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The evolution of the Universe is the ultimate laboratory to study fundamental physics across energy scales that span about 25 orders of magnitude: from the grand unification scale through particle and nuclear physics scales down to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. Boyanovsky , H. J. de Vega , D. J. Schwarz

The time-dependent spectral profile of a resonance line in a homogeneous expanding medium is studied by numerically solving an improved Fokker-Planck diffusion equation. The solutions are used to determine the time required to reach a…

Astrophysics · Physics 2009-10-22 George B. Rybicki , Ian P. Dell'Antonio

Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-13 R. Norris Keeler , Carl H. Gibson

We generalize the spherical collapse model for the formation of bound objects to apply in a Universe with arbitrary positive cosmological constant. We calculate the critical condition for collapse of an overdense region and give exact…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas , Yehuda Hoffman

In this paper we argue that it is possible to model the Universe along thermodynamic lines, using oscillators in the background Dark Energy at the Planck scale. This leads to meaningful results in agreement with observation.

General Physics · Physics 2008-10-31 B. G. Sidharth

The classical Friedmann-Lema\^itre equations are solved using a corrected version of Planck's radiation law. The function curves of the scale parameter a(t) and the variations with temperature a(T) and t(T) are given. It is shown that a…

General Relativity and Quantum Cosmology · Physics 2014-10-08 Rainer Collier

Alternative approach for description of the non-equilibrium phenomena arising in solids at a severe external loading is analyzed. The approach is based on the new form of kinetic equations in terms of the internal and modified free energy.…

Statistical Mechanics · Physics 2014-08-27 L. S. Metlov

We present a kinetic theory for the evolution of the phase-space distribution of dark matter particles in galaxy halos in the presence of a cosmological spectrum of fluctuations. This theory introduces a new way to model the formation and…

Astrophysics · Physics 2009-11-10 Chung-Pei Ma , Edmund Bertschinger

We derive an equation for the evolution of the number density of a massive particle species in the early Universe, which correctly accounts for the Fermi-Dirac (FD) statistics. The FD-corrections are sizable and potentially important if the…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. D. Dolgov , K. Kainulainen

We have developed a two-dimensional orbit averaged Fokker-Planck model of stellar clusters which expands on spherically symmetric one-dimensional models to include rotation and ellipticity. Physical effects such as collisions, finite…

Astrophysics · Physics 2007-05-23 J. Girash

We study the Universe evolution starting from the sub-Planckian scale to present times. The requirement for an exponential expansion of the space with the observed metric as a final stage leads to significant restrictions on the parameter…

General Relativity and Quantum Cosmology · Physics 2023-04-20 P. M. Petryakova , Arkady A. Popov , Sergey G. Rubin

We review the current issues of nonequilibrium phase transitions, in particular, in the early universe. Phase transitions cannot maintain thermal equilibrium and become nonequilibrium when the thermal relaxation time scale is greater than…

High Energy Physics - Phenomenology · Physics 2009-11-10 Sang Pyo Kim

Assuming that the background geometry is filled with free gas consisting of matter and radiation and no phase transitions being occurred in the early Universe, we discuss the thermodynamics of this {\it closed} system using classical…

General Relativity and Quantum Cosmology · Physics 2015-05-30 A. Tawfik , H. Magdy

The problem of diffusion in a time-dependent (and generally inhomogeneous) external field is considered on the basis of a generalized master equation with two times, introduced in [1,2]. We consider the case of the quasi Fokker-Planck…

Statistical Mechanics · Physics 2015-05-18 S. A. Trigger , G. J. F. van Heijst , O. F. Petrov , P. P. J. M. Schram

High-energy, multi-component plasmas in which pair creation and annihilation, lepton-lepton scattering, lepton-proton scattering, and Comptonization all contribute to establishing the particle and photon distributions, are present in a…

Astrophysics · Physics 2014-10-13 Sergei Nayakshin , Fulvio Melia

Loop quantum cosmology (LQC) is very powerful to deal with the behavior of early universe. And the effective loop quantum cosmology gives a successful description of the universe in the semiclassical region. We consider the apparent horizon…

General Relativity and Quantum Cosmology · Physics 2010-04-15 Li-Fang Li , Jian-Yang Zhu

A class of linear evolutionary equations with material laws involving fractional time-derivatives is considered. The main result is well-posedness and causality for this problem class. The approach is illustrated with two examples: a…

Analysis of PDEs · Mathematics 2013-04-10 Rainer Picard

We present the first post core collapse models of initially rotating star clusters, using the numerical solution of an orbit-averaged 2D Fokker-Planck equation. Based on the code developed by Einsel & Spurzem (1999), we have improved the…

Astrophysics · Physics 2009-11-07 Eunhyeuk Kim , Christian Einsel , Hyung Mok Lee , Rainer Spurzem , Myung Gyoon Lee

The stochastic differential equations for a model of dissipative particle dynamics with both total energy and total momentum conservation in the particle-particle interactions are presented. The corresponding Fokker-Planck equation for the…

Statistical Mechanics · Physics 2009-10-30 J. Bonet Avalos , A. D. Mackie

The dynamics is studied of an infinite continuum system of jumping and coalescing point particles. In the course of jumps, the particles repel each other whereas their coalescence is free. As the equation of motion we take a kinetic…

Dynamical Systems · Mathematics 2020-07-28 Kozitsky Yuri , Omelyan Igor , Pilorz Krzysztof