverse flow) to (2+1) dimensions (elliptic flow) and currently (3+1) dimensions. There still exist some formal issues concerning the allowed form of the relativistic viscous hydrodynamic equations and what effects the new additional or higher order terms will have on the spacetime evolution and the experimental observables. Starting with a brief introduction of the basics of relativsitic fluid dynamics, I will discuss our current knowledge of relativistic theory of fluid dynamics in the presence of dissipative fluxes.

  7. Corrugation of Relativistic Magnetized Shock Waves

    NASA Astrophysics Data System (ADS)

    Lemoine, Martin; Ramos, Oscar; Gremillet, Laurent

    2016-08-01

    As a shock front interacts with turbulence it develops corrugation, which induces outgoing wave modes in the downstream plasma. For a fast shock wave, the incoming wave modes can either be fast magnetosonic waves originating downstream, outrunning the shock, or eigenmodes of the upstream plasma drifting through the shock. Using linear perturbation theory in relativistic MHD, this paper provides a general analysis of the corrugation of relativistic magnetized fast shock waves resulting from their interaction with small amplitude disturbances. Transfer functions characterizing the linear response for each of the outgoing modes are calculated as a function of the magnetization of the upstream medium and as a function of the nature of the incoming wave. Interestingly, if the latter is an eigenmode of the upstream plasma, we find that there exists a resonance at which the (linear) response of the shock becomes large or even diverges. This result may have profound consequences on the phenomenology of astrophysical relativistic magnetized shock waves.

  8. Relativistic spin precession in the double pulsar.

    PubMed

    Breton, Rene P; Kaspi, Victoria M; Kramer, Michael; McLaughlin, Maura A; Lyutikov, Maxim; Ransom, Scott M; Stairs, Ingrid H; Ferdman, Robert D; Camilo, Fernando; Possenti, Andrea

    2008-07-01

    The double pulsar PSR J0737-3039A/B consists of two neutron stars in a highly relativistic orbit that displays a roughly 30-second eclipse when pulsar A passes behind pulsar B. Describing this eclipse of pulsar A as due to absorption occurring in the magnetosphere of pulsar B, we successfully used a simple geometric model to characterize the observed changing eclipse morphology and to measure the relativistic precession of pulsar B's spin axis around the total orbital angular momentum. This provides a test of general relativity and alternative theories of gravity in the strong-field regime. Our measured relativistic spin precession rate of 4.77 degrees (-0 degrees .65)(+0 degrees .66) per year (68% confidence level) is consistent with that predicted by general relativity within an uncertainty of 13%. PMID:18599782

  9. Relativistic neutrons in active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Sikora, Marek; Begelman, Mitchell C.; Rudak, Bronislaw

    1989-01-01

    The acceleration of protons to relativistic energies in active galactic nuclei leads to the creation of relativistic neutrons which escape from the central engine. The neutrons decay at distances of up to 1-100 pc, depositing their energies and momenta in situ. Energy deposition by decaying neutrons may inhibit spherical accretion and drive a wind, which could be responsible for the velocity fields in emission-line regions and the outflow of broad absorption line systems. Enhanced pressure in the neutron decay region may also help to confine emission line clouds. A fraction of the relativistic proton energy is radiated in gamma-rays with energies which may be as large as about 100,000 GeV.

  10. Viscous photons in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Dion, Maxime; Paquet, Jean-François; Schenke, Björn; Young, Clint; Jeon, Sangyong; Gale, Charles

    2011-12-01

    Theoretical studies of the production of real thermal photons in relativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are performed. The space-time evolution of the colliding system is modelled using music, a 3+1D relativistic hydrodynamic simulation, using both its ideal and viscous versions. The inclusive spectrum and its azimuthal angular anisotropy are studied separately, and the relative contributions of the different photon sources are highlighted. It is shown that the photon v2 coefficient is especially sensitive to the details of the microscopic dynamics like the equation of state, the ratio of shear viscosity over entropy density, η/s, and to the morphology of the initial state.

  11. Relativistic dynamics, Green function and pseudodifferential operators

    NASA Astrophysics Data System (ADS)

    Cirilo-Lombardo, Diego Julio

    2016-06-01

    The central role played by pseudodifferential operators in relativistic dynamics is known very well. In this work, operators like the Schrodinger one (e.g., square root) are treated from the point of view of the non-local pseudodifferential Green functions. Starting from the explicit construction of the Green (semigroup) theoretical kernel, a theorem linking the integrability conditions and their dependence on the spacetime dimensions is given. Relativistic wave equations with arbitrary spin and the causality problem are discussed with the algebraic interpretation of the radical operator and their relation with coherent and squeezed states. Also we perform by means of pure theoretical procedures (based in physical concepts and symmetry) the relativistic position operator which satisfies the conditions of integrability: it is a non-local, Lorentz invariant and does not have the same problems as the "local"position operator proposed by Newton and Wigner. Physical examples, as zitterbewegung and rogue waves, are presented and deeply analyzed in this theoretical framework.

  12. Relativistic transport theory for cosmic-rays

    NASA Technical Reports Server (NTRS)

    Webb, G. M.

    1985-01-01

    Various aspects of the transport of cosmic-rays in a relativistically moving magnetized plasma supporting a spectrum of hydromagnetic waves that scatter the cosmic-rays are presented. A local Lorentz frame moving with the waves or turbulence scattering the cosmic-rays is used to specify the individual particle momentum. The comoving frame is in general a noninertial frame in which the observer's volume element is expanding and shearing, geometric energy change terms appear in the cosmic-ray transport equation which consist of the relativistic generalization of the adiabatic deceleration term and a further term involving the acceleration vector of the scatterers. A relativistic version of the pitch angle evolution equation, including the effects of adiabatic focussing, pitch angle scattering, and energy changes is presented.

  13. Relativistic runaway electrons above thunderstorms

    NASA Astrophysics Data System (ADS)

    Lehtinen, Nikolai G.

    A three-dimensional Monte Carlo model of the uniform relativistic runaway electron breakdown in air in the presence of static electric and magnetic fields is developed and used to calculate electron distribution functions, avalanche rates and the direction and velocity of avalanche propagation. The Monte Carlo simulation results are used in a fluid model of a runaway electron beam in the middle atmosphere accelerated by quasi-electrostatic fields following a positive lightning stroke. We consider the case of lightning discharges which drain positive charge from remote regions of a laterally extensive (>100 km) thundercloud in a thunderstorm located at ~45° geomagnetic latitude, using a translationally invariant two-dimensional model. We also consider a cylindrically symmetric model with a vertical axis of symmetry, constrained to a vertical geomagnetic field. In both models, the optical emission intensities produced by the runaway electrons are found to be negligible compared to the emissions produced by thermal electrons heated in the conventional type of breakdown. The calculated γ-ray flux is of the same order as the terrestrial γ-ray flashes observed by the BATSE detector on the Compton Gamma Ray Observatory. The energetic electrons leaving the atmosphere undergo intense interactions with the background magnetospheric plasma, leading to rapid growth of Langmuir waves with rate found based on the energy electron distribution and intense scattering of the electrons. In the nonlinear stage, beam electrons acquire an isotropic thermal distribution with a typical energy of ~1 MeV within one interhemispheric traverse along the Earth's magnetic field lines. While the electrons within the loss cone precipitate out, most of the electrons get trapped and form detectable energetic electron curtains surrounding the Earth. Electrons with pitch angles below the loss cone encounter the Earth's atmosphere at the conjugate point, are scattered and produce light, ionization

  14. Relativistic heavy quark spectrum on anisotropic lattices

    NASA Astrophysics Data System (ADS)

    Liao, Xiaodong

    We report a fully relativistic quenched calculation of the heavy quark spectrum, including both charmonium and bottomonium, using anisotropic lattice QCD. We demonstrate that a fully relativistic treatment of a heavy quark system is well-suited to address the large systematic errors in non-relativistic calculations. In addition, the anisotropic lattice formulation is a very efficient framework for calculations requiring high temporal resolutions. A detailed excited charmonium spectrum is obtained, including both the exotic hybrids (with JPC = 1-+ , 0+-, 2+-) and orbitally excited mesons (with orbital angular momentum up to 3). Using three different lattice spacings (0.197, 0.131, and 0.092 fm), we perform a continuum extrapolation of the spectrum. The lowest lying exotic hybrid 1-+ lies at 4.428(41) GeV, slightly above the D**D (S + P wave) threshold of 4.287 GeV. Another two exotic hybrids 0+- and 2 +- are determined to be 4.70(17) GeV and 4.895(88) GeV, respectively. Our finite volume analysis confirms that our lattices are large enough to accommodate all the excited states reported here. We did the first relativistic calculation of the quenched bottomonium spectrum from anisotropic lattices. Using a very fine discretization in the temporal direction we were able to go beyond the non-relativistic approximation and perform a continuum extrapolation of our results from five different lattice spacings (0.04--0.17 fm) and two anisotropies (4 and 5). We investigate several systematic errors within the quenched approximation and compare our results with those from non-relativistic simulations.

  15. The relativistic equations of stellar structure and evolution

    NASA Technical Reports Server (NTRS)

    Thorne, K. S.

    1977-01-01

    The general-relativistic equations of stellar structure and evolution are reformulated in a notation which makes easy contact with Newtonian theory. Also, a general-relativistic version of the mixing-length formalism for convection is presented.

  16. Properties of compressible elastica from relativistic analogy.

    PubMed

    Oshri, Oz; Diamant, Haim

    2016-01-21

    Kirchhoff's kinetic analogy relates the deformation of an incompressible elastic rod to the classical dynamics of rigid body rotation. We extend the analogy to compressible filaments and find that the extension is similar to the introduction of relativistic effects into the dynamical system. The extended analogy reveals a surprising symmetry in the deformations of compressible elastica. In addition, we use known results for the buckling of compressible elastica to derive the explicit solution for the motion of a relativistic nonlinear pendulum. We discuss cases where the extended Kirchhoff analogy may be useful for the study of other soft matter systems. PMID:26563905

  17. Relativistic helix traveling wave tube amplifiers

    SciTech Connect

    Freund, H.P.; Vanderplaats, N.R.; Kodis, M.A. )

    1992-07-01

    A relativistic field theory of a helix traveling wave tube (TWT) is described for the case in which a thin annular beam propagates through a sheath helix enclosed within a loss-free wall. The theory is applied to the study of a TWT with an intense relativistic electron beam. The analysis implicitly includes beam space-charge effects and is valid for arbitrary azimuthal mode number, and the coupled-wave Pierce theory is recovered in the [ital near]-[ital resonant] limit. The results indicate that impressive gains and efficiencies are possible in this regime. In addition, the interaction is relatively insensitive to the effects of a beam energy spread.

  18. Newtonian hydrodynamics with general relativistic pressure

    SciTech Connect

    Hwang, Jai-chan; Noh, Hyerim E-mail: hr@kasi.re.kr

    2013-10-01

    We present the general relativistic pressure correction terms in Newtonian hydrodynamic equations to the nonlinear order: these are equations (1.1)–(1.3). The derivation is made in the zero-shear gauge based on the fully nonlinear formulation of cosmological perturbation in Einstein's gravity. The correction terms differ from many of the previously suggested forms in the literature based on hand-waving manners. We confirm our results by comparing with (i) the nonlinear perturbation theory, (ii) the first order post-Newtonian approximation, and (iii) the special relativistic limit, and by checking (iv) the consistency with full Einstein's equation.

  19. Relativistic Plasmas in Low Density Environments

    SciTech Connect

    Rudnick, Lawrence

    2009-12-18

    We have been developing techniques over the last several years to identify and study relativistic plasmas in low density environments. These relativistic plasmas may be the best or only available indicators of diffuse baryons in portions of the Warm-Hot Intergalactic Medium outside of rich galaxy clusters. Studying such faint radio synchrotron sources requires removal of confusion from both background radio galaxies and the foreground Milky Way. In these proceedings, we briefly summarize the techniques we are developing and some of our initial results. Our discoveries likely represent the ''tip of the iceberg'' to be exploited by the nascent generation of radio telescopes.

  20. Can Bohmian mechanics be made relativistic?

    PubMed

    Dürr, Detlef; Goldstein, Sheldon; Norsen, Travis; Struyve, Ward; Zanghì, Nino

    2014-02-01

    In relativistic space-time, Bohmian theories can be formulated by introducing a privileged foliation of space-time. The introduction of such a foliation-as extra absolute space-time structure-would seem to imply a clear violation of Lorentz invariance, and thus a conflict with fundamental relativity. Here, we consider the possibility that, instead of positing it as extra structure, the required foliation could be covariantly determined by the wave function. We argue that this allows for the formulation of Bohmian theories that seem to qualify as fundamentally Lorentz invariant. We conclude with some discussion of whether or not they might also qualify as fundamentally relativistic. PMID:24511259

  1. Generalized magnetofluid connections in relativistic magnetohydrodynamics.

    PubMed

    Asenjo, Felipe A; Comisso, Luca

    2015-03-20

    The concept of magnetic connections is extended to nonideal relativistic magnetohydrodynamical plasmas. Adopting a general set of equations for relativistic magnetohydrodynamics including thermal-inertial, thermal electromotive, Hall, and current-inertia effects, we derive a new covariant connection equation showing the existence of generalized magnetofluid connections that are preserved during the dissipationless plasma dynamics. These connections are intimately linked to a general antisymmetric tensor that unifies the electromagnetic and fluid fields, allowing the extension of the magnetic connection notion to a much broader concept. PMID:25839284

  2. Nonaxisymmetric oscillations of differentially rotating relativistic stars

    SciTech Connect

    Passamonti, Andrea; Stavridis, Adamantios; Kokkotas, Kostas D.

    2008-01-15

    Nonaxisymmetric oscillations of differentially rotating stars are studied using both slow rotation and Cowling approximation. The equilibrium stellar models are relativistic polytropes where differential rotation is described by the relativistic j-constant rotation law. The oscillation spectrum is studied versus three main parameters: the stellar compactness M/R, the degree of differential rotation A, and the number of maximum couplings l{sub max}. It is shown that the rotational splitting of the nonaxisymmetric modes are strongly enhanced by increasing the compactness of the star and the degree of differential rotation. Finally, we investigate the relation between the fundamental quadrupole mode and the corotation band of differentially rotating stars.

  3. Structure of hypernuclei in relativistic approaches

    NASA Astrophysics Data System (ADS)

    Hagino, Kouichi; Yao, Jiangming

    We review the relativistic mean-field approaches to hypernuclear physics. This includes Lambda hypernuclei, anti-Lambda hypernuclei, and multistrangeness hypernuclei. We particularly focus on the properties of both ground state and collective excitations, hyperon binding energies, spinorbit splittings, magnetic moments, a stabilization of drip-line nuclei, and the hyperon impurity effect on nuclear collectivity. We also discuss briefly the influence of hyperons on neutron stars. We conclude that the relativistic mean-field approaches have achieved a great success in the studies of hypernuclear physics.

  4. Relativistic klystron research for high gradient accelerators

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Lavine, T.L.; Lee, T.G.

    1988-06-01

    Relativistic klystrons are being developed as a power source for high gradient accelerator applications which include large linear electron--positron colliders, compact accelerators, and FEL sources. We have attained 200MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here on the design of our first klystrons, the results of our experiments so far, and some of our plans for the near future. 5 refs., 7 figs.

  5. Recent progress in relativistic klystron research

    SciTech Connect

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Hoag, H.A.; Koontz, R.F.; Lavine, T.L.; Loew, G.A.; Miller, R.H.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W.; Aalberts, D.P.; Boyd, J.K.; Houck, T.; Ryne, R.D.; Westenskow, G.A.; Yu, S.S.; Hopkins, D.B.; Sessler, A.M.; Haimson, J.; Mecklenburg, B.; Lawrence Livermore National Lab., CA (US

    1989-08-01

    Experimental work is now under way by collaborators at LLNL, SLAC, and LBL to investigate relativistic klystrons as a possible rf power source for future high-gradient accelerators. We have learned how to overcome our previously reported problem of high-power rf pulse shortening and have achieved peak rf power levels of 290 MW. We have used the rf from a relativistic klystron to power a short, 11.4-GHz high-gradient accelerator. The measured momentum spectrum of the accelerated electron beam corresponds to an accelerating gradient of 84 MV/m. 5 refs., 7 figs.

  6. Towards universal quantum computation through relativistic motion

    PubMed Central

    Bruschi, David Edward; Sabín, Carlos; Kok, Pieter; Johansson, Göran; Delsing, Per; Fuentes, Ivette

    2016-01-01

    We show how to use relativistic motion to generate continuous variable Gaussian cluster states within cavity modes. Our results can be demonstrated experimentally using superconducting circuits where tuneable boundary conditions correspond to mirrors moving with velocities close to the speed of light. In particular, we propose the generation of a quadripartite square cluster state as a first example that can be readily implemented in the laboratory. Since cluster states are universal resources for universal one-way quantum computation, our results pave the way for relativistic quantum computation schemes. PMID:26860584

  7. Multiscale structures in relativistic pair plasmas

    SciTech Connect

    Iqbal, M.; Berezhiani, V. I.; Yoshida, Z.

    2008-03-15

    The steady-state solution of a pair plasma with relativistic thermal velocity of the constituent particles (electrons and positrons) is investigated. The relaxed state can be written as a superposition of three Beltrami fields. Generally, the associated scale parameters could be a complex conjugate pair and a real one. It is shown that at higher thermal energies, all the scale parameters become real. It is also observed that one component gets a large scale (system size) while the other two components appear with small scale of the order of the skin depth at relativistic temperature.

  8. Relativistic plasma shutter for ultraintense laser pulses

    PubMed Central

    Reed, Stephen A.; Matsuoka, Takeshi; Bulanov, Stepan; Tampo, Motonobu; Chvykov, Vladimir; Kalintchenko, Galina; Rousseau, Pascal; Yanovsky, Victor; Kodama, Ryousuke; Litzenberg, Dale W.; Krushelnick, Karl; Maksimchuk, Anatoly

    2009-01-01

    A relativistic plasma shutter technique is proposed and tested to remove the sub-100 ps pedestal of a high-intensity laser pulse. The shutter is an ultrathin foil placed before the target of interest. As the leading edge of the laser ionizes the shutter material it will expand into a relativistically underdense plasma allowing for the peak pulse to propagate through while rejecting the low intensity pedestal. An increase in the laser temporal contrast is demonstrated by measuring characteristic signatures in the accelerated proton spectra and directionality from the interaction of 30 TW pulses with ultrathin foils along with supporting hydrodynamic and particle-in-cell simulations. PMID:19654882

  9. Alfven solitary waves in nonrelativistic, relativistic, and ultra-relativistic degenerate quantum plasma

    SciTech Connect

    Rehman, M. A.; Qureshi, M. N. S.; Shah, H. A.; Masood, W.

    2015-10-15

    Nonlinear circularly polarized Alfvén waves are studied in magnetized nonrelativistic, relativistic, and ultrarelativistic degenerate Fermi plasmas. Using the quantum hydrodynamic model, Zakharov equations are derived and the Sagdeev potential approach is used to investigate the properties of the electromagnetic solitary structures. It is seen that the amplitude increases with the increase of electron density in the relativistic and ultrarelativistic cases but decreases in the nonrelativistic case. Both right and left handed waves are considered, and it is seen that supersonic, subsonic, and super- and sub-Alfvénic solitary structures are obtained for different polarizations and under different relativistic regimes.

  10. Relativistic and non-relativistic analysis of whistler-mode waves in a hot anisotropic plasma

    NASA Astrophysics Data System (ADS)

    Sazhin, S. S.; Sumner, A. E.; Temme, N. M.

    1992-02-01

    The dispersion equation for parallel whistler-mode propagation in a hot anisotropic plasma is analysed numerically in both weakly relativistic and nonrelativistic approximations under the assumption that wave growth or damping does not influence the wave refractive index. The results of this analysis are compared with the results of an asymptotic analysis of the same equation, and the range of applicability of the latter results is specified. It is pointed out that relativistic effects lead to a decrease in the range of frequencies for which instability occurs. For a moderately anisotropic plasma (T/T = 2) relativistic effects lead to an increase in the maximum value of the increment of instability.

  11. Non-relativistic fields from arbitrary contracting backgrounds

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric; Rosseel, Jan; Zojer, Thomas

    2016-09-01

    We discuss a non-relativistic contraction of massive and massless field theories minimally coupled to gravity. Using the non-relativistic limiting procedure introduced in our previous work, we (re-)derive non-relativistic field theories of massive and massless spins 0 to 3/2 coupled to torsionless Newton–Cartan backgrounds. We elucidate the relativistic origin of the Newton–Cartan central charge gauge field {m}μ and explain its relation to particle number conservation.

  12. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  13. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  14. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  15. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  16. 38 CFR 4.46 - Accurate measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Accurate measurement. 4... RATING DISABILITIES Disability Ratings The Musculoskeletal System § 4.46 Accurate measurement. Accurate measurement of the length of stumps, excursion of joints, dimensions and location of scars with respect...

  17. Relativistic electron scattering by magnetosonic waves: Effects of discrete wave emission and high wave amplitudes

    SciTech Connect

    Artemyev, A. V.; Mourenas, D.; Krasnoselskikh, V. V.

    2015-06-15

    In this paper, we study relativistic electron scattering by fast magnetosonic waves. We compare results of test particle simulations and the quasi-linear theory for different spectra of waves to investigate how a fine structure of the wave emission can influence electron resonant scattering. We show that for a realistically wide distribution of wave normal angles θ (i.e., when the dispersion δθ≥0.5{sup °}), relativistic electron scattering is similar for a wide wave spectrum and for a spectrum consisting in well-separated ion cyclotron harmonics. Comparisons of test particle simulations with quasi-linear theory show that for δθ>0.5{sup °}, the quasi-linear approximation describes resonant scattering correctly for a large enough plasma frequency. For a very narrow θ distribution (when δθ∼0.05{sup °}), however, the effect of a fine structure in the wave spectrum becomes important. In this case, quasi-linear theory clearly fails in describing accurately electron scattering by fast magnetosonic waves. We also study the effect of high wave amplitudes on relativistic electron scattering. For typical conditions in the earth's radiation belts, the quasi-linear approximation cannot accurately describe electron scattering for waves with averaged amplitudes >300 pT. We discuss various applications of the obtained results for modeling electron dynamics in the radiation belts and in the Earth's magnetotail.

  18. High order numerical simulations of the Richtmyer- Meshkov instability in a relativistic fluid

    NASA Astrophysics Data System (ADS)

    Zanotti, O.; Dumbser, M.

    2015-07-01

    We study the Richtmyer-Meshkov (RM) instability of a relativistic perfect fluid by means of high order numerical simulations with adaptive mesh refinement (AMR). The numerical scheme combines a finite volume reconstruction in space, a local space-time discontinuous Galerkin predictor method, a high order one-step time update scheme, and a "cell-by-cell" space-time AMR strategy with time-accurate local time stepping. In this way, third order accurate (both in space and in time) numerical simulations of the RM instability are performed, spanning a wide parameter space. We present results both for the case in which a light fluid penetrates into a higher density one (Atwood number A > 0) and for the case in which a heavy fluid penetrates into a lower density one (Atwood number A < 0). We find that for large Lorentz factors γs of the incident shock wave, the relativistic RM instability is substantially weakened and ultimately suppressed. More specifically, the growth rate of the RM instability in the linear phase has a local maximum which occurs at a critical value of γs ≈ [1.2, 2]. Moreover, we have also revealed a genuinely relativistic effect, absent in Newtonian hydrodynamics, which arises in three dimensional configurations with a non-zero velocity component tangent to the incident shock front. In particular, in A > 0 models, the tangential velocity has a net magnification effect, while in A < 0 models, the tangential velocity has a net suppression effect.

  19. A two-fluid model for relativistic heat conduction

    SciTech Connect

    López-Monsalvo, César S.

    2014-01-14

    Three years ago it was presented in these proceedings the relativistic dynamics of a multi-fluid system together with various applications to a set of topical problems [1]. In this talk, I will start from such dynamics and present a covariant formulation of relativistic thermodynamics which provides us with a causal constitutive equation for the propagation of heat in a relativistic setting.

  20. The relativistic Doppler broadening of the line absorption profile

    NASA Astrophysics Data System (ADS)

    Kichenassamy, S.; Krikorian, R.; Nikogosian, A.

    1982-06-01

    The classical results of Doppler broadening of the line absorption profile are generalized to a relativistic gas in thermal equilibrium by taking into account the relativistic variance of the volume absorption coefficients of the gas, as derived by L. H. Thomas. This variance produces a small correction, even in the non-relativistic approximation.

  1. Rare Relativistic Configuration Interaction Calculations

    NASA Astrophysics Data System (ADS)

    Dinov, Konstantin Dimitrov

    1995-01-01

    Valence shell Relativistic Configuration Interaction (RCI) Calculations for several Rare Earth elements resulted the following electron affinities: (1) Ce^ - 6p attachment to the 4f 5d 6s^2 ^1G_sp{4 }{circ} ground state: (2J,EA) = (9,259 meV), (7,147 meV), [7_ {rm first exc.},55 rm meV], (5,105 meV), (3,43 meV). The electron affinity of the 5d attachment in 4f 5d^2 6s^2 ^5H _{7/2} is 178 meV. (2) Pr ^- 6p attachment to the 4f^3 6s^2 ^4I_sp {9/2}{circ} ground state gives 128 meV for the 4f^3 6s^2 6p J = 5 state (^5K 60%), and 110 meV for the J = 4 state (^5I 42%). No evidence for 5d attachment was found. (3) U^- 7p attachment to the 5f ^3 6d 7s^2 ^5L _sp{6}{circ} ground state gives: 175 meV for the 2J = 13 state (^6M 54%). No other 7p or 6d bound states were found. The hyperfine structure constants for the 5f^3 6d 7s^2 7p, 2J = 13 state are A = -72.4 MHz, B = 2644 MHz. No evidence is found to support f attachment in these species. We investigated two low lying 4f ^2 thresholds in Ce, to which one could attach s or p electron, but neither attachment gives enough energy to bind the negative ion. The missing core-valence effects may reduce the EAs by 0.06 eV, based on the difference between the theoretical predictions and experimental measurements for the electron affinity of Strontium. These results correspond to the observed negative ion yields: high for Ce^ -, moderate for Pr^-, and small for U^-.. The REDUCE method was extensively used for the U^- case. The current version of the RCI program allows up to 7 000 vectors (10M elements) in RAM. The enhancement of the computer programs is by a speed factor of 6, and 7 times bigger matrices. A parallel version of the RCI programs was developed. All of these systems are unbound at the MCDF level (single manifold). By far the biggest contributor to the binding is nsto (n-1)d correlation, while the biggest unbinding comes from ns^2 to np^2 correlation. Other important correlations are: ns^2to (n-1)d^2, (n-1)d nsto np^2 & np

  2. Oxidative addition of hydrogen halides and dihalogens to Pd. Trends in reactivity and relativistic effects.

    PubMed

    de Jong, G Theodoor; Kovacs, Attila; Bickelhaupt, F Matthias

    2006-06-29

    We have theoretically studied the oxidative addition of HX and X(2) to palladium for X = F, Cl, Br, I and At, using both nonrelativistic and ZORA-relativistic density functional theory at BLYP/QZ4P. The purpose is 3-fold: (i) to obtain a set of consistent potential energy surfaces (PESs) to infer accurate trends in reactivity for simple, archetypal oxidative addition reactions; (ii) to assess how relativistic effects modify these trends along X = F, Cl, Br, I and At; and (iii) to rationalize the trends in reactivity in terms of the reactants' molecular-orbital (MO) electronic structure and the H-X and X-X bond strengths. For the latter, we provide full Dirac-Coulomb CCSD(T) benchmarks. All oxidative additions to Pd are exothermic and have a negative overall barrier, except that of HF which is approximately thermoneutral and has a positive overall barrier. The activation barriers of the HX oxidative additions decrease systematically as X descends in group 17 of the periodic table; those of X(2) first increase, from F to Cl, but then also decrease further down group 17. On the other hand, HX and X(2) show clearly opposite trends regarding the heat of reaction: that of HX becomes more exothermic and that of X(2) less exothermic as X descends in group 17. Relativistic effects can be as large as 15-20 kcal/mol but they do not change the qualitative trends. Interestingly, the influence of relativistic effects on activation barriers and heats of reaction decreases for the heavier halogens due to counteracting relativistic effects in palladium and the halogens. PMID:16789784

  3. Relativistic electron precipitation during geomagnetic storm time in the years 2006-2010

    NASA Astrophysics Data System (ADS)

    Glesnes Ødegaard, Linn-Kristine; Nesse Tyssøy, Hilde; Sandanger, Marit irene; Stadsnes, Johan; Søraas, Finn

    2015-04-01

    The processes leading to acceleration or loss of relativistic electrons in the magnetosphere during geomagnetic storm time have yet to be fully understood, and whether a geomagnetic storm will lead to enhanced or depleted fluxes of relativistic electrons can not be known in advance. Relativistic Electron Precipitation (REP) can penetrate deep into the atmosphere and influence composition and dynamics. To study the effect of REP upon the atmosphere, the energy and intensity of the electrons need to be accurately represented. We use satellite measurements of electrons with energies E>300 keV and E>1000 keV to study the behaviour of these electron populations during geomagnetic storms. We use the MEPED detectors on board the POES satellites NOAA-17, NOAA-18, MetOp-02 and NOAA-19, where the vertical telescope measures precipitated flux, and the horizontal telescope trapped flux at satellite altitude (ca 850 km). Using a newly developed technique, we can derive the flux of electrons depositing their energy in the atmosphere from the pair of detectors on each satellite. 75 isolated storms were identified in the period 2006-2010. The storms include both typical CME driven storms, and weak long duration storms driven by CIRs. Each storm was divided into pre-storm phase, main phase and recovery phase, and the flux of relativistic electrons was monitored through the storms. By combining the measurements from several satellites, we obtain a close to global view of the relativistic electron fluxes, enabling us to study the relationship between the REP and different geomagnetic indices and solar wind drivers.

  4. Improved modeling of relativistic collisions and collisional ionization in particle-in-cell codes

    SciTech Connect

    Perez, F.; Gremillet, L.; Decoster, A.; Drouin, M.; Lefebvre, E.

    2012-08-15

    An improved Monte Carlo collisional scheme modeling both elastic and inelastic interactions has been implemented into the particle-in-cell code CALDER[E. Lefebvre et al., Nucl. Fusion 43, 629 (2003)]. Based on the technique proposed by Nanbu and Yonemura [J. Comput. Phys. 145, 639 (1998)] allowing to handle arbitrarily weighted macro-particles, this binary collision scheme uses a more compact and accurate relativistic formulation than the algorithm recently worked out by Sentoku and Kemp [J. Comput. Phys. 227, 6846 (2008)]. Our scheme is validated through several test cases, demonstrating, in particular, its capability of modeling the electrical resistivity and stopping power of a solid-density plasma over a broad parameter range. A relativistic collisional ionization scheme is developed within the same framework, and tested in several physical scenarios. Finally, our scheme is applied in a set of integrated particle-in-cell simulations of laser-driven fast electron transport.

  5. Relativistic scattering with a spatially dependent effective mass in the Dirac equation

    SciTech Connect

    Alhaidari, A. D.; Bahlouli, H.; Abdelmonem, M. S.; Al-Hasan, A.

    2007-06-15

    We formulate a relativistic algebraic method of scattering for systems with spatially dependent mass based on the J-matrix method. The reference Hamiltonian is the three-dimensional Dirac Hamiltonian but with a mass that is position-dependent with a constant asymptotic limit. Additionally, this effective mass distribution is locally represented in a finite dimensional function subspace. The spinor couples to spherically symmetric vector and pseudo scalar potentials that are short-range such that they are accurately represented by their matrix elements in the same finite dimensional subspace. We calculate the relativistic phase shift as a function of energy for a given configuration and study the effect of spatial variation of the mass on the energy resonance structure.

  6. High energy Coulomb-scattered electrons for relativistic particle beam diagnostics

    NASA Astrophysics Data System (ADS)

    Thieberger, P.; Altinbas, Z.; Carlson, C.; Chasman, C.; Costanzo, M.; Degen, C.; Drees, K. A.; Fischer, W.; Gassner, D.; Gu, X.; Hamdi, K.; Hock, J.; Marusic, A.; Miller, T.; Minty, M.; Montag, C.; Luo, Y.; Pikin, A. I.; White, S. M.

    2016-04-01

    A new system used for monitoring energetic Coulomb-scattered electrons as the main diagnostic for accurately aligning the electron and ion beams in the new Relativistic Heavy Ion Collider (RHIC) electron lenses is described in detail. The theory of electron scattering from relativistic ions is developed and applied to the design and implementation of the system used to achieve and maintain the alignment. Commissioning with gold and 3He beams is then described as well as the successful utilization of the new system during the 2015 RHIC polarized proton run. Systematic errors of the new method are then estimated. Finally, some possible future applications of Coulomb-scattered electrons for beam diagnostics are briefly discussed.

  7. RAISHIN: A High-Resolution Three-Dimensional General Relativistic Magnetohydrodynamics Code

    NASA Technical Reports Server (NTRS)

    Mizuno, Yosuke; Nishikawa, Ken-Ichi; Koide, Shinji; Hardee, Philip; Fishman, Gerald J.

    2006-01-01

    We have developed a new three-dimensional general relativistic magnetohydrodynamic (GRMHD) code, RAISHIN, using a conservative, high resolution shock-capturing scheme. The numerical fluxes are calculated using the Harten, Lax, & van Leer (HLL) approximate Riemann solver scheme. The flux-interpolated, constrained transport scheme is used to maintain a divergence-free magnetic field. In order to examine the numerical accuracy and the numerical efficiency, the code uses four different reconstruction methods: piecewise linear methods with Minmod and MC slope-limiter function, convex essentially non-oscillatory (CENO) method, and piecewise parabolic method (PPM) using multistep TVD Runge-Kutta time advance methods with second and third-order time accuracy. We describe code performance on an extensive set of test problems in both special and general relativity. Our new GRMHD code has proven to be accurate in second order and has successfully passed with all tests performed, including highly relativistic and magnetized cases in both special and general relativity.

  8. Relativistic model of secondary-electron energy spectra in electron-impact ionization

    SciTech Connect

    Miller, J.H. ); Manson, S.T. )

    1991-10-01

    A relativistic model for differential electron-impact-ionization cross sections that allows the energy spectrum of secondary electrons to be calculated over a wide range of primary-electron energies is presented. The semiempirical method requires only experimental total ionization cross sections and optical oscillator strengths for the target species of interest, but other information, if available, can be incorporated to make the formulation still more accurate. Results for ionization of helium indicate that the lower limit on primary-electron energy for application of the model is about 100 eV. The simple analytic form of the model facilitates investigation of the regions of the secondary-electron energy spectrum where relativistic effects are important.

  9. Relativistic Quantum Mechanics and Field Theory

    NASA Astrophysics Data System (ADS)

    Gross, Franz

    1999-04-01

    An accessible, comprehensive reference to modern quantum mechanics and field theory. In surveying available books on advanced quantum mechanics and field theory, Franz Gross determined that while established books were outdated, newer titles tended to focus on recent developments and disregard the basics. Relativistic Quantum Mechanics and Field Theory fills this striking gap in the field. With a strong emphasis on applications to practical problems as well as calculations, Dr. Gross provides complete, up-to-date coverage of both elementary and advanced topics essential for a well-rounded understanding of the field. Developing the material at a level accessible even to newcomers to quantum mechanics, the book begins with topics that every physicist should know-quantization of the electromagnetic field, relativistic one body wave equations, and the theoretical explanation of atomic decay. Subsequent chapters prepare readers for advanced work, covering such major topics as gauge theories, path integral techniques, spontaneous symmetry breaking, and an introduction to QCD, chiral symmetry, and the Standard Model. A special chapter is devoted to relativistic bound state wave equations-an important topic that is often overlooked in other books. Clear and concise throughout, Relativistic Quantum Mechanics and Field Theory boasts examples from atomic and nuclear physics as well as particle physics, and includes appendices with background material. It is an essential reference for anyone working in quantum mechanics today.

  10. Kinetic foundations of relativistic dissipative fluid dynamics

    NASA Astrophysics Data System (ADS)

    Denicol, G. S.

    2014-12-01

    In this contribution we discuss in detail the most widespread formalisms employed to derive relativistic dissipative fluid dynamics from the Boltzmann equation: Chapman-Enskog expansion and Israel-Stewart theory. We further point out the drawbacks of each theory and explain possible ways to circumvent them. Recent developments in the derivation of fluid dynamics from the Boltzmann equation are also discussed.

  11. Flux-limited diffusion with relativistic corrections

    SciTech Connect

    Pomraning, G.C.

    1983-03-15

    A recently reported flux-limited diffusion theory is extended to include relativistic terms, correct to first order in the fluid velocity. We show that this diffusion theory is fully flux limited, and yields the correct result for the radiative flux in the classical diffusion limit, namely a Fick's law component plus a v/c convective term.

  12. Relativistic equations with fractional and pseudodifferential operators

    SciTech Connect

    Babusci, D.; Dattoli, G.; Quattromini, M.

    2011-06-15

    In this paper we use different techniques from the fractional and pseudo-operators calculus to solve partial differential equations involving operators with noninteger exponents. We apply the method to equations resembling generalizations of the heat equations and discuss the possibility of extending the procedure to the relativistic Schroedinger and Dirac equations.

  13. Consistent resolution of some relativistic quantum paradoxes

    SciTech Connect

    Griffiths, Robert B.

    2002-12-01

    A relativistic version of the (consistent or decoherent) histories approach to quantum theory is developed on the basis of earlier work by Hartle, and used to discuss relativistic forms of the paradoxes of spherical wave packet collapse, Bohm's formulation of the Einstein-Podolsky-Rosen paradox, and Hardy's paradox. It is argued that wave function collapse is not needed for introducing probabilities into relativistic quantum mechanics, and in any case should never be thought of as a physical process. Alternative approaches to stochastic time dependence can be used to construct a physical picture of the measurement process that is less misleading than collapse models. In particular, one can employ a coarse-grained but fully quantum-mechanical description in which particles move along trajectories, with behavior under Lorentz transformations the same as in classical relativistic physics, and detectors are triggered by particles reaching them along such trajectories. States entangled between spacelike separate regions are also legitimate quantum descriptions, and can be consistently handled by the formalism presented here. The paradoxes in question arise because of using modes of reasoning which, while correct for classical physics, are inconsistent with the mathematical structure of quantum theory, and are resolved (or tamed) by using a proper quantum analysis. In particular, there is no need to invoke, nor any evidence for, mysterious long-range superluminal influences, and thus no incompatibility, at least from this source, between relativity theory and quantum mechanics.

  14. Relativistic atomic physics at the SSC

    SciTech Connect

    1990-12-31

    This report discusses the following proposed work for relativistic atomic physics at the Superconducting Super Collider: Beam diagnostics; atomic physics research; staffing; education; budget information; statement concerning matching funds; description and justification of major items of equipment; statement of current and pending support; and assurance of compliance.

  15. Instabilities in a Relativistic Viscous Fluid

    NASA Astrophysics Data System (ADS)

    Corona-Galindo, M. G.; Klapp, J.; Vazquez, A.

    1990-11-01

    RESUMEN. Las ecuaciones hidrodinamicas de un fluido imperfecto relativista son resueltas, y los modos hidrodinamicos son analizados con el prop6sito de estabiecer correlaciones con las estructuras cosmol6gicas. ABSTRACT The hydrodynamical equations of a relativistic imperfect fluid are solved, and the hydrodynamical modes are analysed with the aim to establish correlations with cosmological structures. Ke, words: COSMOLOGY - HYDRODYNAMICS - RELATIVITY

  16. Asymptotic theory of relativistic, magnetized jets

    SciTech Connect

    Lyubarsky, Yuri

    2011-01-15

    The structure of a relativistically hot, strongly magnetized jet is investigated at large distances from the source. Asymptotic equations are derived describing collimation and acceleration of the externally confined jet. Conditions are found for the transformation of the thermal energy into the fluid kinetic energy or into the Poynting flux. Simple scalings are presented for the jet collimation angle and Lorentz factors.

  17. A Quantum Relativistic Prisoner's Dilemma Cellular Automaton

    NASA Astrophysics Data System (ADS)

    Alonso-Sanz, Ramón; Carvalho, Márcio; Situ, Haozhen

    2016-06-01

    The effect of variable entangling on the dynamics of a spatial quantum relativistic formulation of the iterated prisoner's dilemma game is studied in this work. The game is played in the cellular automata manner, i.e., with local and synchronous interaction. The game is assessed in fair and unfair contests.

  18. On Radiative Acceleration of Relativistic Jets

    NASA Astrophysics Data System (ADS)

    Inoue, S.; Takahara, F.

    1997-10-01

    The formation and acceleration of relativistic jets by radiative forces in black hole systems are investigated. Under a variety of circumstances, we calculate the bulk acceleration and radiative cooling of a confined plasma cell, immersed in different types of radiation fields and interacting by Compton scattering. Both non-relativistic (cold) and relativistic (hot) jet plasma, comprising mixtures of electron-proton and electron-positron components, are treated. We pay attention to some conceivable effects, previously neglected, which may possibly enhance the bulk acceleration; among them are an anisotropically radiating accretion disk surface, beamed secondary radiation from the inner jet, and scattering in the energy dependent Klein-Nishina regime. Our results are discussed in the context of relativistic jets in active galactic nuclei and Galactic black hole candidates, and the conditions necessary for successfully reproducing their observed properties are highlighted. In particular, the velocities of the recently discovered superluminal jets in Galactic black hole candidates (Lorentz factors of Γ ~ 2.5) are readily and very robustly accounted for if the jet is composed primarily of electron-positron pairs and the disk luminosity is near the Eddington value; the jet kinetic power can be consistent with optical depth and pair annihilation constraints. On the other hand, severe difficulty is met in attaining the velocities of AGN jets (Γ ~ 10), which can only be realized when a significant amount of beamed secondary radiation is present. We also contemplate additional important issues, such as global energetics.

  19. Relativistic quantum corrections to laser wakefield acceleration.

    PubMed

    Zhu, Jun; Ji, Peiyong

    2010-03-01

    The influence of quantum effects on the interaction of intense laser fields with plasmas is investigated by using a hydrodynamic model based on the framework of the relativistic quantum theory. Starting from the covariant Wigner function and Dirac equation, the hydrodynamic equations for relativistic quantum plasmas are derived. Based on the relativistic quantum hydrodynamic equations and Poisson equation, the perturbations of electron number densities and the electric field of the laser wakefield containing quantum effects are deduced. It is found that the corrections generated by the quantum effects to the perturbations of electron number densities and the accelerating field of the laser wakefield cannot be neglected. Quantum effects will suppress laser wakefields, which is a classical manifestation of quantum decoherence effects, however, the contribution of quantum effects for the laser wakefield correction will been partially counteracted by the relativistic effects. The analysis also reveals that quantum effects enlarge the effective frequencies of plasmas, and the quantum behavior appears a screening effect for plasma electrons. PMID:20365881

  20. Relativistic quantum corrections to laser wakefield acceleration

    SciTech Connect

    Zhu Jun; Ji Peiyong

    2010-03-15

    The influence of quantum effects on the interaction of intense laser fields with plasmas is investigated by using a hydrodynamic model based on the framework of the relativistic quantum theory. Starting from the covariant Wigner function and Dirac equation, the hydrodynamic equations for relativistic quantum plasmas are derived. Based on the relativistic quantum hydrodynamic equations and Poisson equation, the perturbations of electron number densities and the electric field of the laser wakefield containing quantum effects are deduced. It is found that the corrections generated by the quantum effects to the perturbations of electron number densities and the accelerating field of the laser wakefield cannot be neglected. Quantum effects will suppress laser wakefields, which is a classical manifestation of quantum decoherence effects, however, the contribution of quantum effects for the laser wakefield correction will been partially counteracted by the relativistic effects. The analysis also reveals that quantum effects enlarge the effective frequencies of plasmas, and the quantum behavior appears a screening effect for plasma electrons.

  1. Constraining relativistic models through heavy ion collisions

    SciTech Connect

    Menezes, D. P.; Providencia, C.; Chiapparini, M.; Bracco, M. E.; Delfino, A.; Malheiro, M.

    2007-12-15

    Relativistic models can be successfully applied to the description of compact star properties in nuclear astrophysics as well as to nuclear matter and finite nuclei properties, these studies taking place at low and moderate temperatures. Nevertheless, all results are model dependent, and so far it is unclear whether some of them should be discarded. Moreover, in the regime of hot hadronic matter, very few calculations exist using these relativistic models, in particular when applied to particle yields in heavy ion collisions. A very important investigation is the simulation of a supernova explosion that is based on the construction of an adequate equation of state that needs to be valid within very large ranges of temperatures (0 to 100 MeV at least) and densities (very low to ten times the nuclear saturation density at least). In the present work, we comment on the known constraints that can help the selection of adequate models in this wide regime and investigate the main differences that arise when the particle production during a Au+Au collision at the BNL Relativistic Heavy Ion Collider is calculated with different relativistic models. We conclude that most of the models investigated in the present work give a very good overall description of the data and make predictions for not yet measured particle ratios.

  2. Relativistic shock propagation in nonuniform media

    NASA Astrophysics Data System (ADS)

    Gnatyk, B. I.

    1985-10-01

    Strong shocks will propagate in much the same way whether they are non- or ultrarelativistic. An approximate law is proposed to describe the motion of a strong, adiabatic, arbitrarily relativistic shock through an initially nonrelativistic medium having any desired density distribution.

  3. Computational relativistic quantum dynamics and its application to relativistic tunneling and Kapitza-Dirac scattering

    NASA Astrophysics Data System (ADS)

    Bauke, Heiko; Klaiber, Michael; Yakaboylu, Enderalp; Hatsagortsyan, Karen Z.; Ahrens, Sven; Müller, Carsten; Keitel, Christoph H.

    2013-05-01

    Computational methods are indispensable to study the quantum dynamics of relativistic light-matter interactions in parameter regimes where analytical methods become inapplicable. We present numerical methods for solving the time-dependent Dirac equation and the time-dependent Klein-Gordon equation and their implementation on high performance graphics cards. These methods allow us to study tunneling from hydrogen-like highly charged ions in strong laser fields and Kapitza-Dirac scattering in the relativistic regime.

  4. The prediction of the nuclear quadrupole splitting of 119Sn Mössbauer spectroscopy data by scalar relativistic DFT calculations.

    PubMed

    Krogh, Jesper W; Barone, Giampaolo; Lindh, Roland

    2006-06-23

    The electric field gradient components for the tin nucleus of 34 tin compounds of experimentally known structures and (119)Sn Mössbauer spectroscopy parameters were computed at the scalar relativistic density functional theory level of approximation. The theoretical values of the electric field gradient components were used to determine a quantity, V, which is proportional to the nuclear quadrupole splitting parameter (DeltaE). In a subsequent linear regression analysis the effective nuclear quadrupole moment, Q, was evaluated. The value of (11.9+/-0.1) fm(2) is a significant improvement over the non-relativistic result of (15.2+/-4.4) fm(2) and is in agreement with the experimental value of (10.9+/-0.8) fm(2). The average mean square error DeltaE(calcd)-DeltaE(exptl)=+/-0.3 mm s(-1) is a factor of two smaller than in the non-relativistic case. Thus, the approach has a quality which provides accurate support for the structure interpretation by (119)Sn spectroscopy. It was noted that geometry optimization at the relativistic level does not significantly increase the quality of the results compared with non-relativistic optimized structures. The accuracy in the approach called on us to consider the singlet-triplet state nature of the electronic structure of one of the investigated compounds. PMID:16671047

  5. Relativistic decay widths of autoionization processes: The relativistic FanoADC-Stieltjes method

    SciTech Connect

    Fasshauer, Elke; Kolorenč, Přemysl; Pernpointner, Markus

    2015-04-14

    Electronic decay processes of ionized systems are, for example, the Auger decay or the Interatomic/ Intermolecular Coulombic Decay. In both processes, an energetically low lying vacancy is filled by an electron of an energetically higher lying orbital and a secondary electron is instantaneously emitted to the continuum. Whether or not such a process occurs depends both on the energetic accessibility and the corresponding lifetime compared to the lifetime of competing decay mechanisms. We present a realization of the non-relativistically established FanoADC-Stieltjes method for the description of autoionization decay widths including relativistic effects. This procedure, being based on the Algebraic Diagrammatic Construction (ADC), was adapted to the relativistic framework and implemented into the relativistic quantum chemistry program package Dirac. It is, in contrast to other existing relativistic atomic codes, not limited to the description of autoionization lifetimes in spherically symmetric systems, but is instead also applicable to molecules and clusters. We employ this method to the Auger processes following the Kr3d{sup −1}, Xe4d{sup −1}, and Rn5d{sup −1} ionization. Based on the results, we show a pronounced influence of mainly scalar-relativistic effects on the decay widths of autoionization processes.

  6. Nonlinear magnetosonic waves in dense plasmas with non-relativistic and ultra-relativistic degenerate electrons

    SciTech Connect

    Hussain, S.; Mahmood, S.; Rehman, Aman-ur-

    2014-11-15

    Linear and nonlinear propagation of magnetosonic waves in the perpendicular direction to the ambient magnetic field is studied in dense plasmas for non-relativistic and ultra-relativistic degenerate electrons pressure. The sources of nonlinearities are the divergence of the ions and electrons fluxes, Lorentz forces on ions and electrons fluids and the plasma current density in the system. The Korteweg-de Vries equation for magnetosonic waves propagating in the perpendicular direction of the magnetic field is derived by employing reductive perturbation method for non-relativistic as well as ultra-relativistic degenerate electrons pressure cases in dense plasmas. The plots of the magnetosonic wave solitons are also shown using numerical values of the plasma parameters such a plasma density and magnetic field intensity of the white dwarfs from literature. The dependence of plasma density and magnetic field intensity on the magnetosonic wave propagation is also pointed out in dense plasmas for both non-relativistic and ultra-relativistic degenerate electrons pressure cases.

  7. 3D Relativistic Magnetohydrodynamic Simulations of Magnetized Spine-Sheath Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Mizuno, Yosuke; Hardee, Philip; Nishikawa, Ken-Ichi

    2006-01-01

    Numerical simulations of weakly magnetized and strongly magnetized relativistic jets embedded in a weakly magnetized and strongly magnetized stationary or weakly relativistic (v = c/2) sheath have been performed. A magnetic field parallel to the flow is used in these simulations performed by the new GRMHD numerical code RAISHIN used in its RMHD configuration. In the numerical simulations the Lorentz factor gamma = 2.5 jet is precessed to break the initial equilibrium configuration. In the simulations sound speeds are less than or equal to c/the square root of 3 in the weakly magnetized simulations and less than or equal to 0.56 c in the strongly magnetized simulations. The Alfven wave speed is less than or equal to 0.07 c in the weakly magnetized simulations and less than or equal to 0.56 c in the strongly magnetized simulations. The results of the numerical simulations are compared to theoretical predictions from a normal mode analysis of the linearized relativistic magnetohydrodynamic (RMHD) equations capable of describing a uniform axially magnetized cylindrical relativistic jet embedded in a uniform axially magnetized relativistically moving sheath. The theoretical dispersion relation allows investigation of effects associated with maximum possible sound speeds, Alfven wave speeds near light speed and relativistic sheath speeds. The prediction of increased stability of the weakly magnetized system resulting from c/2 sheath speeds and the stabilization of the strongly magnetized system resulting from c/2 sheath speeds is verified by the numerical simulation results.

  8. Study of quantum spin correlations of relativistic electron pairs - Testing nonlocality of relativistic quantum mechanics

    NASA Astrophysics Data System (ADS)

    Bodek, K.; Caban, P.; Ciborowski, J.; Enders, J.; Köhler, A.; Kozela, A.; Rembieliński, J.; Rozpedzik, D.; Włodarczyk, M.; Zejma, J.

    2013-11-01

    The Polish-German project QUEST aims at studying relativistic quantum spin correlations of the Einstein-Rosen-Podolsky-Bohm type, through measurement of the correlation function and the corresponding probabilities for relativistic electron pairs. The results will be compared to theoretical predictions obtained by us within the framework of relativistic quantum mechanics, based on assumptions regarding the form of the relativistic spin operator. Agreement or divergence will be interpreted in the context of non-uniqueness of the relativistic spin operator in quantum mechanics as well as dependence of the correlation function on the choice of observables representing the spin. Pairs of correlated electrons will originate from the Mo/ller scattering of polarized 15 MeV electrons provided by the superconducting Darmstadt electron linear accelerator S-DALINAC, TU Darmstadt, incident on a Be target. Spin projections will be determined using the Mott polarimetry technique. Measurements (starting 2013) are planned for longitudinal and transverse beam polarizations and different orientations of the beam polarization vector w.r.t. the Mo/ller scattering plane. This is the first project to study relativistic spin correlations for particles with mass.

  9. Study of quantum spin correlations of relativistic electron pairs - Testing nonlocality of relativistic quantum mechanics

    SciTech Connect

    Bodek, K.; Rozpędzik, D.; Zejma, J.; Caban, P.; Rembieliński, J.; Włodarczyk, M.; Enders, J.; Köhler, A.; Kozela, A.

    2013-11-07

    The Polish-German project QUEST aims at studying relativistic quantum spin correlations of the Einstein-Rosen-Podolsky-Bohm type, through measurement of the correlation function and the corresponding probabilities for relativistic electron pairs. The results will be compared to theoretical predictions obtained by us within the framework of relativistic quantum mechanics, based on assumptions regarding the form of the relativistic spin operator. Agreement or divergence will be interpreted in the context of non-uniqueness of the relativistic spin operator in quantum mechanics as well as dependence of the correlation function on the choice of observables representing the spin. Pairs of correlated electrons will originate from the Mo/ller scattering of polarized 15 MeV electrons provided by the superconducting Darmstadt electron linear accelerator S-DALINAC, TU Darmstadt, incident on a Be target. Spin projections will be determined using the Mott polarimetry technique. Measurements (starting 2013) are planned for longitudinal and transverse beam polarizations and different orientations of the beam polarization vector w.r.t. the Mo/ller scattering plane. This is the first project to study relativistic spin correlations for particles with mass.

  10. Isospin flip as a relativistic effect: NN interactions

    NASA Technical Reports Server (NTRS)

    Buck, W. W.

    1993-01-01

    Results are presented of an analytic relativistic calculation of a OBE nucleon-nucleon (NN) interaction employing the Gross equation. The calculation consists of a non-relativistic reduction that keeps the negative energy states. The result is compared to purely non-relativistic OBEP results and the relativistic effects are separated out. One finds that the resulting relativistic effects are expressable as a power series in (tau(sub 1))(tau(sub 2)) that agrees, qualitatively, with NN scattering. Upon G-parity transforming this NN potential, one obtains, qualitatively, a short range NN spectroscopy in which the S-states are the lowest states.

  11. Relativistically strong Langmuir turbulence in the kinetic regime

    SciTech Connect

    Liu, X. L.; Liu, S. Q.; Li, X. Q.

    2011-08-15

    Using a kinetic description, the relativistically strong Langmuir turbulence is investigated, which has considered the nonlinear wave-wave, wave-particle interactions and the relativistic effects of electrons. The relativistic Zakharov equations have been obtained. On the basis of these equations, dynamics of collapse has been studied. It is shown that the field strength of relativistic Langmuir plasmons will increase and the ponderomotive expulsion of particles gives rise to the formation of density caviton during the collapsing, which is useful for understanding the natural structural element of relativistically strong Langmuir turbulence.

  12. A general relativistic model for free-fall absolute gravimeters

    NASA Astrophysics Data System (ADS)

    Tan, Yu-Jie; Shao, Cheng-Gang; Li, Jia; Hu, Zhong-Kun

    2016-04-01

    Although the relativistic manifestations of gravitational fields in gravimetry were first studied 40 years ago, the relativistic effects combined with free-fall absolute gravimeters have rarely been considered. In light of this, we present a general relativistic model for free-fall absolute gravimeters in a local-Fermi coordinates system, where we focus on effects related to the measuring devices: relativistic transverse Doppler effects, gravitational redshift effects and Earth’s rotation effects. Based on this model, a general relativistic expression of the measured gravity acceleration is obtained.

  13. FAST TRACK COMMUNICATION Accurate estimate of α variation and isotope shift parameters in Na and Mg+

    NASA Astrophysics Data System (ADS)

    Sahoo, B. K.

    2010-12-01

    We present accurate calculations of fine-structure constant variation coefficients and isotope shifts in Na and Mg+ using the relativistic coupled-cluster method. In our approach, we are able to discover the roles of various correlation effects explicitly to all orders in these calculations. Most of the results, especially for the excited states, are reported for the first time. It is possible to ascertain suitable anchor and probe lines for the studies of possible variation in the fine-structure constant by using the above results in the considered systems.

  14. Crystallization and collapse in relativistically degenerate matter

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2013-04-15

    In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (M{sub Ch} Asymptotically-Equal-To 1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

  15. Spin dynamics in relativistic light-matter interaction

    NASA Astrophysics Data System (ADS)

    Bauke, Heiko; Ahrens, Sven; Keitel, Christoph H.; Grobe, Rainer

    2015-05-01

    Various spin effects are expected to become observable in light-matter interaction at relativistic intensities. Relativistic quantum mechanics equipped with a suitable relativistic spin operator forms the theoretical foundation for describing these effects. Various proposals for relativistic spin operators have been offered by different authors, which are presented in a unified way. As a result of the operators' mathematical properties only the Foldy-Wouthuysen operator and the Pryce operator qualify as possible proper relativistic spin operators. The ground states of highly charged hydrogen-like ions can be utilized to identify a legitimate relativistic spin operator experimentally. Subsequently, the Foldy-Wouthuysen spin operator is employed to study electron-spin precession in high-intensity standing light waves with elliptical polarization. For a correct theoretical description of the predicted electron-spin precession relativistic effects due to the spin angular momentum of the electromagnetic wave has to be taken into account even in the limit of low intensities.

  16. RANKINE-HUGONIOT RELATIONS IN RELATIVISTIC COMBUSTION WAVES

    SciTech Connect

    Gao Yang; Law, Chung K.

    2012-12-01

    As a foundational element describing relativistic reacting waves of relevance to astrophysical phenomena, the Rankine-Hugoniot relations classifying the various propagation modes of detonation and deflagration are analyzed in the relativistic regime, with the results properly degenerating to the non-relativistic and highly relativistic limits. The existence of negative-pressure downstream flows is noted for relativistic shocks, which could be of interest in the understanding of the nature of dark energy. Entropy analysis for relativistic shock waves is also performed for relativistic fluids with different equations of state (EoS), denoting the existence of rarefaction shocks in fluids with adiabatic index {Gamma} < 1 in their EoS. The analysis further shows that weak detonations and strong deflagrations, which are rare phenomena in terrestrial environments, are expected to exist more commonly in astrophysical systems because of the various endothermic reactions present therein. Additional topics of relevance to astrophysical phenomena are also discussed.

  17. Accurate transition rates for intercombination lines of singly ionized nitrogen

    SciTech Connect

    Tayal, S. S.

    2011-01-15

    The transition energies and rates for the 2s{sup 2}2p{sup 2} {sup 3}P{sub 1,2}-2s2p{sup 3} {sup 5}S{sub 2}{sup o} and 2s{sup 2}2p3s-2s{sup 2}2p3p intercombination transitions have been calculated using term-dependent nonorthogonal orbitals in the multiconfiguration Hartree-Fock approach. Several sets of spectroscopic and correlation nonorthogonal functions have been chosen to describe adequately term dependence of wave functions and various correlation corrections. Special attention has been focused on the accurate representation of strong interactions between the 2s2p{sup 3} {sup 1,3}P{sub 1}{sup o} and 2s{sup 2}2p3s {sup 1,3}P{sub 1}{sup o}levels. The relativistic corrections are included through the one-body mass correction, Darwin, and spin-orbit operators and two-body spin-other-orbit and spin-spin operators in the Breit-Pauli Hamiltonian. The importance of core-valence correlation effects has been examined. The accuracy of present transition rates is evaluated by the agreement between the length and velocity formulations combined with the agreement between the calculated and measured transition energies. The present results for transition probabilities, branching fraction, and lifetimes have been compared with previous calculations and experiments.

  18. Accurate ab initio vibrational energies of methyl chloride

    SciTech Connect

    Owens, Alec; Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan; Thiel, Walter

    2015-06-28

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH{sub 3}{sup 35}Cl and CH{sub 3}{sup 37}Cl. The respective PESs, CBS-35{sup  HL}, and CBS-37{sup  HL}, are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY {sub 3}Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35{sup  HL} and CBS-37{sup  HL} PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm{sup −1}, respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH{sub 3}Cl without empirical refinement of the respective PESs.

  19. Accurate ab initio vibrational energies of methyl chloride.

    PubMed

    Owens, Alec; Yurchenko, Sergei N; Yachmenev, Andrey; Tennyson, Jonathan; Thiel, Walter

    2015-06-28

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH3 (35)Cl and CH3 (37)Cl. The respective PESs, CBS-35( HL), and CBS-37( HL), are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY 3Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35( HL) and CBS-37( HL) PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm(-1), respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH3Cl without empirical refinement of the respective PESs. PMID:26133427

  20. Accurate ab initio vibrational energies of methyl chloride

    NASA Astrophysics Data System (ADS)

    Owens, Alec; Yurchenko, Sergei N.; Yachmenev, Andrey; Tennyson, Jonathan; Thiel, Walter

    2015-06-01

    Two new nine-dimensional potential energy surfaces (PESs) have been generated using high-level ab initio theory for the two main isotopologues of methyl chloride, CH335Cl and CH337Cl. The respective PESs, CBS-35 HL, and CBS-37 HL, are based on explicitly correlated coupled cluster calculations with extrapolation to the complete basis set (CBS) limit, and incorporate a range of higher-level (HL) additive energy corrections to account for core-valence electron correlation, higher-order coupled cluster terms, scalar relativistic effects, and diagonal Born-Oppenheimer corrections. Variational calculations of the vibrational energy levels were performed using the computer program TROVE, whose functionality has been extended to handle molecules of the form XY 3Z. Fully converged energies were obtained by means of a complete vibrational basis set extrapolation. The CBS-35 HL and CBS-37 HL PESs reproduce the fundamental term values with root-mean-square errors of 0.75 and 1.00 cm-1, respectively. An analysis of the combined effect of the HL corrections and CBS extrapolation on the vibrational wavenumbers indicates that both are needed to compute accurate theoretical results for methyl chloride. We believe that it would be extremely challenging to go beyond the accuracy currently achieved for CH3Cl without empirical refinement of the respective PESs.

  1. Theoretical study of the nuclear spin-molecular rotation coupling for relativistic electrons and non-relativistic nuclei

    NASA Astrophysics Data System (ADS)

    Aucar, Ignacio A.; Gómez, Sergio S.; de Azúa, Martín C. Ruiz; Giribet, Claudia G.

    2012-05-01

    A theoretical study of the relation between the relativistic formulation of the nuclear magnetic shielding and spin-rotation tensors is presented. To this end a theoretical expression of the relativistic spin-rotation tensor is formulated, considering a molecular Hamiltonian of relativistic electrons and non-relativistic nuclei. Molecular rotation effects are introduced considering the terms of the Born-Oppenheimer decomposition, which couple the electrons and nuclei dynamics. The loss of the simple relation linking both spectral parameters in the non-relativistic formulation is further analyzed carrying out a perturbative expansion of relativistic effects by means of the linear response within the elimination of the small component approach. It is concluded that relativistic effects on the spin-rotation tensor are less important than those of the nuclear magnetic shielding tensor.

  2. Kinetic analysis of thermally relativistic flow with dissipation. II. Relativistic Boltzmann equation versus its kinetic models

    NASA Astrophysics Data System (ADS)

    Yano, Ryosuke; Matsumoto, Jun; Suzuki, Kojiro

    2011-06-01

    Thermally relativistic flow with dissipation was analyzed by solving the rarefied supersonic flow of thermally relativistic matter around a triangle prism by Yano and Suzuki [Phys. Rev. DPRVDAQ1550-7998 83, 023517 (2011)10.1103/PhysRevD.83.023517], where the Anderson-Witting (AW) model was used as a solver. In this paper, we solve the same problem, which was analyzed by Yano and Suzuki, using the relativistic Boltzmann equation (RBE). To solve the RBE, the conventional direct simulation Monte Carlo method for the nonrelativistic Boltzmann equation is extended to a new direct simulation Monte Carlo method for the RBE. Additionally, we solve the modified Marle (MM) model proposed by Yano-Suzuki-Kuroda for comparisons. The solution of the thermally relativistic shock layer around the triangle prism obtained using the relativistic Boltzmann equation is considered by focusing on profiles of macroscopic quantities, such as the density, velocity, temperature, heat flux and dynamic pressure along the stagnation streamline (SSL). Differences among profiles of the number density, velocity and temperature along the SSL obtained using the RBE, the AW and MM. models are described in the framework of the relativistic Navier-Stokes-Fourier law. Finally, distribution functions on the SSL obtained using the RBE are compared with those obtained using the AW and MM models. The distribution function inside the shock wave obtained using the RBE does not indicate a bimodal form, which is obtained using the AW and MM models, but a smooth deceleration of thermally relativistic matter inside a shock wave.

  3. A new quasi-relativistic approach for density functional theory based on the normalized elimination of the small component

    NASA Astrophysics Data System (ADS)

    Filatov, Michael; Cremer, Dieter

    2002-01-01

    A recently developed variationally stable quasi-relativistic method, which is based on the low-order approximation to the method of normalized elimination of the small component, was incorporated into density functional theory (DFT). The new method was tested for diatomic molecules involving Ag, Cd, Au, and Hg by calculating equilibrium bond lengths, vibrational frequencies, and dissociation energies. The method is easy to implement into standard quantum chemical programs and leads to accurate results for the benchmark systems studied.

  4. A SCILAB Program for Computing General-Relativistic Models of Rotating Neutron Stars by Implementing Hartle's Perturbation Method

    NASA Astrophysics Data System (ADS)

    Papasotiriou, P. J.; Geroyannis, V. S.

    We implement Hartle's perturbation method to the computation of relativistic rigidly rotating neutron star models. The program has been written in SCILAB (© INRIA ENPC), a matrix-oriented high-level programming language. The numerical method is described in very detail and is applied to many models in slow or fast rotation. We show that, although the method is perturbative, it gives accurate results for all practical purposes and it should prove an efficient tool for computing rapidly rotating pulsars.

  5. Relativistic virial relation for cosmological structures

    NASA Astrophysics Data System (ADS)

    Javadinezhad, Reza; Firouzjaee, Javad T.; Mansouri, Reza

    2016-01-01

    Starting with the relativistic Boltzmann equation for a system of particles defined by a distribution function, we have derived the virial relation for a spherical structure within an expanding background in the context of general relativity. This generalized form of the virial relation is then applied to the static case of a spherically symmetric structure to see the difference in the simplest case to the Newtonian relation. A relativistic mass-temperature relation for this simple case is also derived which can be applied to compact objects in astrophysics. Our general virial relation is then applied to the nonstatic case of a structure within an expanding universe where an extra term, usually missed in studies of structures in the presence of the dark energy, appears.

  6. Relativistic-microwave theory of ball lightning

    PubMed Central

    Wu, H.-C.

    2016-01-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835

  7. Adaptive Mesh Refinement Simulations of Relativistic Binaries

    NASA Astrophysics Data System (ADS)

    Motl, Patrick M.; Anderson, M.; Lehner, L.; Olabarrieta, I.; Tohline, J. E.; Liebling, S. L.; Rahman, T.; Hirschman, E.; Neilsen, D.

    2006-09-01

    We present recent results from our efforts to evolve relativistic binaries composed of compact objects. We simultaneously solve the general relativistic hydrodynamics equations to evolve the material components of the binary and Einstein's equations to evolve the space-time. These two codes are coupled through an adaptive mesh refinement driver (had). One of the ultimate goals of this project is to address the merger of a neutron star and black hole and assess the possible observational signature of such systems as gamma ray bursts. This work has been supported in part by NSF grants AST 04-07070 and PHY 03-26311 and in part through NASA's ATP program grant NAG5-13430. The computations were performed primarily at NCSA through grant MCA98N043 and at LSU's Center for Computation & Technology.

  8. Multidimensional numerical scheme for resistive relativistic magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Komissarov, Serguei S.

    2007-12-01

    The paper describes a new upwind conservative numerical scheme for special relativistic resistive magnetohydrodynamics with scalar resistivity. The magnetic field is kept approximately divergence free and the divergence of the electric field is kept consistent with the electric charge distribution via the method of Generalized Lagrange Multiplier. The hyperbolic fluxes are computed using the Harten-Lax-van Leer (HLL) prescription and the source terms are accounted via the time-splitting technique. The results of test simulations show that the scheme can handle equally well both resistive current sheets and shock waves, and thus can be a useful tool for studying phenomena of relativistic astrophysics that involve both colliding supersonic flows and magnetic reconnection.

  9. Relativistic theory of tidal Love numbers

    SciTech Connect

    Binnington, Taylor; Poisson, Eric

    2009-10-15

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  10. Formation and damping of relativistic strong shocks

    NASA Astrophysics Data System (ADS)

    Anile, A. M.; Miller, J. C.; Motta, S.

    1983-06-01

    Results are presented from a detailed study of the formation of strong relativistic shocks from simple waves and their subsequent damping. Basic results in relativistic hydrodynamics are first reviewed, and the transport equation for the shock amplitude is derived which permits the exact calculation of the characteristic damping time for an arbitrary initial shock profile. A basic formalism for the numerical treatment of the problem is set up using a Lagrangian formulation with the rest mass as a distance coordinate. Some results derived directly from the Rankine-Hugoniot relations are presented, and numerical results are given for the case of a purely compressive initial sine pulse propagating into a static uniform medium. The calculations confirm the qualitative nature of the effect fund by Liang and Baker (1977).

  11. Local supersymmetry in non-relativistic systems

    NASA Astrophysics Data System (ADS)

    Urrutia, L. F.; Zanelli, J.

    1989-10-01

    Classical and quantum non-relativistic interacting systems invariant under local supersymmetry are constructed by the method of taking square roots of the bosonic constraints which generate timelike reparameterization, leaving the action unchanged. In particular, the square root of the Schroedinger constraint is shown to be the non-relativistic limit of the Dirac constraint. Contact is made with the standard models of Supersymmetric Quantum Mechanics through the reformulation of the locally invariant systems in terms of their true degrees of freedom. Contrary to the field theory case, it is shown that the locally invariant systems are completely equivalent to the corresponding globally invariant ones, the latter being the Heisenberg picture description of the former, with respect to some fermionic time.

  12. Hydrodynamics of ultra-relativistic bubble walls

    NASA Astrophysics Data System (ADS)

    Leitao, Leonardo; Mégevand, Ariel

    2016-04-01

    In cosmological first-order phase transitions, gravitational waves are generated by the collisions of bubble walls and by the bulk motions caused in the fluid. A sizeable signal may result from fast-moving walls. In this work we study the hydrodynamics associated to the fastest propagation modes, namely, ultra-relativistic detonations and runaway solutions. We compute the energy injected by the phase transition into the fluid and the energy which accumulates in the bubble walls. We provide analytic approximations and fits as functions of the net force acting on the wall, which can be readily evaluated for specific models. We also study the back-reaction of hydrodynamics on the wall motion, and we discuss the extrapolation of the friction force away from the ultra-relativistic limit. We use these results to estimate the gravitational wave signal from detonations and runaway walls.

  13. Oscillations of rapidly rotating relativistic stars

    SciTech Connect

    Gaertig, Erich; Kokkotas, Kostas D.

    2008-09-15

    Nonaxisymmetric oscillations of rapidly rotating relativistic stars are studied using the Cowling approximation. The oscillation spectra have been estimated by Fourier transforming the evolution equations describing the perturbations. This is the first study of its kind and provides information on the effect of fast rotation on the oscillation spectra while it offers the possibility of studying the complete problem by including space-time perturbations. Our study includes both axisymmetric and nonaxisymmetric perturbations and provides limits for the onset of the secular bar mode rotational instability. We also present approximate formulas for the dependence of the oscillation spectrum from rotation. The results suggest that it is possible to extract the relativistic star's parameters from the observed gravitational wave spectrum.

  14. Relativistic electrons and whistlers in Jupiter's magnetosphere

    NASA Technical Reports Server (NTRS)

    Barbosa, D. D.; Coroniti, F. V.

    1976-01-01

    The path-integrated gain of parallel propagating whistlers driven unstable by an anisotropic distribution of relativistic electrons in the stable trapping region of Jupiter's inner magnetosphere was computed. The requirement that a gain of 3 e-foldings of power balance the power lost by imperfect reflection along the flux tube sets a stably-trapped flux of electrons which is close to the non-relativistic result. Comparison with measurements shows that observed fluxes are near the stably-trapped limit, which suggests that whistler wave intensities may be high enough to cause significant diffusion of electrons accounting for the observed reduction of phase space densities. A crude estimate of the wave intensity necessary to diffuse electrons on a radial diffusion time scale yields a lower limit for the magnetic field fluctuation intensity.

  15. Finite nucleus effects on relativistic energy corrections

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.; Faegri, Knut, Jr.

    1993-01-01

    The effect of using a finite nucleus model in quantum-chemical calculations is examined. Relativistic corrections from the first order Foldy-Wouthuysen terms are affected indirectly by the change in wavefunction, but also directly as a result of revised expressions for the Darwin and spin-orbit terms due to the change in nuclear potential. A calculation for the Rn atom indicates that the mass-velocity and Darwin corrections are much more sensitive to the finite nucleus than the non-relativistic total energy, but that the total contribution for these two terms is quite stable provided the revised form of the Darwin term is used. The spin-orbit interaction is not greatly affected by the choice of nuclear model.

  16. Fluid dynamical description of relativistic nuclear collisions

    NASA Technical Reports Server (NTRS)

    Nix, J. R.; Strottman, D.

    1982-01-01

    On the basis of both a conventional relativistic nuclear fluid dynamic model and a two fluid generalization that takes into account the interpenetration of the target and projectile upon contact, collisions between heavy nuclei moving at relativistic speeds are calculated. This is done by solving the relevant equations of motion numerically in three spatial dimensions by use of particle in cell finite difference computing techniques. The effect of incorporating a density isomer, or quasistable state, in the nuclear equation of state at three times normal nuclear density, and the effect of doubling the nuclear compressibility coefficient are studied. For the reaction 20Ne + 238U at a laboratory bombarding energy per nucleon of 393 MeV, the calculated distributions in energy and angle of outgoing charged particles are compared with recent experimental data both integrated over all impact parameters and for nearly central collisions.

  17. Relativistic klystrons for high-gradient accelerators

    SciTech Connect

    Westenskow, G.A.; Aalberts, D.P.; Boyd, J.K.; Deis, G.A.; Houck, T.L.; Orzechowski, T.J.; Ryne, R.D.; Yu, S.S. ); Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fant, K.S.; Fowkes, W.R.; Hoag, H.A.; Koontz, R.F.; Lavine, T.L.; Loew, G.A.; Miller, R.H.; Ruth, R.D.; Vlieks, A.E.; Wang, J.W. ); Haimson, J.; Mecklen

    1990-09-05

    Experimental work is being performed by collaborators at LLNL, SLAC, and LBL to investigate relativistic klystrons as a possible rf power source for future high-gradient accelerators. We have learned how to overcome or previously reported problem of high power rf pulse shortening and have achieved peak rf power levels of 330 MW using an 11.4-GHz high-gain tube with multiple output structures. In these experiments the rf pulse is of the same duration as the beam current pulse. In addition, experiments have been performed on two short sections of a high-gradient accelerator using the rf power from a relativistic klystron. An average accelerating gradient of 84 MV/m has been achieved with 80-MW of rf power.

  18. Relativistic-microwave theory of ball lightning

    NASA Astrophysics Data System (ADS)

    Wu, H.-C.

    2016-06-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

  19. Relativistic-microwave theory of ball lightning.

    PubMed

    Wu, H-C

    2016-01-01

    Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835

  20. Helical relativistic electron beam Vlasov equilibria

    NASA Astrophysics Data System (ADS)

    Lai, H. M.

    1980-08-01

    Three existing helical relativistic electron beam models are discussed and compared. Both Yoshikawa's and Lawson's models are shown to be derivable from appropriate Vlasov equilibria. A new helical Vlasov equilibrium with energy spread is presented and studied. Unlike Auer's axial current model in which the allowance of an energy spread limits the total current in the relativistic beam case, the present model, with the addition of an azimuthal current, permits solutions with arbitrarily large current. On the other hand, like the model studied by Kan and Lai, the present model leads to nonhollowed-out beam solutions in which, the larger the beam current, the more force-free is the magnetic field configuration.

  1. General Relativistic and Newtonian White Dwarfs

    NASA Astrophysics Data System (ADS)

    Boshkayev, K.; Rueda, J. A.; Ruffini, R.; Siutsou, I.

    2015-01-01

    The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of Newton's gravity and general relativity. In both cases Hartle's formalism is applied to construct the internal and external solutions to the field equations. The white dwarf (WD) matter is described by the Chandrasekhar equation of state. The region of stability of RWDs is constructed taking into account the mass-shedding limit, inverse β-decay instability, and the boundary established by the turning points of constant angular momentum J sequences which separates stable from secularly unstable configurations. We found the minimum rotation period ˜ 0.28 s in both cases and maximum rotating masses ˜ 1.534M⊙ and ˜ 1.516M⊙ for the Newtonian and general relativistic WDs, respectively. By using the turning point method we show that general relativistic WDs can indeed be axisymmetrically unstable whereas the Newtonian WDs are stable.

  2. Relativistic Bohmian Mechanics Without a Preferred Foliation

    NASA Astrophysics Data System (ADS)

    Galvan, Bruno

    2015-12-01

    In non-relativistic Bohmian mechanics the universe is represented by a probability space whose sample space is composed of the Bohmian trajectories. In relativistic Bohmian mechanics an entire class of empirically equivalent probability spaces can be defined, one for every foliation of spacetime. In the literature the hypothesis has been advanced that a single preferred foliation is allowed, and that this foliation derives from the universal wave function by means of a covariant law. In the present paper the opposite hypothesis is advanced, i.e., no law exists for the foliations and therefore all the foliations are allowed. The resulting model of the universe is basically the "union" of all the probability spaces associated with the foliations. This hypothesis is mainly motivated by the fact that any law defining a preferred foliation is empirically irrelevant. It is also argued that the absence of a preferred foliation may reduce the well known conflict between Bohmian mechanics and relativity.

  3. Double relativistic electron-accelerating mirror

    SciTech Connect

    Andreev, Aleksandr A; Platonov, Konstantin Yu

    2013-05-31

    A numerical simulation of the interaction of a laser pulse with ultrathin targets has revealed a possibility of generating thin dense relativistic electron layers. The maximum kinetic energy of the electron mirror can be gained using an optimal combination of the target thickness and the laser pulse intensity and duration. It is proposed to use an additional (second) laser target, located at an optimal distance from the first target to cut off the laser pulse from the electron layer when the latter gains a maximum kinetic energy. This relativistic electron mirror can be used for efficient generation of 'hard' coherent radiation via counter reflection of an additional (probe) laser pulse from the mirror. (interaction of laser radiation with matter. laser plasma)

  4. Graphical evaluation of relativistic matrix elements

    NASA Technical Reports Server (NTRS)

    Huang, K. N.

    1978-01-01

    A graphical representation of angular momentum was used to evaluate relativistic matrix elements between antisymmetrized states of many particle configurations having any number of open shells. The antisymmetrized matrix element was expanded as a sum of semisymmetrized matrix elements. The diagram representing a semisymmetrized matrix element was composed of four diagram blocks; the bra block, the ket block, the spectator block, and the interaction block. The first three blocks indicate the couplings of the two interacting configurations while the last depends on the interaction and is the replaceable component. Interaction blocks for relativistic operators and commonly used potentials were summarized in ready to use forms. A simple step by step procedure was prescribed generally for calculating antisymmetrized matrix elements of one and two particle operators.

  5. Distinct optical properties of relativistically degenerate matter

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2014-06-01

    In this paper, we use the collisional quantum magnetohydrodynamic (CQMHD) model to derive the transverse dielectric function of a relativistically degenerate electron fluid and investigate various optical parameters, such as the complex refractive index, the reflection and absorption coefficients, the skin-depth and optical conductivity. In this model we take into accounts effects of many parameters such as the atomic-number of the constituent ions, the electron exchange, electron diffraction effect and the electron-ion collisions. Study of the optical parameters in the solid-density, the warm-dense-matter, the big-planetary core, and the compact star number-density regimes reveals that there are distinct differences between optical characteristics of the latter and the former cases due to the fundamental effects of the relativistic degeneracy and other quantum mechanisms. It is found that in the relativistic degeneracy plasma regime, such as found in white-dwarfs and neutron star crusts, matter possess a much sharper and well-defined step-like reflection edge beyond the x-ray electromagnetic spectrum, including some part of gamma-ray frequencies. It is also remarked that the magnetic field intensity only significantly affects the plasma reflectivity in the lower number-density regime, rather than the high density limit. Current investigation confirms the profound effect of relativistic degeneracy on optical characteristics of matter and can provide an important plasma diagnostic tool for studying the physical processes within the wide scope of quantum plasma regimes be it the solid-density, inertial-confined, or astrophysical compact stars.

  6. Spectral Methods in General Relativistic MHD Simulations

    NASA Astrophysics Data System (ADS)

    Garrison, David

    2012-03-01

    In this talk I discuss the use of spectral methods in improving the accuracy of a General Relativistic Magnetohydrodynamic (GRMHD) computer code. I introduce SpecCosmo, a GRMHD code developed as a Cactus arrangement at UHCL, and show simulation results using both Fourier spectral methods and finite differencing. This work demonstrates the use of spectral methods with the FFTW 3.3 Fast Fourier Transform package integrated with the Cactus Framework to perform spectral differencing using MPI.

  7. Relativistic point interactions: Approximation by smooth potentials

    NASA Astrophysics Data System (ADS)

    Hughes, Rhonda J.

    1997-06-01

    We show that the four-parameter family of one-dimensional relativistic point interactions studied by Benvegnu and Dąbrowski may be approximated in the strong resolvent sense by smooth, local, short-range perturbations of the Dirac Hamiltonian. In addition, we prove that the nonrelativistic limits correspond to the Schrödinger point interactions studied extensively by the author and Paul Chernoff.

  8. Relativistic diffusive motion in thermal electromagnetic fields

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2013-04-01

    We discuss relativistic dynamics in a random electromagnetic field which can be considered as a high temperature limit of the quantum electromagnetic field in a heat bath (cavity) moving with a uniform velocity w. We derive a diffusion approximation for the particle’s dynamics generalizing the diffusion of Schay and Dudley. It is shown that the Jüttner distribution is the equilibrium state of the diffusion.

  9. Light exotic systems at relativistic velocities

    NASA Astrophysics Data System (ADS)

    Simon, H.

    2010-03-01

    In this paper the results of a series of experiments, carried out at the GSI accelerator facilities in Darmstadt at the Aladin-LAND reaction setup are presented. Light nuclei at relativistic velocities, impinging on a carbon and a liquid hydrogen reaction target break up and all fragments are detected in coincidence. The observed correlations are used to draw conclusions on the underlying structure of the bound exotic projectiles as well as to explore continuum structures.

  10. Relativistic timescale analysis suggests lunar theory revision

    NASA Astrophysics Data System (ADS)

    Deines, Steven D.; Williams, Carol A.

    1995-05-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  11. Femtoscopy in Relativistic Heavy Ion Collisions

    SciTech Connect

    Lisa, M; Pratt, S; Soltz, R A; Wiedemann, U

    2005-07-29

    Analyses of two-particle correlations have provided the chief means for determining spatio-temporal characteristics of relativistic heavy ion collisions. We discuss the theoretical formalism behind these studies and the experimental methods used in carrying them out. Recent results from RHIC are put into context in a systematic review of correlation measurements performed over the past two decades. The current understanding of these results are discussed in terms of model comparisons and overall trends.

  12. On particle acceleration in astrophysical relativistic jets

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail

    2015-11-01

    Relativistic jets, e.g., in active galactic nuclei, are believed to be accelerators of high-energy cosmic rays. This is a lore but no justification of it exists. We investigate this problem from the first principles and present arguments that ``no-jets'' are better accelerators than the jets themselves. Supported by grant DOE grant DE-FG02-07ER54940 and NSF grant AST-1209665.

  13. Relativistic timescale analysis suggests lunar theory revision

    NASA Technical Reports Server (NTRS)

    Deines, Steven D.; Williams, Carol A.

    1995-01-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  14. Distinct optical properties of relativistically degenerate matter

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2014-06-15

    In this paper, we use the collisional quantum magnetohydrodynamic (CQMHD) model to derive the transverse dielectric function of a relativistically degenerate electron fluid and investigate various optical parameters, such as the complex refractive index, the reflection and absorption coefficients, the skin-depth and optical conductivity. In this model we take into accounts effects of many parameters such as the atomic-number of the constituent ions, the electron exchange, electron diffraction effect and the electron-ion collisions. Study of the optical parameters in the solid-density, the warm-dense-matter, the big-planetary core, and the compact star number-density regimes reveals that there are distinct differences between optical characteristics of the latter and the former cases due to the fundamental effects of the relativistic degeneracy and other quantum mechanisms. It is found that in the relativistic degeneracy plasma regime, such as found in white-dwarfs and neutron star crusts, matter possess a much sharper and well-defined step-like reflection edge beyond the x-ray electromagnetic spectrum, including some part of gamma-ray frequencies. It is also remarked that the magnetic field intensity only significantly affects the plasma reflectivity in the lower number-density regime, rather than the high density limit. Current investigation confirms the profound effect of relativistic degeneracy on optical characteristics of matter and can provide an important plasma diagnostic tool for studying the physical processes within the wide scope of quantum plasma regimes be it the solid-density, inertial-confined, or astrophysical compact stars.

  15. Relativistic Electron Transport Through Carbon Foils

    NASA Astrophysics Data System (ADS)

    Seliger, M.; Takasi, K.; Reinhold, C. O.; Takabayashi, Y.; Ito, T.; Komaki, K.; Azuma, T.; Yamazaki, Y.; Yamazaki, Y.

    We present a theoretical study of convoy electron emission resulting from transmission of relativistic 390 MeV/amu Ar17+ ions through carbon foils of various thicknesses. Our approach is based on a Langevin equation describing the random walk of the electron initially bound to the argon nucleus and later in the continuum. The calculated spectra of ejected electrons in the forward direction exhibit clear signatures of multiple scattering and are found to be in good agreement with recent experimental data.

  16. Relativistic thermodynamics with an invariant energy scale

    SciTech Connect

    Das, Sudipta; Ghosh, Subir; Roychowdhury, Dibakar

    2009-12-15

    A particular framework for quantum gravity is the doubly special relativity (DSR) formalism that introduces a new observer independent scale, the Planck energy. Our aim in this paper is to study the effects of this energy upper bound in relativistic thermodynamics. We have explicitly computed the modified equation of state for an ideal fluid in the DSR framework. In deriving our result we exploited the scheme of treating DSR as a nonlinear representation of the Lorentz group in special relativity.

  17. Exact relativistic {beta} decay endpoint spectrum

    SciTech Connect

    Masood, S. S.; Nasri, S.; Schechter, J.; Tortola, M. A.; Valle, J. W. F.

    2007-10-15

    The exact relativistic form for the {beta} decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN Collaboration. We also discuss the three-neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future {beta} decay endpoint experiments.

  18. Renormalization group for non-relativistic fermions.

    PubMed

    Shankar, R

    2011-07-13

    A brief introduction is given to the renormalization group for non-relativistic fermions at finite density. It is shown that Landau's theory of the Fermi liquid arises as a fixed point (with the Landau parameters as marginal couplings) and its instabilities as relevant perturbations. Applications to related areas, nuclear matter, quark matter and quantum dots, are briefly discussed. The focus will be on explaining the main ideas to people in related fields, rather than addressing the experts. PMID:21646269

  19. Diffusion processes in general relativistic radiating spheres

    SciTech Connect

    Barreto, W.; Herrera, L.; Santos, N.O.; Universidad Central de Venezuela, Caracas; Observatorio Nacional do Brasil, Rio de Janeiro )

    1989-09-01

    The influence of diffusion processes on the dynamics of general relativistic radiating spheres is systematically studied by means of two examples. Differences between the streaming-out limit and the diffusion limit are exhibited, for both models, through the evolution curves of dynamical variables. In particular it is shown the Bondi mass decreases, for both models, in the diffusion limit as compared with its value at the streaming-out regime. 15 refs.

  20. Jets in relativistic heavy ion collisions

    SciTech Connect

    Wang, Xin-Nian; Gyulassy, M.

    1990-09-01

    Several aspects of hard and semihard QCD jets in relativistic heavy ion collisions are discussed, including multiproduction of minijets and the interaction of a jet with dense nuclear matter. The reduction of jet quenching effect in deconfined phase of nuclear matter is speculated to provide a signature of the formation of quark gluon plasma. HIJING Monte Carlo program which can simulate events of jets production and quenching in heavy ion collisions is briefly described. 35 refs., 13 figs.

  1. Scattering of twisted relativistic electrons by atoms

    NASA Astrophysics Data System (ADS)

    Serbo, V.; Ivanov, I. P.; Fritzsche, S.; Seipt, D.; Surzhykov, A.

    2015-07-01

    The Mott scattering of high-energetic twisted electrons by atoms is investigated within the framework of the first Born approximation and Dirac's relativistic equation. Special emphasis is placed on the angular distribution and longitudinal polarization of the scattered electrons. In order to evaluate these angular and polarization properties we consider two experimental setups in which the twisted electron beam collides with either a single well-localized atom or macroscopic atomic target. Detailed relativistic calculations have been performed for both setups and for the electrons with kinetic energy from 10 to 1000 keV. The results of these calculations indicate that the emission pattern and polarization of outgoing electrons differ significantly from the scattering of plane-wave electrons and can be very sensitive to the parameters of the incident twisted beam. In particular, it is shown that the angular- and polarization-sensitive Mott measurements may reveal valuable information about both the transverse and longitudinal components of the linear momentum and the projection of the total angular momentum of twisted electron states. Thus, the Mott scattering emerges as a diagnostic tool for the relativistic vortex beams.

  2. Relativistically strong electromagnetic radiation in a plasma

    NASA Astrophysics Data System (ADS)

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Kiriyama, H.; Kondo, K.

    2016-03-01

    Physical processes in a plasma under the action of relativistically strong electromagnetic waves generated by high-power lasers have been briefly reviewed. These processes are of interest in view of the development of new methods for acceleration of charged particles, creation of sources of bright hard electromagnetic radiation, and investigation of macroscopic quantum-electrodynamical processes. Attention is focused on nonlinear waves in a laser plasma for the creation of compact electron accelerators. The acceleration of plasma bunches by the radiation pressure of light is the most efficient regime of ion acceleration. Coherent hard electromagnetic radiation in the relativistic plasma is generated in the form of higher harmonics and/or electromagnetic pulses, which are compressed and intensified after reflection from relativistic mirrors created by nonlinear waves. In the limit of extremely strong electromagnetic waves, radiation friction, which accompanies the conversion of radiation from the optical range to the gamma range, fundamentally changes the behavior of the plasma. This process is accompanied by the production of electron-positron pairs, which is described within quantum electrodynamics theory.

  3. A Magnetohydrodynamic Boost for Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Mizuno, Yosuke; Hardee, Philip; Hartmann, Dieter H.; Nishikawa, Ken-Ichi; Zhang, Bing

    2007-01-01

    We performed relativistic magnetohydrodynamic simulations of the hydrodynamic boosting mechanism for relativistic jets explored by Aloy & Rezzolla (2006) using the RAISHIN code. Simulation results show that the presence of a magnetic field changes the properties of the shock interface between the tenuous, overpressured jet (V^z j) flowing tangentially to a dense external medium. We find that magnetic fields can lead to more efficient acceleration of the jet, in comparison to the pure-hydrodynamic case. A "poloidal" magnetic field (B^z), tangent to the interface and parallel to the jet flow, produces both a stronger outward moving shock and a stronger inward moving rarefaction wave. This leads to a large velocity component normal to the interface in addition to acceleration tangent to the interface, and the jet is thus accelerated to larger Lorentz factors than those obtained in the pure-hydrodynamic case. Likewise, a strong "toroidal" magnetic field (B^y), tangent to the interface but perpendicular to the jet flow, also leads to stronger acceleration tangent to the shock interface relative to the pure-hydrodynamic case. Thus. the presence and relative orientation of a magnetic field in relativistic jets can significant modify the hydrodynamic boost mechanism studied by Aloy & Rezzolla (2006).

  4. General relativistic effects in atom interferometry

    SciTech Connect

    Dimopoulos, Savas; Hogan, Jason M.; Kasevich, Mark A.; Graham, Peter W.

    2008-08-15

    Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the nonrelativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this, we develop a method for calculating the phase shift in general relativity. Both the atoms and the light are treated relativistically and all coordinate dependencies are removed, thus revealing novel terms, cancellations, and new origins for previously calculated terms. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the nonlinear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose specific experiments, one currently under construction, to measure each of these effects. These experiments could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the Universe, and preferred frame and location effects.

  5. Plasma heating with crossing relativistic electron beams

    NASA Astrophysics Data System (ADS)

    Ratan, Naren; Sircombe, Nathan; Ceurvorst, Luke; Kasim, Muhammad; Sadler, James; Bingham, Robert; Trines, Raoul; Norreys, Peter

    2015-11-01

    Plasma heating by relativistic electron beams is a powerful tool with applications including the heating of inertial confinement fusion targets and the study of matter in extreme conditions. We discuss the use of two relativistic electron beams to efficiently heat the plasma ions where the beams cross by using beam-plasma instabilities and non-linear wave coupling between Langmuir and ion-acoustic waves. Energy from the electron beams is coupled to the plasma ions as the beams become unstable and drive Langmuir waves which couple non-linearly to ion-acoustic waves which are then damped . Results of linear growth rate calculations are presented for the system of two crossing electron beams demonstrating a broad spectrum of unstable modes. Relativistic Vlasov-Maxwell simulations in two space and two momentum dimensions have been performed which demonstrate the non-linear coupling of the electron beam energy into ion-acoustic waves and the energy cascade to the background ions. Time-frequency analysis is applied to analyze the non-linear coupling between Langmuir and ion-acoustic waves in wave phase space. Structural properties of the strong turbulence produced at late times are analyzed.

  6. Special relativistic visualization by local ray tracing.

    PubMed

    Müller, Thomas; Grottel, Sebastian; Weiskopf, Daniel

    2010-01-01

    Special relativistic visualization offers the possibility of experiencing the optical effects of traveling near the speed of light, including apparent geometric distortions as well as Doppler and searchlight effects. Early high-quality computer graphics images of relativistic scenes were created using offline, computationally expensive CPU-side 4D ray tracing. Alternate approaches such as image-based rendering and polygon-distortion methods are able to achieve interactivity, but exhibit inferior visual quality due to sampling artifacts. In this paper, we introduce a hybrid rendering technique based on polygon distortion and local ray tracing that facilitates interactive high-quality visualization of multiple objects moving at relativistic speeds in arbitrary directions. The method starts by calculating tight image-space footprints for the apparent triangles of the 3D scene objects. The final image is generated using a single image-space ray tracing step incorporating Doppler and searchlight effects. Our implementation uses GPU shader programming and hardware texture filtering to achieve high rendering speed. PMID:20975164

  7. Cosmological measurements with general relativistic galaxy correlations

    NASA Astrophysics Data System (ADS)

    Raccanelli, Alvise; Montanari, Francesco; Bertacca, Daniele; Doré, Olivier; Durrer, Ruth

    2016-05-01

    We investigate the cosmological dependence and the constraining power of large-scale galaxy correlations, including all redshift-distortions, wide-angle, lensing and gravitational potential effects on linear scales. We analyze the cosmological information present in the lensing convergence and in the gravitational potential terms describing the so-called ``relativistic effects'', and we find that, while smaller than the information contained in intrinsic galaxy clustering, it is not negligible. We investigate how neglecting them does bias cosmological measurements performed by future spectroscopic and photometric large-scale surveys such as SKA and Euclid. We perform a Fisher analysis using the CLASS code, modified to include scale-dependent galaxy bias and redshift-dependent magnification and evolution bias. Our results show that neglecting relativistic terms, especially lensing convergence, introduces an error in the forecasted precision in measuring cosmological parameters of the order of a few tens of percent, in particular when measuring the matter content of the Universe and primordial non-Gaussianity parameters. The analysis suggests a possible substantial systematic error in cosmological parameter constraints. Therefore, we argue that radial correlations and integrated relativistic terms need to be taken into account when forecasting the constraining power of future large-scale number counts of galaxy surveys.

  8. Localization and Entanglement in Relativistic Quantum Physics

    NASA Astrophysics Data System (ADS)

    Yngvason, Jakob

    These notes are a slightly expanded version of a lecture presented in February 2012 at the workshop "The Message of Quantum Science—Attempts Towards a Synthesis" held at the ZIF in Bielefeld. The participants were physicists with a wide range of different expertise and interests. The lecture was intended as a survey of a small selection of the insights into the structure of relativistic quantum physics that have accumulated through the efforts of many people over more than 50 years. (Including, among many others, R. Haag, H. Araki, D. Kastler, H.-J. Borchers, A. Wightman, R. Streater, B. Schroer, H. Reeh, S. Schlieder, S. Doplicher, J. Roberts, R. Jost, K. Hepp, J. Fröhlich, J. Glimm, A. Jaffe, J. Bisognano, E. Wichmann, D. Buchholz, K. Fredenhagen, R. Longo, D. Guido, R. Brunetti, J. Mund, S. Summers, R. Werner, H. Narnhofer, R. Verch, G. Lechner, ….) This contribution discusses some facts about relativistic quantum physics, most of which are quite familiar to practitioners of Algebraic Quantum Field Theory (AQFT) [Also known as Local Quantum Physics (Haag, Local quantum physics. Springer, Berlin, 1992).] but less well known outside this community. No claim of originality is made; the goal of this contribution is merely to present these facts in a simple and concise manner, focusing on the following issues: Explaining how quantum mechanics (QM) combined with (special) relativity, in particular an upper bound on the propagation velocity of effects, leads naturally to systems with an infinite number of degrees of freedom (relativistic quantum fields).

  9. TOPICAL REVIEW: Relativistic laser-plasma interactions

    NASA Astrophysics Data System (ADS)

    Umstadter, Donald

    2003-04-01

    By focusing petawatt peak power laser light to intensities up to 1021 W cm-2, highly relativistic plasmas can now be studied. The force exerted by light pulses with this extreme intensity has been used to accelerate beams of electrons and protons to energies of a million volts in distances of only microns. This acceleration gradient is a thousand times greater than in radio-frequency-based accelerators. Such novel compact laser-based radiation sources have been demonstrated to have parameters that are useful for research in medicine, physics and engineering. They might also someday be used to ignite controlled thermonuclear fusion. Ultrashort pulse duration particles and x-rays that are produced can resolve chemical, biological or physical reactions on ultrafast (femtosecond) timescales and on atomic spatial scales. These energetic beams have produced an array of nuclear reactions, resulting in neutrons, positrons and radioactive isotopes. As laser intensities increase further and laser-accelerated protons become relativistic, exotic plasmas, such as dense electron-positron plasmas, which are of astrophysical interest, can be created in the laboratory. This paper reviews many of the recent advances in relativistic laser-plasma interactions.

  10. General Relativistic Effects in Atom Interferometry

    SciTech Connect

    Dimopoulos, Savas; Graham, Peter W.; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.

    2008-03-17

    Atom interferometry is now reaching sufficient precision to motivate laboratory tests of general relativity. We begin by explaining the non-relativistic calculation of the phase shift in an atom interferometer and deriving its range of validity. From this we develop a method for calculating the phase shift in general relativity. This formalism is then used to find the relativistic effects in an atom interferometer in a weak gravitational field for application to laboratory tests of general relativity. The potentially testable relativistic effects include the non-linear three-graviton coupling, the gravity of kinetic energy, and the falling of light. We propose experiments, one currently under construction, that could provide a test of the principle of equivalence to 1 part in 10{sup 15} (300 times better than the present limit), and general relativity at the 10% level, with many potential future improvements. We also consider applications to other metrics including the Lense-Thirring effect, the expansion of the universe, and preferred frame and location effects.

  11. Test of Relativistic Kinetic Energy Equation

    NASA Astrophysics Data System (ADS)

    Chaudhary, Bharat

    2014-03-01

    Kinetic energy of a body equals the work done on it by a force, constant or variable. Force is the time rate of change of momentum. Momentum is mass times velocity. According to special relativity mass and velocity both are variables. Therefore, the differentiation of their product (momentum) has two terms, both are variables. One term is the product of mass and acceleration. The other is of velocity and the rate of change of mass. They together equal the applied force. Since the force equals the sum of two variable terms, it also becomes a variable even if it was a constant earlier. Therefore it is a flaw. There are two more flaws in the force equation. They are found by putting the force equal to zero. When this is done, the acceleration doesn't become zero. This is physically incompatible and is therefore a flaw. The other flaw in the equation is found by integrating the right side terms and evaluating the constant of integration from the initial conditions. Then we get a term containing logarithm of zero that is undefined, therefore the expression so obtained is meaningless. Since it comes from the relativistic definition of force, therefore we conclude that this definition is wrong. Thus we find that there are three flaws in the relativistic definition of force. They all make the relativistic equation of force wrong.

  12. Hydrodynamic approaches in relativistic heavy ion reactions

    NASA Astrophysics Data System (ADS)

    Derradi de Souza, R.; Koide, T.; Kodama, T.

    2016-01-01

    We review several facets of the hydrodynamic description of the relativistic heavy ion collisions, starting from the historical motivation to the present understandings of the observed collective aspects of experimental data, especially those of the most recent RHIC and LHC results. In this report, we particularly focus on the conceptual questions and the physical foundations of the validity of the hydrodynamic approach itself. We also discuss recent efforts to clarify some of the points in this direction, such as the various forms of derivations of relativistic hydrodynamics together with the limitations intrinsic to the traditional approaches, variational approaches, known analytic solutions for special cases, and several new theoretical developments. Throughout this review, we stress the role of course-graining procedure in the hydrodynamic description and discuss its relation to the physical observables through the analysis of a hydrodynamic mapping of a microscopic transport model. Several questions to be answered to clarify the physics of collective phenomena in the relativistic heavy ion collisions are pointed out.

  13. Ultra-Relativistic Heavy Ion Nuclear Physics

    SciTech Connect

    Braithwaite, W. J.

    1995-05-31

    This report describes an on-going research initiative for the University of Arkansas at Little Rock (UALR): investigating the physics of ultra-relativistic heavy ions, i.e. collisions between massive nuclei which have been accelerated to kinetic energies so large that the rest mass of the ions is a negligible fraction of their total mass-energy. This progress report is being submitted in conjunction with a 3-year grant-renewal proposal, containing additional materials. Three main categories drive the UALRGultra-relativistic heavy ion research. (1) investigations of multi-particle Hanbury-Brown-Twiss (HBT) correlations in the CERN and RHIC energy domains strongly influence the URHI experimental effort, (2) participation in the NA49 Experiment to study 33 TeV (160 GeV/nucleon) Pb on Pb collisions using the SPS facili& at CERN, and (3) participation in the STAR collaboration which is developing a major detector for use with the STAR Experiment at the Relativistic Heavy Ion Collider (RHIC), being built at BNL.

  14. Relativistic Shocks: Particle Acceleration and Magnetization

    NASA Astrophysics Data System (ADS)

    Sironi, L.; Keshet, U.; Lemoine, M.

    2015-10-01

    We review the physics of relativistic shocks, which are often invoked as the sources of non-thermal particles in pulsar wind nebulae (PWNe), gamma-ray bursts (GRBs), and active galactic nuclei (AGN) jets, and as possible sources of ultra-high energy cosmic-rays. We focus on particle acceleration and magnetic field generation, and describe the recent progress in the field driven by theory advances and by the rapid development of particle-in-cell (PIC) simulations. In weakly magnetized or quasi parallel-shocks (i.e. where the magnetic field is nearly aligned with the flow), particle acceleration is efficient. The accelerated particles stream ahead of the shock, where they generate strong magnetic waves which in turn scatter the particles back and forth across the shock, mediating their acceleration. In contrast, in strongly magnetized quasi-perpendicular shocks, the efficiencies of both particle acceleration and magnetic field generation are suppressed. Particle acceleration, when efficient, modifies the turbulence around the shock on a long time scale, and the accelerated particles have a characteristic energy spectral index of s_{γ}˜eq2.2 in the ultra-relativistic limit. We discuss how this novel understanding of particle acceleration and magnetic field generation in relativistic shocks can be applied to high-energy astrophysical phenomena, with an emphasis on PWNe and GRB afterglows.

  15. Secondary antiproton production in relativistic plasmas

    NASA Technical Reports Server (NTRS)

    Dermer, C. D.; Ramaty, R.

    1985-01-01

    The possibility is investigated that the reported excess low energy antiproton component of the cosmic radiation results from proton-proton (p-p) interactions in relativistic plasmas. Because of both target and projectile motion in such plasmas, the antiproton production threshold in the frame of the plasma is much lower than the threshold of antiproton production in cosmic ray interactions with ambient matter. The spectrum of the resultant antiprotons therefore extends to much lower energy than in the cosmic ray case. The antiproton spectrum is calculated for relativistic thermal plasmas and the spectrum is estimated for relativistic nonthermal plasmas. As possible production sites, matter accreting onto compact objects located in the galaxy is considered. Possible overproduction of gamma rays from associated neutral pion production can be avoided if the site is optically thick to the photons but not to the antiprotons. A possible scenario involves a sufficiently large photon density that the neutral pion gamma rays are absorbed by photon-photon pair production. Escape of the antiprotons to the interstellar medium can be mediated by antineutron production.

  16. Magnetogenesis through a Relativistic Biermann Effect

    NASA Astrophysics Data System (ADS)

    Miller, Evan

    2012-10-01

    In a 2010 Physical Review Letter, Mahajan and Yoshida proposed a relativistic correction to the well-known Biermann Battery. The Biermann Battery allows for the generation of magnetic fields in a plasma fluid from orthogonal gradients in temperature and entropy (Bt ∇T x∇σ). The proposed correction would result in an additional term, proportional to the gradient of velocity squared crossed with the gradient of entropy (Bt ∇v^2 x∇σ). This new effect can in some cases provide the dominate source of magnetic field growth, even when the fluid is only mildly relativistic. This could in turn help explain the dynamics of certain relativistic plasmas, including modern laser plasmas and astrophysical jets. It is possible it could even provide a primordial source for the seed fields needed to explain the cosmological magnetic fields that appear to permeate most galaxies. In my poster, I will explain the theory underlying this new correction and present simulations demonstrating magnetic field growth in a variety of test cases, performed using both a particle-in-cell code and a fluid model.

  17. Volume-preserving algorithm for secular relativistic dynamics of charged particles

    SciTech Connect

    Zhang, Ruili; Liu, Jian; Wang, Yulei; He, Yang; Qin, Hong; Sun, Yajuan

    2015-04-15

    Secular dynamics of relativistic charged particles has theoretical significance and a wide range of applications. However, conventional algorithms are not applicable to this problem due to the coherent accumulation of numerical errors. To overcome this difficulty, we develop a volume-preserving algorithm (VPA) with long-term accuracy and conservativeness via a systematic splitting method. Applied to the simulation of runaway electrons with a time-span over 10 magnitudes, the VPA generates accurate results and enables the discovery of new physics for secular runaway dynamics.

  18. Applying an accurate spherical model to gamma-ray burst afterglow observations

    NASA Astrophysics Data System (ADS)

    Leventis, K.; van der Horst, A. J.; van Eerten, H. J.; Wijers, R. A. M. J.

    2013-05-01

    We present results of model fits to afterglow data sets of GRB 970508, GRB 980703 and GRB 070125, characterized by long and broad-band coverage. The model assumes synchrotron radiation (including self-absorption) from a spherical adiabatic blast wave and consists of analytic flux prescriptions based on numerical results. For the first time it combines the accuracy of hydrodynamic simulations through different stages of the outflow dynamics with the flexibility of simple heuristic formulas. The prescriptions are especially geared towards accurate description of the dynamical transition of the outflow from relativistic to Newtonian velocities in an arbitrary power-law density environment. We show that the spherical model can accurately describe the data only in the case of GRB 970508, for which we find a circumburst medium density n ∝ r-2. We investigate in detail the implied spectra and physical parameters of that burst. For the microphysics we show evidence for equipartition between the fraction of energy density carried by relativistic electrons and magnetic field. We also find that for the blast wave to be adiabatic, the fraction of electrons accelerated at the shock has to be smaller than 1. We present best-fitting parameters for the afterglows of all three bursts, including uncertainties in the parameters of GRB 970508, and compare the inferred values to those obtained by different authors.

  19. Global relativistic folding optical potential and the relativistic Green's function model

    NASA Astrophysics Data System (ADS)

    Ivanov, M. V.; Vignote, J. R.; Álvarez-Rodríguez, R.; Meucci, A.; Giusti, C.; Udías, J. M.

    2016-07-01

    Optical potentials provide critical input for calculations on a wide variety of nuclear reactions, in particular, for neutrino-nucleus reactions, which are of great interest in the light of the new neutrino oscillation experiments. We present the global relativistic folding optical potential (GRFOP) fits to elastic proton scattering data from 12C nucleus at energies between 20 and 1040 MeV. We estimate observables, such as the differential cross section, the analyzing power, and the spin rotation parameter, in elastic proton scattering within the relativistic impulse approximation. The new GRFOP potential is employed within the relativistic Green's function model for inclusive quasielastic electron scattering and for (anti)neutrino-nucleus scattering at MiniBooNE kinematics.

  20. Application of Central Upwind Scheme for Solving Special Relativistic Hydrodynamic Equations.

    PubMed

    Yousaf, Muhammad; Ghaffar, Tayabia; Qamar, Shamsul

    2015-01-01

    The accurate modeling of various features in high energy astrophysical scenarios requires the solution of the Einstein equations together with those of special relativistic hydrodynamics (SRHD). Such models are more complicated than the non-relativistic ones due to the nonlinear relations between the conserved and state variables. A high-resolution shock-capturing central upwind scheme is implemented to solve the given set of equations. The proposed technique uses the precise information of local propagation speeds to avoid the excessive numerical diffusion. The second order accuracy of the scheme is obtained with the use of MUSCL-type initial reconstruction and Runge-Kutta time stepping method. After a discussion of the equations solved and of the techniques employed, a series of one and two-dimensional test problems are carried out. To validate the method and assess its accuracy, the staggered central and the kinetic flux-vector splitting schemes are also applied to the same model. The scheme is robust and efficient. Its results are comparable to those obtained from the sophisticated algorithms, even in the case of highly relativistic two-dimensional test problems. PMID:26070067

  1. General relativistic monopole magnetosphere of neutron stars: a pseudo-spectral discontinuous Galerkin approach

    NASA Astrophysics Data System (ADS)

    Pétri, J.

    2015-03-01

    The close vicinity of neutron stars remains poorly constrained by observations. Although plenty of data are available for the peculiar class of pulsars we are still unable to deduce the underlying plasma distribution in their magnetosphere. In the present paper, we try to unravel the magnetospheric structure starting from basic physics principles and reasonable assumptions about the magnetosphere. Beginning with the monopole force-free case, we compute accurate general relativistic solutions for the electromagnetic field around a slowly rotating magnetized neutron star. Moreover, here we address this problem by including the important effect of plasma screening. This is achieved by solving the time-dependent Maxwell equations in a curved space-time following the 3+1 formalism. We improved our previous numerical code based on pseudo-spectral methods in order to allow for possible discontinuities in the solution. Our algorithm based on a multidomain decomposition of the simulation box belongs to the discontinuous Galerkin finite element methods. We performed several sets of simulations to look for the general relativistic force-free monopole and split monopole solutions. Results show that our code is extremely powerful in handling extended domains of hundredth of light cylinder radii rL. The code has been validated against known exact analytical monopole solutions in flat space-time. We also present semi-analytical calculations for the general relativistic vacuum monopole.

  2. Contribution of relativistic quantum chemistry to electron's electric dipole moment for CP violation

    NASA Astrophysics Data System (ADS)

    Abe, M.; Gopakumar, G.; Das, B. P.; Tatewaki, H.; Mukherjee, D.; Hada, M.

    2015-12-01

    The search for the electric dipole moment of the electron (eEDM) is important because it is a probe of Charge Conjugation-Parity (CP) violation. It can also shed light on new physics beyond the standard model. It is not possible to measure the eEDM directly. However, the interaction energy involving the effective electric field (Eeff) acting on an electron in a molecule and the eEDM can be measured. This quantity can be combined with Eeff, which is calculated by relativistic molecular orbital theory to determine eEDM. Previous calculations of Eeff were not sufficiently accurate in the treatment of relativistic or electron correlation effects. We therefore developed a new method to calculate Eeff based on a four-component relativistic coupled-cluster theory. We demonstrated our method for YbF molecule, one of the promising candidates for the eEDM search. Using very large basis set and without freezing any core orbitals, we obtain a value of 23.1 GV/cm for Eeff in YbF with an estimated error of less than 10%. The error is assessed by comparison of our calculations and experiments for two properties relevant for Eeff, permanent dipole moment and hyperfine coupling constant. Our method paves the way to calculate properties of various kinds of molecules which can be described by a single-reference wave function.

  3. Relativistic nuclear recoil, electron correlation and QED effects in highly charged Ar ions

    NASA Astrophysics Data System (ADS)

    Harman, Z.; Soria Orts, R.; Lapierre, A.; Crespo Lopez-Urrutia, J. R.; Artemyev, A. N.; Tupitsyn, I. I.; Jentschura, U. D.; Keitel, C. H.; Tawara, H.; Ullrich, J.; Shabaev, V. M.; Volotka, A. V.

    2007-06-01

    We have performed extensive theoretical studies on the 1s^22s^22p^2P3/2 -- ^2P1/2 M1 transition in Ar^13+ ions. Accurate radiative lifetimes are sensitive to QED corrections like the electron anomalous magnetic moment and to relativistic electron correlation effects. The lifetime of the P3/2 metastable state was determined to be 9.573(4)(5) ms (stat)(syst) [1] using the Heidelberg electron beam ion trap. Theoretical predictions cluster around a value that is significantly shorter than this high-precision experimental result. This discrepancy is presently unexplained. The wavelengths of the above transition in Ar^13+ and the 1s^22s2p ^3P1 -- ^3P2 M1 transition in Ar^14+ were compared for the isotopes ^36Ar and ^40Ar [2]. The observed mass shift has confirmed the relativistic theory of nuclear recoil effects in many-body systems. Our calculations, based on the fully relativistic recoil operator, are in excellent agreement with the measured results. [1] A. Lapierre, U.D. Jentschura, J.R. Crespo L'opez-Urrutia et al., Phys. Rev. Lett. 95, 183001 (2005); [2] R. Soria Orts, Z. Harman, J.R. Crespo L'opez-Urrutia et al., Phys. Rev. Lett. 97, 103002 (2006)

  4. Application of Central Upwind Scheme for Solving Special Relativistic Hydrodynamic Equations

    PubMed Central

    Yousaf, Muhammad; Ghaffar, Tayabia; Qamar, Shamsul

    2015-01-01

    The accurate modeling of various features in high energy astrophysical scenarios requires the solution of the Einstein equations together with those of special relativistic hydrodynamics (SRHD). Such models are more complicated than the non-relativistic ones due to the nonlinear relations between the conserved and state variables. A high-resolution shock-capturing central upwind scheme is implemented to solve the given set of equations. The proposed technique uses the precise information of local propagation speeds to avoid the excessive numerical diffusion. The second order accuracy of the scheme is obtained with the use of MUSCL-type initial reconstruction and Runge-Kutta time stepping method. After a discussion of the equations solved and of the techniques employed, a series of one and two-dimensional test problems are carried out. To validate the method and assess its accuracy, the staggered central and the kinetic flux-vector splitting schemes are also applied to the same model. The scheme is robust and efficient. Its results are comparable to those obtained from the sophisticated algorithms, even in the case of highly relativistic two-dimensional test problems. PMID:26070067

  5. The space-time CE/SE method for solving ultra-relativistic Euler equations

    NASA Astrophysics Data System (ADS)

    Qamar, Shamsul; Yousaf, Muhammad; Mudasser, Sidrah

    2011-04-01

    This paper reports the application of space-time conservation element and solution element (CE/SE) method for solving one- and two-dimensional special ultra-relativistic Euler equations. For a sufficiently large internal energy of fluid particles the rest-mass energy of the fluid can be ignored. Then, the fluid flow can be modeled by ultra-relativistic Euler equations consisting a pair of coupled first-order non-linear hyperbolic partial differential equations. The governing equations describe the flow of a perfect fluid in terms of the particle density ρ, the spatial part of the four-velocity u and the pressure p. The CE/SE method is capable to accurately captures the sharp propagating wavefront of relativistic fluid without excessive numerical diffusion or spurious oscillations. In contrast to the existing upwind finite volume schemes, the Riemann solver and reconstruction procedure are not the building block of the suggested method. The method differs from the previous techniques because of global and local flux conservation in a space-time domain without resorting to interpolation or extrapolation. In order to reveal the efficiency and performance of the approach, several numerical test cases are presented in this manuscript. For validation, the results of current method are compared with other finite-volume schemes.

  6. Contribution of relativistic quantum chemistry to electron’s electric dipole moment for CP violation

    SciTech Connect

    Abe, M. Gopakumar, G. Hada, M.; Das, B. P.; Tatewaki, H.; Mukherjee, D.

    2015-12-31

    The search for the electric dipole moment of the electron (eEDM) is important because it is a probe of Charge Conjugation-Parity (CP) violation. It can also shed light on new physics beyond the standard model. It is not possible to measure the eEDM directly. However, the interaction energy involving the effective electric field (E{sub eff}) acting on an electron in a molecule and the eEDM can be measured. This quantity can be combined with E{sub eff}, which is calculated by relativistic molecular orbital theory to determine eEDM. Previous calculations of E{sub eff} were not sufficiently accurate in the treatment of relativistic or electron correlation effects. We therefore developed a new method to calculate E{sub eff} based on a four-component relativistic coupled-cluster theory. We demonstrated our method for YbF molecule, one of the promising candidates for the eEDM search. Using very large basis set and without freezing any core orbitals, we obtain a value of 23.1 GV/cm for E{sub eff} in YbF with an estimated error of less than 10%. The error is assessed by comparison of our calculations and experiments for two properties relevant for E{sub eff}, permanent dipole moment and hyperfine coupling constant. Our method paves the way to calculate properties of various kinds of molecules which can be described by a single-reference wave function.

  7. Relativistic effects on the bonding and properties of the hydrides of platinum

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.

    1993-01-01

    The ground state of PtH2 and several low-lying states of PtH(+) and PtH have been studied at the all-electron self-consistent-field level of theory to examine the importance of relativistic effects. The results of calculations based on Dirac-Hartree-Fock theory, nonrelativistic theory, and the spin-free no-pair relativistic approximation of Hess are compared to separate the effects of the spin-free terms and the spin-orbit terms of the Hamiltonian on the relativistic corrections to the molecular properties. Comparison is also made between first-order perturbation theory including the one-electron spin-free terms and the method of Hess to determine the size of effects beyond first order. It is found that the spin-orbit interaction significantly affects the properties and energetics of these molecules because of the participation of the Pt 5d orbitals in the bonding, and that effects beyond first order in perturbation theory are large. Any treatment of Pt compounds will have to include both the spin-free and spin-orbit interactions for an accurate description.

  8. HERO - A 3D general relativistic radiative post-processor for accretion discs around black holes

    NASA Astrophysics Data System (ADS)

    Zhu, Yucong; Narayan, Ramesh; Sadowski, Aleksander; Psaltis, Dimitrios

    2015-08-01

    HERO (Hybrid Evaluator for Radiative Objects) is a 3D general relativistic radiative transfer code which has been tailored to the problem of analysing radiation from simulations of relativistic accretion discs around black holes. HERO is designed to be used as a post-processor. Given some fixed fluid structure for the disc (i.e. density and velocity as a function of position from a hydrodynamic or magnetohydrodynamic simulation), the code obtains a self-consistent solution for the radiation field and for the gas temperatures using the condition of radiative equilibrium. The novel aspect of HERO is that it combines two techniques: (1) a short-characteristics (SC) solver that quickly converges to a self-consistent disc temperature and radiation field, with (2) a long-characteristics (LC) solver that provides a more accurate solution for the radiation near the photosphere and in the optically thin regions. By combining these two techniques, we gain both the computational speed of SC and the high accuracy of LC. We present tests of HERO on a range of 1D, 2D, and 3D problems in flat space and show that the results agree well with both analytical and benchmark solutions. We also test the ability of the code to handle relativistic problems in curved space. Finally, we discuss the important topic of ray defects, a major limitation of the SC method, and describe our strategy for minimizing the induced error.

  9. Why criteria for impulse approximation in Compton scattering fail in relativistic regimes

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2014-05-01

    The assumption behind impulse approximation (IA) for Compton scattering is that the momentum transfer q is much greater than the average < p > of the initial bound state momentum distribution p. Comparing with S-matrix results, we find that at relativistic incident photon energies (ωi) and for high Z elements, one requires information beyond < p > / q to predict the accuracy of relativistic IA (RIA) diferential cross sections. The IA expression is proportional to the product of a kinematic factor Xnr and the symmetrical Compton profile J, where Xnr = 1 + cos2 θ (θ is the photon scattering angle). In the RIA case, Xnr, independent of p, is replaced by Xrel (ω , θ , p) in the integrand which determines J. At nr energies there is virtually no RIA error in the position of the Compton peak maximum (ωfpk) in the scattered photon energy (ωf), while RIA error in the peak magnitude can be characterized by < p > / q . This is because at low ωi, the kinematic effects described by S-matrix (also RIA) expressions behave like Xnr, while in relativistic regimes (high ωi and Z), kinematic factors treated accurately by S-matrix but not RIA expressions become significant and do not factor out.

  10. Formulation of the relativistic quantum Hall effect and parity anomaly

    NASA Astrophysics Data System (ADS)

    Yonaga, Kouki; Hasebe, Kazuki; Shibata, Naokazu

    2016-06-01

    We present a relativistic formulation of the quantum Hall effect on Haldane sphere. An explicit form of the pseudopotential is derived for the relativistic quantum Hall effect with/without mass term. We clarify particular features of the relativistic quantum Hall states with the use of the exact diagonalization study of the pseudopotential Hamiltonian. Physical effects of the mass term to the relativistic quantum Hall states are investigated in detail. The mass term acts as an interpolating parameter between the relativistic and nonrelativistic quantum Hall effects. It is pointed out that the mass term unevenly affects the many-body physics of the positive and negative Landau levels as a manifestation of the "parity anomaly." In particular, we explicitly demonstrate the instability of the Laughlin state of the positive first relativistic Landau level with the reduction of the charge gap.

  11. Global Solutions to the Ultra-Relativistic Euler Equations

    NASA Astrophysics Data System (ADS)

    Wissman, B. D.

    2011-09-01

    We show that when entropy variations are included and special relativity is imposed, the thermodynamics of a perfect fluid leads to two distinct families of equations of state whose relativistic compressible Euler equations are of Nishida type. (In the non-relativistic case there is only one.) The first corresponds exactly to the Stefan-Boltzmann radiation law, and the other, emerges most naturally in the ultra-relativistic limit of a γ-law gas, the limit in which the temperature is very high or the rest mass very small. We clarify how these two relativistic equations of state emerge physically, and provide a unified analysis of entropy variations to prove global existence in one space dimension for the two distinct 3 × 3 relativistic Nishida-type systems. In particular, as far as we know, this provides the first large data global existence result for a relativistic perfect fluid constrained by the Stefan-Boltzmann radiation law.

  12. Exact Relativistic Newtonian Representation of Gravitational static Spacetime Geometries

    NASA Astrophysics Data System (ADS)

    Ghosh, Shubhrangshu; Sarkar, Tamal; Bhadra, Arunava

    2016-09-01

    We construct a self-consistent relativistic Newtonian analogue corresponding to gravitational static spherical symmetric spacetime geometries, starting directly from a generalized scalar relativistic gravitational action in a Newtonian framework, which gives geodesic equations of motion identical to those of the parent metric. Consequently, the derived velocity-dependent relativistic scalar potential, which is a relativistic generalization of the Newtonian gravitational potential, exactly reproduces the relativistic gravitational features corresponding to any static spherical symmetric spacetime geometry in its entirety, including all the experimentally tested gravitational effects in the weak field up to the present. This relativistic analogous potential is expected to be quite useful in studying a wide range of astrophysical phenomena, especially in strong field gravity.

  13. Role of the Kelvin-Helmholtz instability in the evolution of magnetized relativistic sheared plasma flows

    NASA Astrophysics Data System (ADS)

    Hamlin, Nathaniel D.; Newman, William I.

    2013-04-01

    We explore, via analytical and numerical methods, the Kelvin-Helmholtz (KH) instability in relativistic magnetized plasmas, with applications to astrophysical jets. We solve the single-fluid relativistic magnetohydrodynamic (RMHD) equations in conservative form using a scheme which is fourth order in space and time. To recover the primitive RMHD variables, we use a highly accurate, rapidly convergent algorithm which improves upon such schemes as the Newton-Raphson method. Although the exact RMHD equations are marginally stable, numerical discretization renders them unstable. We include numerical viscosity to restore numerical stability. In relativistic flows, diffusion can lead to a mathematical anomaly associated with frame transformations. However, in our KH studies, we remain in the rest frame of the system, and therefore do not encounter this anomaly. We use a two-dimensional slab geometry with periodic boundary conditions in both directions. The initial unperturbed velocity peaks along the central axis and vanishes asymptotically at the transverse boundaries. Remaining unperturbed quantities are uniform, with a flow-aligned unperturbed magnetic field. The early evolution in the nonlinear regime corresponds to the formation of counter-rotating vortices, connected by filaments, which persist in the absence of a magnetic field. A magnetic field inhibits the vortices through a series of stages, namely, field amplification, vortex disruption, turbulent breakdown, and an approach to a flow-aligned equilibrium configuration. Similar stages have been discussed in MHD literature. We examine how and to what extent these stages manifest in RMHD for a set of representative field strengths. To characterize field strength, we define a relativistic extension of the Alfvénic Mach number MA. We observe close complementarity between flow and magnetic field behavior. Weaker fields exhibit more vortex rotation, magnetic reconnection, jet broadening, and intermediate turbulence

  14. Relativistic Corrections to the Properties of the Alkali Fluorides

    NASA Technical Reports Server (NTRS)

    Dyall, Kenneth G.; Partridge, Harry

    1993-01-01

    Relativistic corrections to the bond lengths, dissociation energies and harmonic frequencies of KF, RbF and CsF have been obtained at the self-consistent field level by dissociating to ions. The relativistic corrections to the bond lengths, harmonic frequencies and dissociation energies to the ions are very small, due to the ionic nature of these molecules and the similarity of the relativistic and nonrelativistic ionic radii.

  15. Mill profiler machines soft materials accurately

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1966-01-01

    Mill profiler machines bevels, slots, and grooves in soft materials, such as styrofoam phenolic-filled cores, to any desired thickness. A single operator can accurately control cutting depths in contour or straight line work.

  16. Remote balance weighs accurately amid high radiation

    NASA Technical Reports Server (NTRS)

    Eggenberger, D. N.; Shuck, A. B.

    1969-01-01

    Commercial beam-type balance, modified and outfitted with electronic controls and digital readout, can be remotely controlled for use in high radiation environments. This allows accurate weighing of breeder-reactor fuel pieces when they are radioactively hot.

  17. Maximum mass, moment of inertia and compactness of relativistic stars

    NASA Astrophysics Data System (ADS)

    Breu, Cosima; Rezzolla, Luciano

    2016-06-01

    A number of recent works have highlighted that it is possible to express the properties of general-relativistic stellar equilibrium configurations in terms of functions that do not depend on the specific equation of state employed to describe matter at nuclear densities. These functions are normally referred to as `universal relations' and have been found to apply, within limits, both to static or stationary isolated stars, as well as to fully dynamical and merging binary systems. Further extending the idea that universal relations can be valid also away from stability, we show that a universal relation is exhibited also by equilibrium solutions that are not stable. In particular, the mass of rotating configurations on the turning-point line shows a universal behaviour when expressed in terms of the normalized Keplerian angular momentum. In turn, this allows us to compute the maximum mass allowed by uniform rotation, Mmax, simply in terms of the maximum mass of the non-rotating configuration, M_{_TOV}, finding that M_max ≃ (1.203 ± 0.022) M_{_TOV} for all the equations of state we have considered. We further introduce an improvement to previously published universal relations by Lattimer & Schutz between the dimensionless moment of inertia and the stellar compactness, which could provide an accurate tool to constrain the equation of state of nuclear matter when measurements of the moment of inertia become available.

  18. Approaches to relativistic positioning around Earth and error estimations

    NASA Astrophysics Data System (ADS)

    Puchades, Neus; Sáez, Diego

    2016-01-01

    In the context of relativistic positioning, the coordinates of a given user may be calculated by using suitable information broadcast by a 4-tuple of satellites. Our 4-tuples belong to the Galileo constellation. Recently, we estimated the positioning errors due to uncertainties in the satellite world lines (U-errors). A distribution of U-errors was obtained, at various times, in a set of points covering a large region surrounding Earth. Here, the positioning errors associated to the simplifying assumption that photons move in Minkowski space-time (S-errors) are estimated and compared with the U-errors. Both errors have been calculated for the same points and times to make comparisons possible. For a certain realistic modeling of the world line uncertainties, the estimated S-errors have proved to be smaller than the U-errors, which shows that the approach based on the assumption that the Earth's gravitational field produces negligible effects on photons may be used in a large region surrounding Earth. The applicability of this approach - which simplifies numerical calculations - to positioning problems, and the usefulness of our S-error maps, are pointed out. A better approach, based on the assumption that photons move in the Schwarzschild space-time governed by an idealized Earth, is also analyzed. More accurate descriptions of photon propagation involving non symmetric space-time structures are not necessary for ordinary positioning and spacecraft navigation around Earth.

  19. Relativistic MHD simulations of stellar core collapse and magnetars

    NASA Astrophysics Data System (ADS)

    Font, José A.; Cerdá-Durán, Pablo; Gabler, Michael; Müller, Ewald; Stergioulas, Nikolaos

    2011-02-01

    We present results from simulations of magneto-rotational stellar core collapse along with Alfvén oscillations in magnetars. These simulations are performed with the CoCoA/CoCoNuT code, which is able to handle ideal MHD flows in dynamical spacetimes in general relativity. Our core collapse simulations highlight the importance of genuine magnetic effects, like the magneto-rotational instability, for the dynamics of the flow. For the modelling of magnetars we use the anelastic approximation to general relativistic MHD, which allows for an effective suppression of fluid modes and an accurate description of Alfvén waves. We further compute Alfvén oscillation frequencies along individual magnetic field lines with a semi-analytic approach. Our work confirms previous results based on perturbative approaches regarding the existence of two families of quasi-periodic oscillations (QPOs), with harmonics at integer multiples of the fundamental frequency. Additional material is presented in the accompanying contribution by Gabler et al (2010b) in these proceedings.

  20. Relativistic nonlinear plasma waves in a magnetic field

    NASA Technical Reports Server (NTRS)

    Kennel, C. F.; Pellat, R.

    1975-01-01

    Five relativistic plane nonlinear waves were investigated: circularly polarized waves and electrostatic plasma oscillations propagating parallel to the magnetic field, relativistic Alfven waves, linearly polarized transverse waves propagating in zero magnetic field, and the relativistic analog of the extraordinary mode propagating at an arbitrary angle to the magnetic field. When the ions are driven relativistic, they behave like electrons, and the assumption of an 'electron-positron' plasma leads to equations which have the form of a one-dimensional potential well. The solutions indicate that a large-amplitude superluminous wave determines the average plasma properties.

  1. Relativistic blast waves in two dimensions. I - The adiabatic case

    NASA Technical Reports Server (NTRS)

    Shapiro, P. R.

    1979-01-01

    Approximate solutions are presented for the dynamical evolution of strong adiabatic relativistic blast waves which result from a point explosion in an ambient gas in which the density varies both with distance from the explosion center and with polar angle in axisymmetry. Solutions are analytical or quasi-analytical for the extreme relativistic case and numerical for the arbitrarily relativistic case. Some general properties of nonplanar relativistic shocks are also discussed, including the incoherence of spherical ultrarelativistic blast-wave fronts on angular scales greater than the reciprocal of the shock Lorentz factor, as well as the conditions for producing blast-wave acceleration.

  2. Theoretical study of the relativistic molecular rotational g-tensor

    SciTech Connect

    Aucar, I. Agustín Gomez, Sergio S.; Giribet, Claudia G.; Ruiz de Azúa, Martín C.

    2014-11-21

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH{sup +} (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH{sup +} systems. Only for the sixth-row Rn atom a significant deviation of this relation is found.

  3. Theoretical study of the relativistic molecular rotational g-tensor.

    PubMed

    Aucar, I Agustín; Gomez, Sergio S; Giribet, Claudia G; Ruiz de Azúa, Martín C

    2014-11-21

    An original formulation of the relativistic molecular rotational g-tensor valid for heavy atom containing compounds is presented. In such formulation, the relevant terms of a molecular Hamiltonian for non-relativistic nuclei and relativistic electrons in the laboratory system are considered. Terms linear and bilinear in the nuclear rotation angular momentum and an external uniform magnetic field are considered within first and second order (relativistic) perturbation theory to obtain the rotational g-tensor. Relativistic effects are further analyzed by carrying out the linear response within the elimination of the small component expansion. Quantitative results for model systems HX (X=F, Cl, Br, I), XF (X=Cl, Br, I), and YH(+) (Y=Ne, Ar, Kr, Xe, Rn) are obtained both at the RPA and density functional theory levels of approximation. Relativistic effects are shown to be small for this molecular property. The relation between the rotational g-tensor and susceptibility tensor which is valid in the non-relativistic theory does not hold within the relativistic framework, and differences between both molecular parameters are analyzed for the model systems under study. It is found that the non-relativistic relation remains valid within 2% even for the heavy HI, IF, and XeH(+) systems. Only for the sixth-row Rn atom a significant deviation of this relation is found. PMID:25416870

  4. Very accurate variational non-relativistic non-Born-Oppenheimer atomic & molecular spectra predictions employing explicitly correlated Gaussian basis functions

    NASA Astrophysics Data System (ADS)

    Sharkey, Keeper

    2015-03-01

    Due to the fast increasing capabilities of modern computers it now becomes feasible to calculate spectra of small atom and molecules with accuracy which matches the accuracy of high-resolution measurements. The algorithms for the calculations are directly derived from the first principles of quantum mechanics. The Hamiltonian operator used in the approach is called the internal Hamiltonian and is obtained by rigorously separating out the center-of-mass motion from the laboratory-frame Hamiltonian. Algorithms for determining the isotopic energy shifts of L=0 and M=0 states of atoms were implemented and tested in the calculations of the ground 4S state of the nitrogen atom. Bound states of diatomic molecules corresponding to the total angular momentum quantum number equal to one (N=1) was derived and implemented and was tested in the calculations of the N=1, v=0, . . . , 22 states of the HD+ ion and in the calculations of the ortho-para spin isomerization of the hydrogen molecule in its all bound vibrational states. This has lead to the development of a new studying of muonic molecules (dp μ, tp μ and td μ). The algorithms for calculating rovibrational states of small molecules is currently being extended to H3+using sin and cos ECGs. National Science Foundation.

  5. Understanding the Code: keeping accurate records.

    PubMed

    Griffith, Richard

    2015-10-01

    In his continuing series looking at the legal and professional implications of the Nursing and Midwifery Council's revised Code of Conduct, Richard Griffith discusses the elements of accurate record keeping under Standard 10 of the Code. This article considers the importance of accurate record keeping for the safety of patients and protection of district nurses. The legal implications of records are explained along with how district nurses should write records to ensure these legal requirements are met. PMID:26418404

  6. Exact solutions of regular approximate relativistic wave equations for hydrogen-like atoms

    NASA Astrophysics Data System (ADS)

    van Leeuwen, R.; van Lenthe, E.; Baerends, E. J.; Snijders, J. G.

    1994-07-01

    Apart from relativistic effects originating from high kinetic energy of an electron in a flat potential, which are treated in first order by the Pauli Hamiltonian, there are relativistic effects even for low-energy electrons if they move in a strong Coulomb potential. The latter effects can be accurately treated already in the zeroth order of an expansion of the Foldy-Wouthuysen transformation, if the expansion is carefully chosen to be nondivergent for r→0 even for Coulomb potentials, as shown by Van Lenthe et al. [J. Chem. Phys. 99, 4597 (1993)] (cf. also Heully et al. [J. Phys. B 19, 2799 (1986)] and Chang et al. [Phys. Scr. 34, 394 (1986)]). In the present paper, it is shown that the solutions of the zeroth order of this two-component regular approximate (ZORA) equation for hydrogen-like atoms are simply scaled solutions of the large component of the Dirac wave function for this problem. The eigenvalues are related in a similar way. As a consequence, it is proven that under some restrictions, the ZORA Hamiltonian is bounded from below for Coulomb-like potentials. Also, an exact result for the first order regular approximate Hamiltonian is given. The method can also be used to obtain exact results for regular approximations of scalar relativistic equations, like the Klein-Gordon equation. The balance between relativistic effects originating from the Coulombic singularity in the potential (typically core penetrating s and p valence electrons in atoms and molecules) and from high kinetic energy (important for high-energy electrons in a flat potential and also for core-avoiding high angular momentum (d, f, and g states in atoms) are discussed.

  7. Darwin and mass-velocity relativistic corrections in the non-Born-Oppenheimer calculations of pure vibrational states of H2.

    PubMed

    Kedziera, Dariusz; Stanke, Monika; Bubin, Sergiy; Barysz, Maria; Adamowicz, Ludwik

    2006-07-01

    The Darwin and mass-velocity relativistic corrections have been calculated for all pure vibrational states of the H2 using the perturbation theory and very accurate variational wave functions obtained without assuming the Born-Oppenheimer (BO) approximation. Expansions in terms of explicitly correlated Gaussians with premultipliers in the form of even powers of the internuclear distance were used for the wave functions. With the inclusion of the two relativistic corrections to the non-BO energies the transition energies for the highest states agree more with the experimental results. PMID:16863309

  8. Electromagnetic energy density manipulation and enhancement in a relativistic plasma: the role of relativistic nonlinearities

    SciTech Connect

    Pegoraro, F.

    2009-11-10

    A tutorial presentation is given describing the nature and the effects of relativistic nonlinearities in a plasma and indicating how they can be exploited in order to manipulate and enhance locally the energy density of the electromagnetic fields. The mathematical formulation and the examples presented are chosen from results available in the scientific literature.

  9. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    SciTech Connect

    Schollmeier, M.; Sefkow, A. B.; Geissel, M.; Kimmel, M. W.; Rambo, P. K.; Schwarz, J.; Arefiev, A. V.; Flippo, K. A.; Johnson, R. P.; Shimada, T.; Gaillard, S. A.; Offermann, D. T.

    2015-04-15

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results show that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.

  10. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    SciTech Connect

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; Schwarz, Jens; Shimada, Tom

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.

  11. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    DOE PAGESBeta

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; et al

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge ofmore » the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.« less

  12. Interplanetary Magnetic Field Guiding Relativistic Particles

    NASA Technical Reports Server (NTRS)

    Masson, S.; Demoulin, P.; Dasso, S.; Klein, K. L.

    2011-01-01

    The origin and the propagation of relativistic solar particles (0.5 to few Ge V) in the interplanetary medium remains a debated topic. These relativistic particles, detected at the Earth by neutron monitors have been previously accelerated close to the Sun and are guided by the interplanetary magnetic field (IMF) lines, connecting the acceleration site and the Earth. Usually, the nominal Parker spiral is considered for ensuring the magnetic connection to the Earth. However, in most GLEs the IMF is highly disturbed, and the active regions associated to the GLEs are not always located close to the solar footprint of the nominal Parker spiral. A possible explanation is that relativistic particles are propagating in transient magnetic structures, such as Interplanetary Coronal Mass Ejections (ICMEs). In order to check this interpretation, we studied in detail the interplanetary medium where the particles propagate for 10 GLEs of the last solar cycle. Using the magnetic field and the plasma parameter measurements (ACE/MAG and ACE/SWEPAM), we found widely different IMF configurations. In an independent approach we develop and apply an improved method of the velocity dispersion analysis to energetic protons measured by SoHO/ERNE. We determined the effective path length and the solar release time of protons from these data and also combined them with the neutron monitor data. We found that in most of the GLEs, protons propagate in transient magnetic structures. Moreover, the comparison between the interplanetary magnetic structure and the interplanetary length suggest that the timing of particle arrival at Earth is dominantly determined by the type of IMF in which high energetic particles are propagating. Finally we find that these energetic protons are not significantly scattered during their transport to Earth.

  13. A Magnetohydrodynamic Boost for Relativistic Jets

    NASA Technical Reports Server (NTRS)

    Mizuno, Yosuke; Hardee, Philip; Hartmann, dieter; Nishikwa, Ken-Ichi; Zhang, Bing

    2006-01-01

    We have performed relativistic magnetohydrodynamic simulations of the hydrodynamic boosting mechanism for relativistic jets explored by Aloy & Rezzolla (2006) using the RAISHIN code. Simulation results show that the presence of a magnetic field may change the properties of the shock interface between the tenuous, overpressured jet (V(sub j) (sup z)) flowing tangentially to a dense external medium. Magnetic fields can lead to more efficient acceleration of the jet, in comparison to the pure-hydrodynamic case. A poloidal magnetic field (B(sup z)), tangent to the interface and parallel to the jet flow, produces both a stronger outward moving shock and inward moving rarefaction wave. This leads to a large velocity component normal to the interface in addition to acceleration tangent to the interface, and the jet is thus accelerated to a larger Lorentz factors than those obtained in the pure-hydrodynamic case. In contrast, a strong toroidal magnetic field (B(sup y)), tangent to the interface but perpendicular to the jet flow, also leads to stronger acceleration tangent to the shock interface relative to the pure-hydrodynamic case, but to a lesser extent than found for the poloidal case due to the fact that the velocity component normal to the shock interface is now much smaller. Overall, the acceleration efficiency in the toroidal case is less than that of the poloidal case but both geometries still result in higher Lorentz factors than the pure-hydrodynamic case. Thus, the presence and relative orientation of a magnetic field in relativistic jets can have a significant influence on the hydrodynamic boost mechanism studied by Aloy & Rezzolla (2006).

  14. String Mechanism for Relativistic Jet Formation

    NASA Astrophysics Data System (ADS)

    Dyadechkin, S. A.; Semenov, V. S.; Punsly, B.; Biernat, H. K.

    Here we present our latest studies of relativistic jet formation in the vicinity of a rotating black hole where the reconnection process has been taken into account. In order to simplify the problem, we use Lagrangian formalism and develop a method which enables us to consider a magnetized plasma as a set of magnetic flux tubes [5,6]. Within the limits of the Lagrangian approach, we perform numerical simulations of the flux tube (nonlinear string) behavior which clearly demonstrates the process of relativistic jet formation in the form of outgoing torsional nonlinear aves. It turns out that the jet is produced deep inside the ergosphere where the flux tube takes away spinning energy from the black hole due to the nonlocal Penrose process [2]. This is similar to the Blandford-Znajek (BZ) mechanism to some extent [8], however, the string mechanism is essentially time dependent. It is shown that the leading part of the accreting tube gains negative energy and therefore has to stay in the ergosphere forever. Simultaneously, another part of the tube propagates along the spinning axis away from the hole with nearly the speed of light. As a result, the tube is continuously stretching and our mechanism is essentially time dependent. Obviously, such process cannot last infinitely long and we have to take into account the reconnection process. Due to reconnection, the topology of the flux tube is changed and it gives rise to a plasmoid creation which propagates along spin axis of the hole with relativistic speed carrying off the energy and angular momentum away from the black hole.

  15. Numerical relativistic hydrodynamic simulations of neutron stars

    NASA Astrophysics Data System (ADS)

    Haywood, Joe R.

    Developments in numerical relativistic hydrodynamics over the past thirty years, along with the advent of high speed computers, have made problems needing general relativity and relativistic hydrodynamics tractable. One such problem is the relativistic evolution of neutron stars, either in a head on collision or in binary orbit. Also of current interest is the detection of gravitational radiation from binary neutron stars, black-hole neutron star binaries, binary black holes, etc. Such systems expected to emit gravitational radiation with amplitude large enough to be detected on Earth by such groups as LIGO and VIRGO. Unfortunately, the expected signal strength is below the current noise level. However, signal processing techniques have been developed which should eventually find a signal, if a good theoretical template can be found. In the cases above it is not possible to obtain an analytic solution to the Einstein equations and a numerical approximation is therefore most necessary. In this thesis the Einstein equations are written using the formalism of Arnowitt, Desser and Misner and a conformally flat metric is assumed. Numerical simulations of colliding neutron stars, having either a realistic or Gamma = 2 polytropic equation of state (EOS), are presented which confirm the rise in central density seen by [51, 89] for the softer EOS. For the binary calculation, the results of Wilson et al. [89] are confirmed, which show that the neutron stars can collapse to black holes before colliding when the EOS is realistic and we also confirm results of Miller [56] and others that there is essentially no compression, the central density does not increase, when the stiffer equation of state is used. Finally, a template for the gravitational radiation emitted from the binary is calculated and we show that the frequency of the emitted gravitational waves changes more slowly for the [89] EOS, which may result in a stronger signal in the 50-100 Hz band of LIGO.

  16. Inverse Compton Scattering in Mildly Relativistic Plasma

    NASA Technical Reports Server (NTRS)

    Molnar, S. M.; Birkinshaw, M.

    1998-01-01

    We investigated the effect of inverse Compton scattering in mildly relativistic static and moving plasmas with low optical depth using Monte Carlo simulations, and calculated the Sunyaev-Zel'dovich effect in the cosmic background radiation. Our semi-analytic method is based on a separation of photon diffusion in frequency and real space. We use Monte Carlo simulation to derive the intensity and frequency of the scattered photons for a monochromatic incoming radiation. The outgoing spectrum is determined by integrating over the spectrum of the incoming radiation using the intensity to determine the correct weight. This method makes it possible to study the emerging radiation as a function of frequency and direction. As a first application we have studied the effects of finite optical depth and gas infall on the Sunyaev-Zel'dovich effect (not possible with the extended Kompaneets equation) and discuss the parameter range in which the Boltzmann equation and its expansions can be used. For high temperature clusters (k(sub B)T(sub e) greater than or approximately equal to 15 keV) relativistic corrections based on a fifth order expansion of the extended Kompaneets equation seriously underestimate the Sunyaev-Zel'dovich effect at high frequencies. The contribution from plasma infall is less important for reasonable velocities. We give a convenient analytical expression for the dependence of the cross-over frequency on temperature, optical depth, and gas infall speed. Optical depth effects are often more important than relativistic corrections, and should be taken into account for high-precision work, but are smaller than the typical kinematic effect from cluster radial velocities.

  17. Relativistic Lagrangian displacement field and tensor perturbations

    NASA Astrophysics Data System (ADS)

    Rampf, Cornelius; Wiegand, Alexander

    2014-12-01

    We investigate the purely spatial Lagrangian coordinate transformation from the Lagrangian to the basic Eulerian frame. We demonstrate three techniques for extracting the relativistic displacement field from a given solution in the Lagrangian frame. These techniques are (a) from defining a local set of Eulerian coordinates embedded into the Lagrangian frame; (b) from performing a specific gauge transformation; and (c) from a fully nonperturbative approach based on the Arnowitt-Deser-Misner (ADM) split. The latter approach shows that this decomposition is not tied to a specific perturbative formulation for the solution of the Einstein equations. Rather, it can be defined at the level of the nonperturbative coordinate change from the Lagrangian to the Eulerian description. Studying such different techniques is useful because it allows us to compare and develop further the various approximation techniques available in the Lagrangian formulation. We find that one has to solve the gravitational wave equation in the relativistic analysis, otherwise the corresponding Newtonian limit will necessarily contain spurious nonpropagating tensor artifacts at second order in the Eulerian frame. We also derive the magnetic part of the Weyl tensor in the Lagrangian frame, and find that it is not only excited by gravitational waves but also by tensor perturbations which are induced through the nonlinear frame dragging. We apply our findings to calculate for the first time the relativistic displacement field, up to second order, for a Λ CDM Universe in the presence of a local primordial non-Gaussian component. Finally, we also comment on recent claims about whether mass conservation in the Lagrangian frame is violated.

  18. DECELERATING RELATIVISTIC TWO-COMPONENT JETS

    SciTech Connect

    Meliani, Z.; Keppens, R. E-mail: Rony.Keppens@wis.kuleuven.b

    2009-11-10

    Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low-density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer jet components then have a different origin and launching mechanism, making their effective inertia, magnetization, associated energy flux, and angular momentum content different as well. Their interface will develop differential rotation, where disruptions may occur. Here we investigate the stability of rotating, two-component relativistic outflows typical for jets in radio galaxies. For this purpose, we parametrically explore the long-term evolution of a transverse cross section of radially stratified jets numerically, extending our previous study where a single, purely hydrodynamic evolution was considered. We include cases with poloidally magnetized jet components, covering hydro and magnetohydrodynamic (MHD) models. With grid-adaptive relativistic MHD simulations, augmented with approximate linear stability analysis, we revisit the interaction between the two jet components. We study the influence of dynamically important poloidal magnetic fields, with varying contributions of the inner component jet to the total kinetic energy flux of the jet, on their non-linear azimuthal stability. We demonstrate that two-component jets with high kinetic energy flux and inner jet effective inertia which is higher than the outer jet effective inertia are subject to the development of a relativistically enhanced, rotation-induced Rayleigh-Taylor-type instability. This instability plays a major role in decelerating the inner jet and the overall jet decollimation. This novel deceleration scenario can partly explain the radio source dichotomy, relating it directly to the efficiency of the central engine in launching the inner jet component. The FRII/FRI transition could then occur when the relative kinetic energy flux of the

  19. Braking formula for electrons of relativistic speed

    NASA Astrophysics Data System (ADS)

    Bethe, H.

    2014-11-01

    From the theory of Møller [Møller, Chr. 1931. Über den Stoß zweier Teilchen unter Berücksichtigung der Retardation der Kräfte. Zeitschrift f. Phys. 70: 786-795] the energy loss of electrons with relativistic speeds passing through matter is derived. The energy loss per centimeter of distance reaches a minimum at about 96% of the speed of light and increases again at higher speeds; for electrons of several billion Volt it is about 4 million Volt per centimeter of water. A table of the theoretical energy loss for electrons and protons of various speeds is given.

  20. Relativistic Mean Field description of exotic nuclei

    NASA Astrophysics Data System (ADS)

    Gambhir, Y. K.

    1994-03-01

    The Relativistic Mean Field (RMF) approach which essentially is an extension of the original σ — ω model of Walecka, has been applied to exotic nuclei as an illustration. We consider nuclei near Z = 34 in the very interesting 2p-1f region. The calculated binding energies, root mean square radii, deformations and other observables are very satisfactory and are in accordance with the experiment (where available) and also with the available empirical studies. Large deformations and shape co-existence are obtained for several cases.

  1. Optimization of a relativistic quantum mechanical engine

    NASA Astrophysics Data System (ADS)

    Peña, Francisco J.; Ferré, Michel; Orellana, P. A.; Rojas, René G.; Vargas, P.

    2016-08-01

    We present an optimal analysis for a quantum mechanical engine working between two energy baths within the framework of relativistic quantum mechanics, adopting a first-order correction. This quantum mechanical engine, with the direct energy leakage between the energy baths, consists of two adiabatic and two isoenergetic processes and uses a three-level system of two noninteracting fermions as its working substance. Assuming that the potential wall moves at a finite speed, we derive the expression of power output and, in particular, reproduce the expression for the efficiency at maximum power.

  2. Imperfect relativistic mirrors in the quantum regime

    SciTech Connect

    Mendonça, J. T.; Serbeto, A.; Galvão, R. M. O.

    2014-05-15

    The collective backscattering of intense laser radiation by energetic electron beams is considered in the relativistic quantum regime. Exact solutions for the radiation field are obtained, for arbitrary electron pulse shapes and laser intensities. The electron beams act as imperfect nonlinear mirrors on the incident laser radiation. This collective backscattering process can lead to the development of new sources of ultra-short pulse radiation in the gamma-ray domain. Numerical examples show that, for plausible experimental conditions, intense pulses of gamma-rays, due to the double Doppler shift of the harmonics of the incident laser radiation, can be produced using the available technology, with durations less than 1 as.

  3. Dynamical phase trajectories for relativistic nuclear collisions

    SciTech Connect

    Arsene, I. C.; Bravina, L. V.; Cassing, W.; Ivanov, Yu. B.; Russkikh, V. N.; Larionov, A.; Randrup, J.; Toneev, V. D.; Zeeb, G.; Zschiesche, D.

    2007-03-15

    Central collisions of gold nuclei are simulated by several existing models and the central net baryon density {rho} and the energy density {epsilon} are extracted at successive times for beam kinetic energies of 5-40 GeV/nucleon. The resulting trajectories in the ({rho},{epsilon}) phase plane are discussed from the perspective of experimentally exploring the expected first-order hadronization phase transition with the planned FAIR at GSI or in a low-energy campaign at the Relativistic Heavy Ion Collider.

  4. An X-band overmoded relativistic klystron

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Chen, Changhua; Deng, Yuqun; Li, Jiawei; Bai, Xianchen

    2014-11-01

    An X-band overmoded relativistic klystron is proposed, the operation mode of which is the TM02 mode. The drift tube could not cut off the TM01 mode; isolating the buncher cavity from the input cavity is achieved by introducing a sectional RF lossy material. Microwaves are extracted from the modulated electron beam using a cylindrical waveguide, rather than a coaxial waveguide; thereby, the output structure is significantly simplified. Particle-in-cell simulations show that microwaves with power of 1.28 GW and frequency of 9.30 GHz can be obtained, corresponding to an efficiency of 32% and relative bandwidth of about 8%.

  5. Relativistic diffusion of elementary particles with spin

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2009-11-01

    We obtain a generalization of the relativistic diffusion of Schay and Dudley for particles with spin. The diffusion equation is a classical version of an equation for the Wigner function of an elementary particle. The elementary particle is described by a unitary irreducible representation of the Poincare group realized in the Hilbert space of wavefunctions in the momentum space. The arbitrariness of the Wigner rotation appears as a gauge freedom of the diffusion equation. The spin is described by an SU(2) connection of a fiber bundle over the momentum hyperbolic space (the mass shell). Motion in an electromagnetic field, transport equations and equilibrium states are discussed.

  6. Analytic solutions of the relativistic Boltzmann equation

    NASA Astrophysics Data System (ADS)

    Hatta, Yoshitaka; Martinez, Mauricio; Xiao, Bo-Wen

    2015-04-01

    We present new analytic solutions to the relativistic Boltzmann equation within the relaxation time approximation. We first obtain spherically expanding solutions which are the kinetic counterparts of the exact solutions of the Israel-Stewart equation in the literature. This allows us to compare the solutions of the kinetic and hydrodynamic equations at an analytical level. We then derive a novel boost-invariant solution of the Boltzmann equation which has an unconventional dependence on the proper time. The existence of such a solution is also suggested in second-order hydrodynamics and fluid-gravity correspondence.

  7. Space-based Tests of Relativistic Gravitation

    NASA Astrophysics Data System (ADS)

    Turyshev, Vyacheslav G.

    Since its initial publication, Einstein's general theory of relativity had been tested to a very high precision and presently is considered to be the standard theory of gravitation, especially when the phenomena in astrophysics, cosmology, and fundamental physics are concerned. As such, this theory has many practically important applications including spacecraft navigation, relativistic geodesy, time transfer, etc. Here we discuss the foundations of general relativity, present its current empirical status, and highlight the need for the new generation of high-accuracy tests. We present some space-based gravitational experiments and discuss anticipated advances in our understanding of the fundamental laws of nature.

  8. Dynamical friction in a relativistic plasma.

    PubMed

    Pike, O J; Rose, S J

    2014-05-01

    The work of Spitzer on dynamical friction in a plasma [L. Spitzer, Jr., Physics of Fully Ionized Gases, 2nd ed. (Wiley, New York, 1962), Chap. 5] is extended to relativistic systems. We derive the force of dynamical friction, diffusion tensor, and test particle relaxation rates for a Maxwellian background in the same form as Trubnikov [B. A. Trubnikov, in Reviews of Plasma Physics, edited by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 105], enabling high-temperature laboratory and astrophysical plasmas to be modeled in a consistent manner. PMID:25353904

  9. Analytical study of diffusive relativistic shock acceleration.

    PubMed

    Keshet, Uri

    2006-12-01

    Particle acceleration in relativistic shocks is studied analytically in the test-particle, small-angle scattering limit, for an arbitrary velocity-angle diffusion function D. The particle spectral index s is found to be sensitive to D, particularly downstream and at certain angles. The analysis, confirmed numerically, justifies and generalizes previous results for isotropic diffusion. It can be used to test collisionless shock models and to observationally constrain D. For example, strongly forward- or backward-enhanced diffusion downstream is ruled out by gamma-ray burst afterglow observations. PMID:17155790

  10. Minimal relativistic three-particle equations

    SciTech Connect

    Lindesay, J.

    1981-07-01

    A minimal self-consistent set of covariant and unitary three-particle equations is presented. Numerical results are obtained for three-particle bound states, elastic scattering and rearrangement of bound pairs with a third particle, and amplitudes for breakup into states of three free particles. The mathematical form of the three-particle bound state equations is explored; constraints are set upon the range of eigenvalues and number of eigenstates of these one parameter equations. The behavior of the number of eigenstates as the two-body binding energy decreases to zero in a covariant context generalizes results previously obtained non-relativistically by V. Efimov.

  11. Relativistic quantum teleportation with superconducting circuits.

    PubMed

    Friis, N; Lee, A R; Truong, K; Sabín, C; Solano, E; Johansson, G; Fuentes, I

    2013-03-15

    We study the effects of relativistic motion on quantum teleportation and propose a realizable experiment where our results can be tested. We compute bounds on the optimal fidelity of teleportation when one of the observers undergoes nonuniform motion for a finite time. The upper bound to the optimal fidelity is degraded due to the observer's motion. However, we discuss how this degradation can be corrected. These effects are observable for experimental parameters that are within reach of cutting-edge superconducting technology. PMID:25166531

  12. Relativistic electron in curved magnetic fields

    NASA Technical Reports Server (NTRS)

    An, S.

    1985-01-01

    Making use of the perturbation method based on the nonlinear differential equation theory, the author investigates the classical motion of a relativistic electron in a class of curved magnetic fields which may be written as B=B(O,B sub phi, O) in cylindrical coordinates (R. phi, Z). Under general astrophysical conditions the author derives the analytical expressions of the motion orbit, pitch angle, etc., of the electron in their dependence upon parameters characterizing the magnetic field and electron. The effects of non-zero curvature of magnetic field lines on the motion of electrons and applicabilities of these results to astrophysics are also discussed.

  13. Microengineering Laser Plasma Interactions at Relativistic Intensities.

    PubMed

    Jiang, S; Ji, L L; Audesirk, H; George, K M; Snyder, J; Krygier, A; Poole, P; Willis, C; Daskalova, R; Chowdhury, E; Lewis, N S; Schumacher, D W; Pukhov, A; Freeman, R R; Akli, K U

    2016-02-26

    We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on microscales using highly ordered Si microwire arrays. The interaction of a high-contrast short-pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both the total and cutoff energies of the produced electron beam. The self-generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microwires as they acquire relativistic energies via direct laser acceleration. PMID:26967419

  14. Relativistic self-focusing in underdense plasma

    SciTech Connect

    Feit, M.D.; Garrison, J.C.; Komashko, A.; Musher, J.L.; Rubenchik, A.M.; Turistsyn, S.K.

    1997-04-24

    In the present paper, we discuss light self-focusing in underdense (nrelativistic self-focusing including ion dynamics will be presented in second part of the paper. In particular, we will demonstrate the formation of empty, wide channels in underdense plasma in the wake of the laser pulse. we discuss the applicability of our results to real situations and possible consequences for the ``Fast Ignitor`` project.

  15. Relativistic thermal plasmas - Pair processes and equilibria

    NASA Technical Reports Server (NTRS)

    Lightman, A. P.

    1982-01-01

    The work of Bisnovatyi-Kogan, Zel'dovich and Sunyaev (1971) is extended and generalized, through the inclusion of pair-producing photon processes and effects due to the finite size of the plasma, in an investigation of the equilibria of relativistic thermal plasmas which takes into account electron-positron creation and annihilation and photons produced within the plasma. It is shown that the bridge between an effectively thin plasma and an effectively thick plasma occurs in the transrelativistic region, where the dimensionless temperature value is between 0.1 and 1.0 and the temperature remains in this region over a great luminosity range.

  16. News and Views: Challenges of Relativistic Astrophysics

    NASA Astrophysics Data System (ADS)

    Opher, Reuven

    2013-12-01

    I discuss some of the most outstanding challenges in relativistic astrophysics in the subjects of compact objects (black holes and neutron stars), dark sector (dark matter and dark energy), plasma astrophysics (origin of jets, cosmic rays, and magnetic fields), and the primordial universe (physics at the beginning of the Universe). In these four subjects, I discuss 12 of the most important challenges. These challenges give us insight into new physics that can only be studied in the large scale universe. The near-future possibilities, in observations and theory, for addressing these challenges are also discussed.

  17. Eddington capture sphere around luminous relativistic stars

    NASA Astrophysics Data System (ADS)

    Wielgus, Maciek

    2016-02-01

    We discuss the interplay of gravity and radiation in a static, spherically symmetric spacetime. Because of the spacetime curvature, balance between radiation pressure from spherical star and effective force of gravity may be established in a particular distance from the star surface, on so-called Eddington capture sphere. This is in contrast with the Newtonian scenario, for which Eddington luminosity of the radiation assures gravity-radiation balance at any radius. We explore properties of this relativistic equilibrium and the dynamics of test particles under radiation influence in the strong gravity regime.

  18. A barrage of relativistic solar particle events

    SciTech Connect

    Bieber, J.W.; Evenson, P.; Pomerantz, M.A. )

    1990-08-01

    During a four-month period beginning July 25, 1989, the sun released an unprecedented barrage of seven relativistic solar particle events detectable with ground-based instrumentation. These 'ground-level enhancements' are the first to occur in the present sunspot cycle, and they include the largest event observed since 1956. Several events are distinguished by unusual fine structure in their time profiles, and one event exhibits an extraordinary spikelike feature at event onset. This paper briefly discusses the characteristics of the time profiles. 10 refs.

  19. Microengineering Laser Plasma Interactions at Relativistic Intensities

    NASA Astrophysics Data System (ADS)

    Jiang, S.; Ji, L. L.; Audesirk, H.; George, K. M.; Snyder, J.; Krygier, A.; Poole, P.; Willis, C.; Daskalova, R.; Chowdhury, E.; Lewis, N. S.; Schumacher, D. W.; Pukhov, A.; Freeman, R. R.; Akli, K. U.

    2016-02-01

    We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on microscales using highly ordered Si microwire arrays. The interaction of a high-contrast short-pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both the total and cutoff energies of the produced electron beam. The self-generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microwires as they acquire relativistic energies via direct laser acceleration.

  20. Relativistically correct DD and DT neutron spectra

    NASA Astrophysics Data System (ADS)

    Appelbe, B.; Chittenden, J.

    2014-06-01

    We use relativistic kinematics to derive an expression for the energy spectrum of neutrons produced by fusion reactions in deuterium and deuterium-tritium thermal plasmas. The derivation does not require approximations and the obtained expression gives the exact shape of the spectrum. It is shown that the high-energy tail of the neutron spectrum is highly sensitive to the plasma temperature. Simple expressions for the plasma temperature as a function of the neutron spectrum full width at half maximum (FWHM) are given.

  1. A relativistic analysis of clock synchronization

    NASA Technical Reports Server (NTRS)

    Thomas, J. B.

    1974-01-01

    The relativistic conversion between coordinate time and atomic time is reformulated to allow simpler time calculations relating analysis in solar-system barycentric coordinates (using coordinate time) with earth-fixed observations (measuring earth-bound proper time or atomic time.) After an interpretation of terms, this simplified formulation, which has a rate accuracy of about 10 to the minus 15th power, is used to explain the conventions required in the synchronization of a world wide clock network and to analyze two synchronization techniques-portable clocks and radio interferometry. Finally, pertinent experiment tests of relativity are briefly discussed in terms of the reformulated time conversion.

  2. The fully relativistic implementation of the convergent close-coupling method

    NASA Astrophysics Data System (ADS)

    Bostock, Christopher James

    2011-04-01

    The calculation of accurate excitation and ionization cross sections for electron collisions with atoms and ions plays a fundamental role in atomic and molecular physics, laser physics, x-ray spectroscopy, plasma physics and chemistry. Within the veil of plasma physics lie important research areas affiliated with the lighting industry, nuclear fusion and astrophysics. For high energy projectiles or targets with a large atomic number it is presently understood that a scattering formalism based on the Dirac equation is required to incorporate relativistic effects. This tutorial outlines the development of the relativistic convergent close-coupling (RCCC) method and highlights the following three main accomplishments. (i) The inclusion of the Breit interaction, a relativistic correction to the Coulomb potential, in the RCCC method. This led to calculations that resolved a discrepancy between theory and experiment for the polarization of x-rays emitted by highly charged hydrogen-like ions excited by electron impact (Bostock et al 2009 Phys. Rev. A 80 052708). (ii) The extension of the RCCC method to accommodate two-electron and quasi-two-electron targets. The method was applied to electron scattering from mercury. Accurate plasma physics modelling of mercury-based fluorescent lamps requires detailed information on a large number of electron impact excitation cross sections involving transitions between various states (Bostock et al 2010 Phys. Rev. A 82 022713). (iii) The third accomplishment outlined in this tutorial is the restructuring of the RCCC computer code to utilize a hybrid OpenMP-MPI parallelization scheme which now enables the RCCC code to run on the latest high performance supercomputer architectures.

  3. Relativistic atomic data for Rb-like tungsten

    NASA Astrophysics Data System (ADS)

    Safronova, U. I.; Safronova, A. S.; Beiersdorfer, P.

    2016-05-01

    Accurate calculations of the atomic properties of Rb-like W37+ are needed for studying high energy density plasma as well as for magnetic fusion applications. In this work, we have calculated energy levels, radiative transition probabilities, and autoionization rates for [Ni] 4s2 4p6 nl , [Ni] 4s2 4p5 4l' nl (l' = d , f , n = 4-7), [Ni] 4 s 4p6 4l' nl ,(l' = d , f , n =4-7), [Ni] 4s2 4p5 5l' nl (n = 5-7), and [Ni] 4 s 4p6 46l' nl (n =6-7) states in Rb-like tungsten (W37+) using the relativistic many-body perturbation theory and the Hartree-Fock-relativistic method. Branching ratios and intensity factors were calculated for satellite lines, and dielectronic recombination rate coefficients were determined for the [Ni] 4s2 4p6 nl (n=4-7) singly excited states, as well as for the [Ni] 4s2 4p5 4 dnl , [Ni] 4s2 4p5 4 fnl , [Ni] 4 s 4p6 4 dnl , [Ni] 4 s 24p6 4 fnl , (n = 4-6), and [Ni] 4s2 4p5 5l' 5 l doubly excited nonautoionizing states. Contributions from the [Ni] 4 s 24p6 4 fnl (n = 6 - 7), [Ni] 4s2 4p5 5l' nl (n = 5 - 6), and [Ni] 4s2 4p5 6l' nl n = 6 - 7) doubly excited autoionizing states are evaluated numerically. Contributions from high-n states (n <= 200) were determined by using a scaling procedure and found to be very important for high temperatures. This research was supported by DOE under the NNSA Cooperative Agreement DE-NA0001984. Work at LLNL was performed under auspices of the US DOE under Contract No. DE-AC52-07NA27344.

  4. The relativistic equations of stellar structure and evolution

    NASA Technical Reports Server (NTRS)

    Thorne, K. S.

    1975-01-01

    The general relativistic equations of stellar structure and evolution are reformulated in a notation which makes easy contact with Newtonian theory. A general relativistic version of the mixing-length formalism for convection is presented. It is argued that in work on spherical systems, general relativity theorists have identified the wrong quantity as total mass-energy inside radius r.

  5. Coherent dissociation of relativistic {sup 12}N nuclei

    SciTech Connect

    Kattabekov, R. R.; Mamatkulov, K. Z.; Alikulov, S. S.; Artemenkov, D. A.; Bekmirzaev, R. N.; Bradnova, V.; Zarubin, P. I. Zarubina, I. G.; Kondratieva, N. V.; Kornegrutsa, N. K.; Krivenkov, D. O.; Malakhov, A. I.; Olimov, K.; Peresadko, N. G.; Polukhina, N. G.; Rukoyatkin, P. A.; Rusakova, V. V.; Stanoeva, R.; Kharlamov, S. P.

    2013-10-15

    The dissociation of relativistic {sup 12}N nuclei having a momentum of 2 GeV/c per nucleon and undergoing the most peripheral interactions in a track emulsion is studied. The picture of charged topology of product ensembles of relativistic fragments and special features of their angular distributions are presented.

  6. Kinetic analysis of thermally relativistic flow with dissipation

    NASA Astrophysics Data System (ADS)

    Yano, Ryosuke; Suzuki, Kojiro

    2011-01-01

    Nonequilibrium flow of thermally relativistic matter with dissipation is considered in the framework of the relativistic kinetic theory. As an object of the analysis, the supersonic rarefied flow of thermally relativistic matter around the triangle prism is analyzed using the Anderson-Witting model. Obtained numerical results indicate that the flow field changes in accordance with the flow velocity and temperature of the uniform flow owing to both effects derived from the Lorentz contraction and thermally relativistic effects, even when the Mach number of the uniform flow is fixed. The profiles of the heat flux along the stagnation streamline can be approximated on the basis of the relativistic Navier-Stokes-Fourier (NSF) law except for a strong nonequilibrium regime such as the middle of the shock wave and the vicinity of the wall, whereas the profile of the heat flux behind the triangle prism cannot be approximated on the basis of the relativistic NSF law owing to rarefied effects via the expansion behind the triangle prism. Additionally, the heat flux via the gradient of the static pressure is non-negligible owing to thermally relativistic effects. The profile of the dynamic pressure is different from that approximated on the basis of the NSF law, which is obtained by the Eckart decomposition. Finally, variations of convections of the mass and momentum owing to the effects derived from the Lorentz contraction and thermally relativistic effects are numerically confirmed.

  7. Relativistic effects in nuclear many-body systems

    SciTech Connect

    Coester, F.

    1985-01-01

    Different approaches to the formulation of relativistic many-body dynamics yield different perspectives of nature and the magnitude of ''relativistic effects''. The effects of Lorentz invariance appear to be relatively unimportant. Important dynamical features of spinorial many-body formalisms are effects of subnuclear degrees of freedom which are represented in the many-body forces of the covariant nuclear Hamiltonian. 24 refs.

  8. Particle Acceleration and Radiative Losses at Relativistic Shocks

    NASA Astrophysics Data System (ADS)

    Dempsey, P.; Duffy, P.

    A semi-analytic approach to the relativistic transport equation with isotropic diffusion and consistent radiative losses is presented. It is based on the eigenvalue method first introduced in Kirk & Schneider [5]and Heavens & Drury [3]. We demonstrate the pitch-angle dependence of the cut-off in relativistic shocks.

  9. Feynman's Relativistic Electrodynamics Paradox and the Aharonov-Bohm Effect

    NASA Astrophysics Data System (ADS)

    Caprez, Adam; Batelaan, Herman

    2009-03-01

    An analysis is done of a relativistic paradox posed in the Feynman Lectures of Physics involving two interacting charges. The physical system presented is compared with similar systems that also lead to relativistic paradoxes. The momentum conservation problem for these systems is presented. The relation between the presented analysis and the ongoing debates on momentum conservation in the Aharonov-Bohm problem is discussed.

  10. Kinetic analysis of thermally relativistic flow with dissipation

    SciTech Connect

    Yano, Ryosuke; Suzuki, Kojiro

    2011-01-15

    Nonequilibrium flow of thermally relativistic matter with dissipation is considered in the framework of the relativistic kinetic theory. As an object of the analysis, the supersonic rarefied flow of thermally relativistic matter around the triangle prism is analyzed using the Anderson-Witting model. Obtained numerical results indicate that the flow field changes in accordance with the flow velocity and temperature of the uniform flow owing to both effects derived from the Lorentz contraction and thermally relativistic effects, even when the Mach number of the uniform flow is fixed. The profiles of the heat flux along the stagnation streamline can be approximated on the basis of the relativistic Navier-Stokes-Fourier (NSF) law except for a strong nonequilibrium regime such as the middle of the shock wave and the vicinity of the wall, whereas the profile of the heat flux behind the triangle prism cannot be approximated on the basis of the relativistic NSF law owing to rarefied effects via the expansion behind the triangle prism. Additionally, the heat flux via the gradient of the static pressure is non-negligible owing to thermally relativistic effects. The profile of the dynamic pressure is different from that approximated on the basis of the NSF law, which is obtained by the Eckart decomposition. Finally, variations of convections of the mass and momentum owing to the effects derived from the Lorentz contraction and thermally relativistic effects are numerically confirmed.

  11. A highly accurate interatomic potential for argon

    NASA Astrophysics Data System (ADS)

    Aziz, Ronald A.

    1993-09-01

    A modified potential based on the individually damped model of Douketis, Scoles, Marchetti, Zen, and Thakkar [J. Chem. Phys. 76, 3057 (1982)] is presented which fits, within experimental error, the accurate ultraviolet (UV) vibration-rotation spectrum of argon determined by UV laser absorption spectroscopy by Herman, LaRocque, and Stoicheff [J. Chem. Phys. 89, 4535 (1988)]. Other literature potentials fail to do so. The potential also is shown to predict a large number of other properties and is probably the most accurate characterization of the argon interaction constructed to date.

  12. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect

    Cayatte, V.; Sauty, C.; Vlahakis, N.; Tsinganos, K.; Matsakos, T.; Lima, J. J. G.

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  13. Relativistic-beam Pickup Test Facility

    SciTech Connect

    Kramer, S.L.; Simpson, J.; Konecny, R.; Suddeth, D.

    1983-01-01

    The electrical response of pickups and cavities to charged particle beams has been an area of considerable activity and concern for accelerator systems. With the advent of stochastic beam cooling, the position and frequency response of beam pickups has become a crucial parameter in determining the performance of these systems. The most frequently used method for measuring and calibrating beam pickups has been the use of current carrying wires to simulate relativistic beams. This method has sometimes led to incorrect predictions of the pickup response to particle beams. The reasons for the differences are not always obvious but could arise from: (1) wires are incapable of exciting or permitting many of the modes that beams excite or (2) the interaction of the wire with large arrays of pickups produce results which are not easily predicted. At Argonne these deficiencies are resolved by calibrating pickups with a relativistic electron beam. This facility is being used extensively by several groups to measure beam pickup devices and is the primary calibration facility for pickups to be used in the FNAL TEV-I Antiproton Source.

  14. The Radiation Hydrodynamics of Relativistic Shear Flows

    NASA Astrophysics Data System (ADS)

    Coughlin, Eric R.; Begelman, Mitchell C.

    2016-07-01

    We present a method for analyzing the interaction between radiation and matter in regions of intense, relativistic shear that can arise in many astrophysical situations. We show that there is a simple velocity profile that should be manifested in regions of large shear that have “lost memory” of their boundary conditions, and we use this self-similar velocity profile to construct the surface of last scattering, or the τ ≃ 1 surface, as viewed from any comoving point within the flow. We demonstrate that a simple treatment of scattering from this τ ≃ 1 surface exactly conserves photon number, and we derive the rate at which the radiation field is heated due to the shear present in the flow. The components of the comoving radiation energy–momentum tensor are calculated, and we show that they have relatively simple, approximate forms that interpolate between the viscous (small shear) and streaming (large shear) limits. We put our expression for the energy–momentum tensor in a covariant form that does not depend on the explicit velocity profile within the fluid and, therefore, represents a natural means for analyzing general, radiation-dominated, relativistic shear flows.

  15. General-relativistic astrophysics. [gravitational wave astronomy

    NASA Technical Reports Server (NTRS)

    Thorne, K. S.

    1978-01-01

    The overall relevance of general relativity to astrophysics is considered, and some of the knowledge about the ways in which general relativity should influence astrophysical systems is reviewed. Attention is focused primarily on finite-sized astrophysical systems, such as stars, globular clusters, galactic nuclei, and primordial black holes. Stages in the evolution of such systems and tools for studying the effects of relativistic gravity in these systems are examined. Gravitational-wave astronomy is discussed in detail, with emphasis placed on estimates of the strongest gravitational waves that bathe earth, present obstacles and future prospects for detection of the predicted waves, the theory of small perturbations of relativistic stars and black holes, and the gravitational waves such objects generate. Characteristics of waves produced by black-hole events in general, pregalactic black-hole events, black-hole events in galactic nuclei and quasars, black-hole events in globular clusters, the collapse of normal stars to form black holes or neutron stars, and corequakes in neutron stars are analyzed. The state of the art in gravitational-wave detection and characteristics of various types of detector are described.

  16. Transport coefficients of a relativistic plasma

    NASA Astrophysics Data System (ADS)

    Pike, O. J.; Rose, S. J.

    2016-05-01

    In this work, a self-consistent transport theory for a relativistic plasma is developed. Using the notation of Braginskii [S. I. Braginskii, in Reviews of Plasma Physics, edited by M. A. Leontovich (Consultants Bureau, New York, 1965), Vol. 1, p. 174], we provide semianalytical forms of the electrical resistivity, thermoelectric, and thermal conductivity tensors for a Lorentzian plasma in a magnetic field. This treatment is then generalized to plasmas with arbitrary atomic number by numerically solving the linearized Boltzmann equation. The corresponding transport coefficients are fitted by rational functions in order to make them suitable for use in radiation-hydrodynamic simulations and transport calculations. Within the confines of linear transport theory and on the assumption that the plasma is optically thin, our results are valid for temperatures up to a few MeV. By contrast, classical transport theory begins to incur significant errors above kBT ˜10 keV, e.g., the parallel thermal conductivity is suppressed by 15% at kBT =20 keV due to relativistic effects.

  17. Prognosis of Gles of Relativistic Solar Protons

    NASA Astrophysics Data System (ADS)

    Pérez-Peraza, Jorge; Juárez-Zuñiga, Alan

    2015-04-01

    Ground level enhancements (GLEs) are relativistic solar particles measured at ground level by the worldwide network of cosmic ray detectors. These sporadic events are associated with solar flares and are assumed to be of a quasi-random nature. Studying them gives information about their source and propagation processes, the maximum capacity of the Sun as a particle accelerator engine, the magnetic structure of the medium traversed, etc. Space vehicles, as well as electric transformers and gas pipes at high latitudes may be damaged by this kind of radiation. As a result, their prediction has turned out to be very important, but because of their random occurrence, up to now few efforts toward this goal have been made. The results of these efforts have been limited to possible warnings in real time, just before a GLE occurrence, but no specific dates have been predicted well enough in advance to prevent possible hazards. In this study we show that, in spite of the quasi-stochastic nature of GLEs, it is possible to predict them with relative precision, even for future solar cycles. Additionally, a previous study establishing synchronization among some periodicities of several layers of solar atmosphere argues against the full randomness of the phenomenon of relativistic particle production. Therefore, by means of wavelet spectral analysis combined with fuzzy logic tools, we reproduce previous known GLE events and present results for future events. The next GLE is expected to occur in the first semester of 2016.

  18. Relativistic redshifts in quasar broad lines

    SciTech Connect

    Tremaine, Scott; Shen, Yue; Liu, Xin; Loeb, Abraham E-mail: yshen@obs.carnegiescience.edu E-mail: aloeb@cfa.harvard.edu

    2014-10-10

    The broad emission lines commonly seen in quasar spectra have velocity widths of a few percent of the speed of light, so special- and general-relativistic effects have a significant influence on the line profile. We have determined the redshift of the broad Hβ line in the quasar rest frame (determined from the core component of the [O III] line) for over 20,000 quasars from the Sloan Digital Sky Survey Data Release 7 quasar catalog. The mean redshift as a function of line width is approximately consistent with the relativistic redshift that is expected if the line originates in a randomly oriented Keplerian disk that is obscured when the inclination of the disk to the line of sight exceeds ∼30°-45°, consistent with simple active galactic nucleus unification schemes. This result also implies that the net line-of-sight inflow/outflow velocities in the broad-line region are much less than the Keplerian velocity when averaged over a large sample of quasars with a given line width.

  19. 3D Hydrodynamic Simulations of Relativistic Jets

    NASA Astrophysics Data System (ADS)

    Hughes, P. A.; Miller, M. A.; Duncan, G. C.; Swift, C. M.

    1998-12-01

    We present the results of validation runs and the first extragalactic jet simulations performed with a 3D relativistic numerical hydrodynamic code employing a solver of the RHLLE type and using adaptive mesh refinement (AMR; Duncan & Hughes, 1994, Ap. J., 436, L119). Test problems include the shock tube, blast wave and spherical shock reflection (implosion). Trials with the code show that as a consequence of AMR it is viable to perform exploratory runs on workstation class machines (with no more than 128Mb of memory) prior to production runs. In the former case we achieve a resolution not much less than that normally regarded as the minimum needed to capture the essential physics of a problem, which means that such runs can provide valuable guidance allowing the optimum use of supercomputer resources. We present initial results from a program to explore the 3D stability properties of flows previously studied using a 2D axisymmetric code, and our first attempt to explore the structure and morphology of a relativistic jet encountering an ambient density gradient that mimics an ambient inhomogeneity or cloud.

  20. A New Relativistic Jet Model of Blazars

    NASA Astrophysics Data System (ADS)

    Webb, James; Benitez, Erika; Howard, Emily

    1998-11-01

    The subclass of Active galaxies called Blazars encompass the most intrinsically luminous and rapidly variable sources known to astrophysicists. Attempts to model these sources has largely been frustrated due in part to observational difficulties, but also due to the lack of theoretical models capable of explaining the different characteristics of the observed sources. Leading candidate models all incorporate a massive, rotating black hole which is accreting galactic material, with some of this material being ejected out the ratational axis of the hole in the form of relativistically expanding jets. These jets are thought to emit energy via the synchrotron process across the entire spectrum from radio frequences all the way through the GEV (sometimes TEV) gamma-ray frequencies. Attempts to model these sources with single relativistic jets has proven difficult. We present a new model which features concentric interacting jets that do a much better job of explaining the types of Blazars we observe. We also discuss ways of testing this new model against multifreuqency observations.

  1. Balloon Observations of Relativistic Electron Precipitation

    NASA Astrophysics Data System (ADS)

    Millan, R. M.; Woodger, L. A.

    2015-12-01

    Relativistic electron precipitation events lasting from minutes to hours have been observed by balloon-borne instrumentation since 1996. This collection of observations, including the recent BARREL observations, all occur in the noon to midnight sector. EMIC waves have been suggested as the precipitation mechanism for this type of event [Lorentzen et al., 2000 and Millan et al., 2002]. A recent study by Li et al., [2014] performed a case study which modeled the radiation belt relativistic electron pitch angle diffusion from EMIC waves which showed convincing agreement between the modeled results and the BARREL x-ray observations. A survey of the BARREL REP events suggests this type of precipitation is a very localized phenomena with most events only being observed by a single balloon at a time despite the extensive L-value and local time coverage of observations during the campaign. This result is consistent with the findings of Blum et al., [2013]. Furthermore, the balloon observations show local time energy dependence consistent with the SAMPEX observations reported by Comess et al, [2013]. In this work we address the following questions: based on the REP events observed by balloon-borne instrumentation, are these characteristics true for all identified REP events and does this support EMIC waves as the precipitation mechanism? Due to the localized region of precipitation, do these events represent a significant radiation belt loss process?

  2. CAFE: A New Relativistic MHD Code

    NASA Astrophysics Data System (ADS)

    Lora-Clavijo, F. D.; Cruz-Osorio, A.; Guzmán, F. S.

    2015-06-01

    We introduce CAFE, a new independent code designed to solve the equations of relativistic ideal magnetohydrodynamics (RMHD) in three dimensions. We present the standard tests for an RMHD code and for the relativistic hydrodynamics regime because we have not reported them before. The tests include the one-dimensional Riemann problems related to blast waves, head-on collisions of streams, and states with transverse velocities, with and without magnetic field, which is aligned or transverse, constant or discontinuous across the initial discontinuity. Among the two-dimensional (2D) and 3D tests without magnetic field, we include the 2D Riemann problem, a one-dimensional shock tube along a diagonal, the high-speed Emery wind tunnel, the Kelvin-Helmholtz (KH) instability, a set of jets, and a 3D spherical blast wave, whereas in the presence of a magnetic field we show the magnetic rotor, the cylindrical explosion, a case of Kelvin-Helmholtz instability, and a 3D magnetic field advection loop. The code uses high-resolution shock-capturing methods, and we present the error analysis for a combination that uses the Harten, Lax, van Leer, and Einfeldt (HLLE) flux formula combined with a linear, piecewise parabolic method and fifth-order weighted essentially nonoscillatory reconstructors. We use the flux-constrained transport and the divergence cleaning methods to control the divergence-free magnetic field constraint.

  3. Electromagnetic wave equations for relativistically degenerate quantum magnetoplasmas.

    PubMed

    Masood, Waqas; Eliasson, Bengt; Shukla, Padma K

    2010-06-01

    A generalized set of nonlinear electromagnetic quantum hydrodynamic (QHD) equations is derived for a magnetized quantum plasma, including collisional, electron spin- 1/2, and relativistically degenerate electron pressure effects that are relevant for dense astrophysical systems, such as white dwarfs. For illustrative purposes, linear dispersion relations are derived for one-dimensional magnetoacoustic waves for a collisionless nonrelativistic degenerate gas in the presence of the electron spin- 1/2 contribution and for magnetoacoustic waves in a plasma containing relativistically degenerate electrons. It is found that both the spin and relativistic degeneracy at high densities tend to slow down the magnetoacoustic wave due to the Pauli paramagnetic effect and relativistic electron mass increase. The present study outlines the theoretical framework for the investigation of linear and nonlinear behaviors of electromagnetic waves in dense astrophysical systems. The results are applied to calculate the magnetoacoustic speeds for both the nonrelativistic and relativistic electron degeneracy cases typical for white dwarf stars. PMID:20866534

  4. Nonlinear positron-acoustic waves in fully relativistic degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Hossen, M. A.; Mamun, A. A.

    2016-03-01

    The nonlinear positron-acoustic (PA) waves propagating in a fully relativistic electron-positron-ion (EPI) plasma (containing degenerate electrons and positrons, and immobile heavy ions) have been theoretically investigated. A fully relativistic hydrodynamic model, which is consistent with the relativistic principle has been used, and the reductive perturbation method is employed to derive the dynamical Korteweg-de Vries equation. The dynamics of electrons as well as positrons, and the presence of immobile heavy ions are taken into account. It is found that the effects of relativistic degeneracy of electrons and positrons, static heavy ions, plasma particles velocity, enthalpy, etc have significantly modified the basic properties of the PA solitary waves propagating in the fully relativistic EPI plasmas. The application of the results of our present work in astrophysical compact objects such as white dwarfs and neutron stars, etc are briefly discussed.

  5. A Very-High-Specific-Impulse Relativistic Laser Thruster

    SciTech Connect

    Horisawa, Hideyuki; Kimura, Itsuro

    2008-04-28

    Characteristics of compact laser plasma accelerators utilizing high-power laser and thin-target interaction were reviewed as a potential candidate of future spacecraft thrusters capable of generating relativistic plasma beams for interstellar missions. Based on the special theory of relativity, motion of the relativistic plasma beam exhausted from the thruster was formulated. Relationships of thrust, specific impulse, input power and momentum coupling coefficient for the relativistic plasma thruster were derived. It was shown that under relativistic conditions, the thrust could be extremely large even with a small amount of propellant flow rate. Moreover, it was shown that for a given value of input power thrust tended to approach the value of the photon rocket under the relativistic conditions regardless of the propellant flow rate.

  6. Trans-Relativistic Particle Acceleration in Astrophysical Plasmas

    NASA Astrophysics Data System (ADS)

    Becker, Peter A.; Subramanian, P.

    2014-01-01

    Trans-relativistic particle acceleration due to Fermi interactions between charged particles and MHD waves helps to power the observed high-energy emission in AGN transients and solar flares. The trans-relativistic acceleration process is challenging to treat analytically due to the complicated momentum dependence of the momentum diffusion coefficient. For this reason, most existing analytical treatments of particle acceleration assume that the injected seed particles are already relativistic, and therefore they are not suited to study trans-relativistic acceleration. The lack of an analytical model has forced workers to rely on numerical simulations to obtain particle spectra describing the trans-relativistic case. In this work we present the first analytical solution to the global, trans-relativistic problem describing the acceleration of seed particles due to hard-sphere collisions with MHD waves. The new results include the exact solution for the steady-state Green's function resulting from the continual injection of monoenergetic seed particles with an arbitrary energy. We also introduce an approximate treatment of the trans-relativistic acceleration process based on a hybrid form for the momentum diffusion coefficient, given by the sum of the two asymptotic forms. We refer to this process as "quasi hard-sphere scattering." The main advantage of the hybrid approximation is that it allows the extension of the physical model to include (i) the effects of synchrotron and inverse-Compton losses and (ii) time dependence. The new analytical results can be used to model the trans-relativistic acceleration of particles in AGN and solar environments, and can also be used to compute the spectra of the associated synchrotron and inverse-Compton emission. Applications of both types are discussed. We highlight (i) relativistic ion acceleration in black hole accretion coronae, and (ii) the production of gyrosynchrotron microwave emission due to relativistic electron

  7. Formation of Relativistic Jets : Magnetohydrodynamics and Synchrotron Radiation

    NASA Astrophysics Data System (ADS)

    Porth, Oliver J. G.

    2011-11-01

    In this thesis, the formation of relativistic jets is investigated by means of special relativistic magnetohydrodynamic simulations and synchrotron radiative transfer. Our results show that the magnetohydrodynamic jet self-collimation paradigm can also be applied to the relativistic case. In the first part, jets launched from rotating hot accretion disk coronae are explored, leading to well collimated, but only mildly relativistic flows. Beyond the light-cylinder, the electric charge separation force balances the classical trans-field Lorentz force almost entirely, resulting in a decreased efficiency of acceleration and collimation in comparison to non-relativistic disk winds. In the second part, we examine Poynting dominated flows of various electric current distributions. By following the outflow for over 3000 Schwarzschild radii, highly relativistic jets of Lorentz factor 8 and half-opening angles below 1 degree are obtained, providing dynamical models for the parsec scale jets of active galactic nuclei. Applying the magnetohydrodynamic structure of the quasi-stationary simulation models, we solve the relativistically beamed synchrotron radiation transport. This yields synthetic radiation maps and polarization patterns that can be used to confront high resolution radio and (sub-) mm observations of nearby active galactic nuclei. Relativistic motion together with the helical magnetic fields of the jet formation site imprint a clear signature on the observed polarization and Faraday rotation. In particular, asymmetries in the polarization direction across the jet can disclose the handedness of the magnetic helix and thus the spin direction of the central engine. Finally, we show first results from fully three-dimensional, high resolution adaptive mesh refinement simulations of jet formation from a rotating magnetosphere and examine the jet stability. Relativistic field-line rotation leads to an electric charge separation force that opposes the magnetic Lorentz

  8. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  9. Stationary phase method and delay times for relativistic and non-relativistic tunneling particles

    NASA Astrophysics Data System (ADS)

    Bernardini, A. E.

    2009-06-01

    The stationary phase method is frequently adopted for calculating tunneling phase times of analytically-continuous Gaussian or infinite-bandwidth step pulses which collide with a potential barrier. This report deals with the basic concepts on deducing transit times for quantum scattering: the stationary phase method and its relation with delay times for relativistic and non-relativistic tunneling particles. After reexamining the above-barrier diffusion problem, we notice that the applicability of this method is constrained by several subtleties in deriving the phase time that describes the localization of scattered wave packets. Using a recently developed procedure - multiple wave packet decomposition - for some specifical colliding configurations, we demonstrate that the analytical difficulties arising when the stationary phase method is applied for obtaining phase (traversal) times are all overcome. In this case, we also investigate the general relation between phase times and dwell times for quantum tunneling/scattering. Considering a symmetrical collision of two identical wave packets with an one-dimensional barrier, we demonstrate that these two distinct transit time definitions are explicitly connected. The traversal times are obtained for a symmetrized (two identical bosons) and an antisymmetrized (two identical fermions) quantum colliding configuration. Multiple wave packet decomposition shows us that the phase time (group delay) describes the exact position of the scattered particles and, in addition to the exact relation with the dwell time, leads to correct conceptual understanding of both transit time definitions. At last, we extend the non-relativistic formalism to the solutions for the tunneling zone of a one-dimensional electrostatic potential in the relativistic (Dirac to Klein-Gordon) wave equation where the incoming wave packet exhibits the possibility of being almost totally transmitted through the potential barrier. The conditions for the

  10. Rescattering effects on intensity interferometry and initial conditions in relativistic heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Li, Yang

    The properties of the quark-gluon plasma are being thoroughly studied by utilizing relativistic heavy ion collisions. After its invention in astronomy in the 1950s, intensity interferometry was found to be a robust method to probe the spatial and temporal information of the nuclear collisions also. Although rescattering effects are negligible in elementary particle collisions, it may be very important for heavy ion collisions at RHIC and in the future LHC. Rescattering after production will modify the measured correlation function and make it harder to extract the dynamical information from data. To better understand the data which are dimmed by this final state process, we derive a general formula for intensity interferometry which can calculate rescattering effects easily. The formula can be used both non-relativistically and relativistically. Numerically, we found that rescattering effects on kaon interferometry for RHIC experiments can modify the measured ratio of the outward radius to the sideward radius, which is a sensitive probe to the equation of state, by as large as 15%. It is a nontrivial contribution which should be included to understand the data more accurately. The second part of this thesis is on the initial conditions in relativistic heavy ion collisions. Although relativistic hydrodynamics is successful in explaining many aspects of the data, it is only valid after some finite time after nuclear contact. The results depend on the choice of initial conditions which, so far, have been very uncertain. I describe a formula based on the McLerran-Venugopalan model to compute the initial energy density. The soft gluon fields produced immediately after the overlap of the nuclei can be expanded as a power series of the proper time t. Solving Yang-Mills equations with color current conservation can give us the analytical formulas for the fields. The local color charges on the transverse plane are stochastic variables and have to be taken care of by random

  11. Relativistic electron beam acceleration by Compton scattering of extraordinary waves

    SciTech Connect

    Sugaya, R.

    2006-05-15

    Relativistic transport equations, which demonstrate that relativistic and nonrelativistic particle acceleration along and across a magnetic field and the generation of an electric field transverse to the magnetic field, are induced by nonlinear wave-particle scattering (nonlinear Landau and cyclotron damping) of almost perpendicularly propagating electromagnetic waves in a relativistic magnetized plasma were derived from the relativistic Vlasov-Maxwell equations. The relativistic transport equations show that electromagnetic waves can accelerate particles in the k{sup ''} direction (k{sup ''}=k-k{sup '}). Simultaneously, an intense cross-field electric field, E{sub 0}=B{sub 0}xv{sub d}/c, is generated via the dynamo effect owing to perpendicular particle drift to satisfy the generalized Ohm's law, which means that this cross-field particle drift is identical to the ExB drift. On the basis of these equations, acceleration and heating of a relativistic electron beam due to nonlinear wave-particle scattering of electromagnetic waves in a magnetized plasma were investigated theoretically and numerically. Two electromagnetic waves interact nonlinearly with the relativistic electron beam, satisfying the resonance condition of {omega}{sub k}-{omega}{sub k{sup '}}-(k{sub perpendicular}-k{sub perpendicula=} r{sup '})v{sub d}-(k{sub parallel}-k{sub parallel}{sup '})v{sub b}{approx_equal}m{omega}{sub ce}, where v{sub b} and v{sub d} are the parallel and perpendicular velocities of the relativistic electron beam, respectively, and {omega}{sub ce} is the relativistic electron cyclotron frequency. The relativistic transport equations using the relativistic drifted Maxwellian momentum distribution function of the relativistic electron beam were derived and analyzed. It was verified numerically that extraordinary waves can accelerate the highly relativistic electron beam efficiently with {beta}m{sub e}c{sup 2} < or approx. 1 GeV, where {beta}=(1-v{sub b}{sup 2}/c{sup 2}){sup -1/2}.

  12. Relativistic three-partite non-locality

    NASA Astrophysics Data System (ADS)

    Moradpour, Hooman; Montakhab, Afshin

    2016-05-01

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

  13. Interaction of Relativistic Jets with Their Environments

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna; Begelman, M. C.

    2014-01-01

    Relativistic jets such as those emitted by active galactic nuclei are observed to be collimated over great distances, but the cause of this collimation is uncertain. Also not fully understood are the means by which these jets become accelerated to their extreme velocities. To probe these questions, I examine the possibility of collimation and acceleration of relativistic jets by the pressure of the ambient medium surrounding the jet base, in the limit in which the jet interior has lost causal contact with its surroundings. I model the jet with an ultrarelativistic equation of state, injected into an ambient medium that has a pressure that decreases as a power of spherical radius, p ~ r^-n. Within the range 2relativistic jets that are created by some tidal disruption events --- events in which a star passing near a supermassive black hole (SMBH) is torn apart by tidal forces, and the star material then accretes back onto the SMBH --- such as in the observations of Swift

  14. Ab initio and relativistic DFT study of spin–rotation and NMR shielding constants in XF{sub 6} molecules, X = S, Se, Te, Mo, and W

    SciTech Connect

    Ruud, Kenneth; Demissie, Taye B.; Jaszuński, Michał

    2014-05-21

    We present an analysis of the spin–rotation and absolute shielding constants of XF{sub 6} molecules (X = S, Se, Te, Mo, W) based on ab initio coupled cluster and four-component relativistic density-functional theory (DFT) calculations. The results show that the relativistic contributions to the spin–rotation and shielding constants are large both for the heavy elements as well as for the fluorine nuclei. In most cases, incorporating the computed relativistic corrections significantly improves the agreement between our results and the well-established experimental values for the isotropic spin–rotation constants and their anisotropic components. This suggests that also for the other molecules, for which accurate and reliable experimental data are not available, reliable values of spin–rotation and absolute shielding constants were determined combining ab initio and relativistic DFT calculations. For the heavy nuclei, the breakdown of the relationship between the spin–rotation constant and the paramagnetic contribution to the shielding constant, due to relativistic effects, causes a significant error in the total absolute shielding constants.

  15. Feedback about More Accurate versus Less Accurate Trials: Differential Effects on Self-Confidence and Activation

    ERIC Educational Resources Information Center

    Badami, Rokhsareh; VaezMousavi, Mohammad; Wulf, Gabriele; Namazizadeh, Mahdi

    2012-01-01

    One purpose of the present study was to examine whether self-confidence or anxiety would be differentially affected by feedback from more accurate rather than less accurate trials. The second purpose was to determine whether arousal variations (activation) would predict performance. On Day 1, participants performed a golf putting task under one of…

  16. A new relativistic theory: a relativistic scheme by eliminating small components (RESC)

    NASA Astrophysics Data System (ADS)

    Nakajima, Takahito; Hirao, Kimihiko

    1999-03-01

    A new relativistic theory has been proposed by the elimination of small components of the Dirac equation. It is variationally stable and can easily be incorporated into any electronic structure theory. The present formalism is tested in standard problems of Ag and Au atoms and their hydrides at various levels of theory including single- and multi-reference-based methods. Numerical results show that good accuracy can be obtained.

  17. Relativistic mean field model for entrainment in general relativistic superfluid neutron stars

    NASA Astrophysics Data System (ADS)

    Comer, G. L.; Joynt, R.

    2003-07-01

    General relativistic superfluid neutron stars have a significantly more intricate dynamics than their ordinary fluid counterparts. Superfluidity allows different superfluid (and superconducting) species of particles to have independent fluid flows, a consequence of which is that the fluid equations of motion contain as many fluid element velocities as superfluid species. Whenever the particles of one superfluid interact with those of another, the momentum of each superfluid will be a linear combination of both superfluid velocities. This leads to the so-called entrainment effect whereby the motion of one superfluid will induce a momentum in the other superfluid. We have constructed a fully relativistic model for entrainment between superfluid neutrons and superconducting protons using a relativistic σ-ω mean field model for the nucleons and their interactions. In this context there are two notions of “relativistic”: relativistic motion of the individual nucleons with respect to a local region of the star (i.e. a fluid element containing, say, an Avogadro’s number of particles), and the motion of fluid elements with respect to the rest of the star. While it is the case that the fluid elements will typically maintain average speeds at a fraction of that of light, the supranuclear densities in the core of a neutron star can make the nucleons themselves have quite high average speeds within each fluid element. The formalism is applied to the problem of slowly rotating superfluid neutron star configurations, a distinguishing characteristic being that the neutrons can rotate at a rate different from that of the protons.

  18. Feedback about more accurate versus less accurate trials: differential effects on self-confidence and activation.

    PubMed

    Badami, Rokhsareh; VaezMousavi, Mohammad; Wulf, Gabriele; Namazizadeh, Mahdi

    2012-06-01

    One purpose of the present study was to examine whether self-confidence or anxiety would be differentially affected byfeedback from more accurate rather than less accurate trials. The second purpose was to determine whether arousal variations (activation) would predict performance. On day 1, participants performed a golf putting task under one of two conditions: one group received feedback on the most accurate trials, whereas another group received feedback on the least accurate trials. On day 2, participants completed an anxiety questionnaire and performed a retention test. Shin conductance level, as a measure of arousal, was determined. The results indicated that feedback about more accurate trials resulted in more effective learning as well as increased self-confidence. Also, activation was a predictor of performance. PMID:22808705

  19. Exact evolution of discrete relativistic cosmological models

    SciTech Connect

    Clifton, Timothy; Tavakol, Reza; Gregoris, Daniele; Rosquist, Kjell E-mail: danielegregoris@libero.it E-mail: r.tavakol@qmul.ac.uk

    2013-11-01

    We study the effects of inhomogeneities on the evolution of the Universe, by considering a range of cosmological models with discretized matter content. This is done using exact and fully relativistic methods that exploit the symmetries in and about submanifolds of spacetimes that themselves possess no continuous global symmetries. These methods allow us to follow the evolution of our models throughout their entire history, far beyond what has previously been possible. We find that while some space-like curves collapse to anisotropic singularities in finite time, others remain non-singular forever. The resulting picture is of a cosmological spacetime in which some behaviour remains close to Friedmann-like, while other behaviours deviate radically. In particular, we find that large-scale acceleration is possible without any violation of the energy conditions.

  20. Improving general relativistic astrophysics workflows with ADIOS

    NASA Astrophysics Data System (ADS)

    Bode, Tanja; Slawinska, Magdalena; Logan, Jeremy; Clark, Michael; Kinsey, Matthew; Wolf, Matthew; Klasky, Scott; Laguna, Pablo

    2013-04-01

    There are many challenges in analyzing and visualizing data from current cutting-edge general relativistic astrophysics simulations. Many of the associated tasks are time-consuming, with large performance degradation due to the magnitude and complexity of the data. The Adaptable IO System (ADIOS) is a componentization of the IO layer that has demonstrated remarkable IO performance improvements on applications running on leadership class machines while also offering new in-memory ``staging'' operations for transforming data in situ. We have incorporated ADIOS staging technologies into our Maya numerical relativity code based on Cactus infrastructure and Carpet mesh refinement. We present results that demonstrate how ADIOS yields significant gains on IO performance while utilizing leveraged investments in ADIOS plugins for visualization tools such as VisIt.