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Related papers: Theoretical results on the Universe structure

200 papers

Even if the luminosity distance as a function of redshift is obtained accurately using, for example, Type Ia supernovae, the equation of state of the Universe cannot be determined uniquely but depends on one free parameter $\Omega_{k0}…

Astrophysics · Physics 2009-10-31 Takashi Nakamura , Takeshi Chiba

We review and develop the classical theory of moments of configurations of weighted points with a focus on systems with an identically vanishing first moment. The latter condition produces equations for equilibrium configurations of systems…

Mathematical Physics · Physics 2026-03-06 Eduardo S. G. Leandro

In light of G\"{o}del's undecidability results (incomplete theorems) for math, quantum indeterminism indicates that physics and the Universe may be indeterministic, incomplete, and open in nature, and therefore demand no single unification…

General Physics · Physics 2020-03-11 Wanpeng Tan

We investigate a class of cosmological solutions of Einstein's field equations in higher dimensions with a cosmological constant and an ideal fluid matter distribution as a source. We discuss the dynamical evolution of the universe subject…

General Relativity and Quantum Cosmology · Physics 2013-02-15 Ozgur Akarsu , Tekin Dereli

Alternative forms of the solutions to the quantum field equations and their implications for physical theory are considered. Incorporation of these alternative solution forms, herein deemed "supplemental solutions", into the development of…

General Physics · Physics 2019-03-05 Robert D. Klauber

Apparently, all partial differential equations that describe physical phenomena in space-time can be cast into a universal quasilinear, first-order form. In this paper, we do two things. First, we describe some broad features of systems of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert Geroch

Motivated by the notion that the mathematics of gravity can be reproduced from a statistical requirement of maximal entropy, we study the consequence of introducing an entropic source term in the Einstein-Hilbert action. For a spatially…

General Relativity and Quantum Cosmology · Physics 2024-03-20 Soumya Chakrabarti

Given a functional for a one-dimensional physical system, a classical problem is to minimize it by finding stationary solutions and then checking the positive definiteness of the second variation. Establishing the positive definiteness is,…

Classical Analysis and ODEs · Mathematics 2017-04-26 Thomas Lessinnes , Alain Goriely

Assuming that universe is the object of point rotation at a frequency, the relationship is established between this frequency and the cosmological constant. Using the transformation for point-like rotating coordinate systems, an unusual…

General Physics · Physics 2018-07-25 Boris V. Gisin

We discuss cosmological models for an eternal universe. Physical observables show no singularity from the infinite past to the infinite future. While the universe is evolving, there is no beginning and no end - the universe exists forever.…

General Relativity and Quantum Cosmology · Physics 2014-08-27 C. Wetterich

We generalize the well-known Bonnor-Melvin solution of the Einstein-Maxwell equations to the case of a non-vanishing cosmological constant. The spacetime is again cylindrically symmetric and static but, unlike the original solution, it…

General Relativity and Quantum Cosmology · Physics 2019-03-21 Martin Zofka

The state space of a homogeneous body is derived under two different assumptions: infinitesimal reducibility and irreducibility. The first assumption leads to a real vector space, used in classical mechanics, while the second one leads to a…

Quantum Physics · Physics 2012-03-19 Gabriele Carcassi

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…

Astrophysics · Physics 2007-05-23 Norbert Straumann

Old and new puzzles of cosmology are reexamined from the point of view of quantum theory of the universe developed here. It is shown that in proposed approach the difficulties of the standard cosmology do not arise. The theory predicts the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. E. Kuzmichev , V. V. Kuzmichev

The possibility of an emergent universe solution to Einstein's field equations allowing for an irreversible creation of matter at the expense of the gravitational field is shown. With the universe being chosen as spatially flat FRW…

General Relativity and Quantum Cosmology · Physics 2016-09-27 Sunandan Gangopadhyay , Anirban Saha , S. Mukherjee

The idea of the quantum state of the Universe described by some density matrix, i.e mixture of at least two vacua, the trivial symmetric and the nontrivial one with spontaneously broken symmetry is discussed. Nonzero cosmological constant…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. A. Grib

Time-symmetric cosmological theories, in which the initial and final states are arranged to have similar features or are independently fixed, have been quite extensively discussed in the literature. However, a more general and perhaps more…

General Relativity and Quantum Cosmology · Physics 2012-04-20 Adrian Kent

The universe is found to have undergone several phases in which the gravitational constant had different behaviors. During some epochs the energy density of the universe remained constant and the universe remained static. In the radiation…

Astrophysics · Physics 2007-05-23 Arbab I. Arbab

A stationary line element of general relativity seems to be compatible to essential cosmological facts (though only as far as one can expect solving the nonlinear Einstein equations neglecting local cosmic evolution and all spatial…

General Physics · Physics 2007-05-23 Peter Ostermann

In this letter, by regarding finite-time stability as an inverse problem, we reveal the essence of finite-time stability and fixed-time stability. Some necessary and sufficient conditions are given. As application, we give a new approach…

Adaptation and Self-Organizing Systems · Physics 2016-02-19 Wenlian Lu , Xiwei Liu , Tianping Chen