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Equivalence principles are a major part of modern relativity theory. Gravitational shifts can already be calculated within the time domain as motion shifts, and we examine the consequences of reversing this argument and describing motion…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Eric Baird

The macroscopic behaviour of cosmic rays in turbulent magnetic fields is discussed. An implementation of anisotropic diffusion of cosmic rays with respect to the magnetic field in a non-conservative, high-order, finite-difference…

Astrophysics · Physics 2008-11-26 A. P. Snodin , Axel Brandenburg , A. J. Mee , Anvar Shukurov

We consider the possibility that the ultra-high-energy cosmic ray flux has a small component of exotic particles which create showers much deeper in the atmosphere than ordinary hadronic primaries. It is shown that applying the conventional…

Astrophysics · Physics 2008-11-26 Aaron S. Chou

We present a general and practical procedure to solve the general relativistic hydrodynamic equations by using any of the special relativistic Riemann solvers recently developed for describing the evolution of special relativistic flows.…

Astrophysics · Physics 2007-05-23 Jose A. Pons , Jose A. Font , Jose M. Ibanez , Jose M. Marti , Juan A. Miralles

Simulations are made of a probe particle diffusing through a complex fluid. Probe particle motions are described by the Mori-Zwanzig equation and Mori's orthogonal hierarchy of random forces scheme, subject to the approximation that the…

Soft Condensed Matter · Physics 2014-06-20 George D. J. Phillies

A new Riemannian geometry for the Compound Gaussian distribution is proposed. In particular, the Fisher information metric is obtained, along with corresponding geodesics and distance function. This new geometry is applied on a change…

Machine Learning · Statistics 2020-05-21 Florent Bouchard , Ammar Mian , Jialun Zhou , Salem Said , Guillaume Ginolhac , Yannick Berthoumieu

We have developed a new formulation to obtain self-gravitating, axisymmetric configurations in permanent rotation. The formulation is based on the Lagrangian variational principle, and treats not only barotropic but also baroclinic…

Solar and Stellar Astrophysics · Physics 2017-03-15 Nobutoshi Yasutake , Kotaro Fujisawa , Shoichi Yamada

A Monte Carlo based computer model is presented to comprehend the contrasting observations of Mazumder et al. [Phys. Rev. Lett. 93, 255704 (2004) and Phys. Rev. B 72, 224208 (2005)], based on neutron-scattering measurements, on temporal…

Materials Science · Physics 2015-05-27 T. Mazumdar , S. Mazumderand D. Sen

Explicit formulae of the equations in the generalized Galileon models are given. We also develop the formulation of the reconstruction. By using the formulation, we can explicitly construct an action which reproduces an arbitrary…

High Energy Physics - Theory · Physics 2015-06-04 Norihito Shirai , Kazuharu Bamba , Shota Kumekawa , Jiro Matsumoto , Shin'ichi Nojiri

We develop the reconstruction program for the number of modified gravities: scalar-tensor theory, $f(R)$, $F(G)$ and string-inspired, scalar-Gauss-Bonnet gravity. The known (classical) universe expansion history is used for the explicit and…

High Energy Physics - Theory · Physics 2010-04-06 Shin'ichi Nojiri , Sergei D. Odintsov

In this review I give a summary of the state-of-the-art for what concerns the chemo-dynamical numerical modelling of galaxies in general and of dwarf galaxies in particular. In particular, I focus my attention on (i) initial conditions;…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 S. Recchi

This paper updates and complements a previously published evaluation of computational methods for total and partial cross sections, relevant to modeling the photoelectric effect in Monte Carlo particle transport. It examines calculation…

Computational Physics · Physics 2020-02-14 Tullio Basaglia , Maria Grazia Pia , Paolo Saracco

Cosmological simulations still lack numerical resolution or physical processes to simulate dwarf galaxies in sufficient details. Accurate numerical simulations of individual dwarf galaxies are thus still in demand. We aim at (i) studying in…

Astrophysics of Galaxies · Physics 2015-04-20 Eduard I. Vorobyov , Simone Recchi , Gerhard Hensler

In this article we present the cosmological equivalence between the relativistic Finsler-Randers cosmology, with dark energy and modified gravity constructions, at the background level. Starting from a small deviation from the quadraticity…

General Relativity and Quantum Cosmology · Physics 2013-12-17 Spyros Basilakos , Alexandros P. Kouretsis , Emmanuel N. Saridakis , Panayiotis Stavrinos

The crucial but undocumented Dolan-McCrea variational method is richly applied. Using the said method, we analytically derived a field equation comprising entirely of geometric structures and we investigate how effectively it describes…

General Relativity and Quantum Cosmology · Physics 2017-04-20 Christian Nwachioma , Farida Tahir

The Schr\"odinger equation is universally accepted due to its excellent predictions aligning with observed results within its defined conditions. Nevertheless, it does not seem to possess the simplicity of fundamental laws, such as Newton's…

Quantum Physics · Physics 2023-10-20 Xuefeng Bao

In this brief review, we present the results of the fractional differential approach in cosmology in the context of the exact models of cosmological accelerated expansion obtained by several authors to date. Most of these studies are…

General Relativity and Quantum Cosmology · Physics 2021-05-18 V. K. Shchigolev

This paper exploits the theory of geometric gradient flows to introduce an alternative regularization of the thin-film equation. The solution properties of this regularization are investigated via a sequence of numerical simulations whose…

Fluid Dynamics · Physics 2020-02-20 Darryl D. Holm , Lennon Ó Náraigh , Cesare Tronci

The origin of the highest energy cosmic rays represents one of the most conspicuous enigmas of modern astrophysics, in spite of gigantic experimental efforts in the past fifty years, and of active theoretical research. The past decade has…

High Energy Astrophysical Phenomena · Physics 2015-06-11 M. Lemoine

The gravitational evolution of the cosmic one-point probability distribution function (PDF) has been estimated using an analytic approximation that combines gravitational perturbation theory with the Edgeworth expansion around a Gaussian…

Astrophysics · Physics 2009-10-31 E. Gaztanaga , P. Fosalba , E. Elizalde
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