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Related papers: Theoretical results on the Universe structure

200 papers

In a homogeneous and isotropic universe with non-zero spatial curvature we consider the effects of gravitational particle production in the dynamics of the universe. We show that the dynamics of the universe in such a background is…

General Relativity and Quantum Cosmology · Physics 2017-05-31 Andronikos Paliathanasis , John D. Barrow , Supriya Pan

A variation of fundamental constants of physics is proposed in a frame of static universe. It is shown when the velocity of light increases (decreases) the Planck's constant increases (decreases) and mass of bodies decreases (increases).…

Astrophysics · Physics 2007-05-23 V. Jonauskas

The current understanding of structure formation in the early universe is mainly built on a magnification of quantum fluctuations in an initial vacuum state during an early phase of accelerated universe expansion. One usually describes this…

Astrophysics · Physics 2008-08-06 Martin Bojowald , Aureliano Skirzewski

We present the results of two empirical constancies: the fine structure constant and the Rydberg constant. When the speed of light c is taken away from the fine structure constant, as shown elsewhere, this constancy implies the constancy of…

General Physics · Physics 2009-09-30 Antonio Alfonso-Faus

Equilibrium is a rather ideal situation, the exception rather than the rule in Nature. Whenever the external or internal parameters of a physical system are varied its subsequent relaxation to equilibrium may be either impossible or take…

Statistical Mechanics · Physics 2016-10-04 Leticia F. Cugliandolo

We introduce a class of singular partial differential equations, the second-order hyperbolic Fuchsian systems, and we investigate the associated initial value problem when data are imposed on the singularity. First of all, we analyze a…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Florian Beyer , Philippe G. LeFloch

We propose that the Universe created from "nothing" with relatively small particles number and quickly relaxed to quasiequilibrium state at the Planck parameters. The classic cosmological solution for this Universe with Lambda-term has two…

General Relativity and Quantum Cosmology · Physics 2009-12-30 V. Burdyuzha , O. Lalakulich , Yu. Ponomarev , G. Vereshkov

The backbone of nonequilibrium thermodynamics is the stability structure, where entropy is related to a Lyapunov function of thermodynamic equilibrium. Stability is the background of natural selection: unstable systems are temporary, and…

Physics and Society · Physics 2024-10-01 Peter Ván

We proved that the uncertainty relation fits in with many-particle system and the equality of the relation corresponds to the thermodynamic equilibrium state, the inequality of the relation corresponds to the thermodynamic non-equilibrium…

Quantum Physics · Physics 2007-05-23 You-gang Feng

The existence and stability of the Einstein static solution have been built in the Einstein-Cartan gravity. We show that this solution in the presence of perfect fluid with spin density satisfying the Weyssenhoff restriction is cyclically…

General Relativity and Quantum Cosmology · Physics 2014-06-11 K. Atazadeh

The cosmological constant problem is studied in a two component cosmological model. The universe contains a cosmological constant of an arbitrary size and sign and an additional component with an inhomogeneous equation of state. It is shown…

General Relativity and Quantum Cosmology · Physics 2009-01-16 Hrvoje Stefancic

In this thesis the cosmological constant is investigated from two points of view. First, we study the influence of a time-dependent cosmological constant on the late-time expansion of the universe. Thereby, we consider several combinations…

High Energy Physics - Theory · Physics 2007-05-23 Florian Bauer

This letter explores how a reinterpretation of the generalized uncertainty principle as an effective variation of Planck's constant provides a physical explanation for a number of fundamental quantities and couplings. In this context, a…

General Physics · Physics 2024-09-02 Ahmed Farag Ali , Jonas Mureika , Elias C. Vagenas , Ibrahim Elmashad

A scenario of an emergent universe is constructed in the background of an inhomogeneous space-time model which is asymptotically (at spatial infinity) FRW space-time. The cosmic substratum consists of non-interacting two components, namely…

General Relativity and Quantum Cosmology · Physics 2016-01-18 Subhra Bhattacharya , S. Chakraborty

Quantum theory, general relativity, the standard model of particle physics, and the $\Lambda$CDM model of cosmology have all been spectacularly successful within their respective regimes of applicability, but many central problems remain…

General Physics · Physics 2026-05-26 Roland E. Allen

The backreaction of structure formation influences the cosmological evolution equation for the homogenous and isotropic average metric. In a cold dark matter universe this effect leads only to small corrections unless a substantial fraction…

Astrophysics · Physics 2009-11-07 C. Wetterich

The energy composition of the Universe, as emerged from the Type Ia supernova observations and the WMAP data, looks preposterously complex, -- but only at the first glance. In fact, its structure proves to be simple and regular. An analysis…

Astrophysics · Physics 2009-11-10 Arthur Chernin

The Cosmological Principle states that the universe is both homogeneous and isotropic. This, alone, is not enough to specify the global geometry of the spacetime. If we were able to measure both the Hubble constant and the energy density we…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Edward Malec , Niall Ó Murchadha

There is increasing evidence that the universe may have a small cosmological constant. We suggest a scheme for naturally generating a small cosmological constant. Our idea requires the presence of a discrete accidental symmetry which is…

High Energy Physics - Phenomenology · Physics 2015-06-25 W. D. Garretson , E. D. Carlson

Till now, the foundation of quantum physics is still mysterious. To explore the mysteries in the foundation of quantum physics, people always take it for granted that quantum processes must be some types of fields/objects on a rigid space.…

General Physics · Physics 2025-10-24 Su-Peng Kou