English
Related papers

Related papers: How closed is cosmology?

200 papers

We perform a detailed dynamical analysis of various cosmological scenarios in extended (varying-mass) nonlinear massive gravity. Due to the enhanced freedom in choosing the involved free functions, this cosmological paradigm allows for a…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-05 Genly Leon , Joel Saavedra , Emmanuel N. Saridakis

Dynamical similarities are non-standard symmetries found in a wide range of physical systems that identify solutions related by a change of scale. In this paper we will show through a series of examples how this symmetry extends to the…

General Relativity and Quantum Cosmology · Physics 2021-07-21 David Sloan

We assume a one-to-one correspondence between comoving coordinates and the cosmic rest frame in a spherically symmetric inhomogeneous universe. This strongly restricts the solutions of Einstein's equations: (i) The pressure must be zero.…

General Physics · Physics 2018-05-29 Günter Scharf

It is often stated that a phase of standard, decelerated cosmological expansion is characterised by the absence of global event horizons, while a phase of accelerated expansion is associated with the absence of particle horizons. This is…

General Relativity and Quantum Cosmology · Physics 2026-05-14 M. Gasperini

In recent years, by theory and observation cosmology has advanced substantially. Parameters of the concordance or $\Lambda$CDM cosmological model are given with unprecedented precision ("precision cosmology"). On the other side, 95% of the…

General Relativity and Quantum Cosmology · Physics 2012-04-17 Hubert F. Goenner

On the basis of the general relativistic statistical and kinetic theory, a consistent closed cosmological model is formulated. It is based on a statistical system of scalar charged fermions interacting by means of classical and phantom…

General Relativity and Quantum Cosmology · Physics 2021-11-02 Yu. G. Ignat'ev , D. Yu. Ignatyev

We discuss implications of the cosmological frame principle which states that cosmological effects of modified gravity must be stable as solutions of each of the corresponding sets of dynamical equations holding in the two…

General Relativity and Quantum Cosmology · Physics 2023-08-23 Spiros Cotsakis , Jose P. Mimoso , John Miritzis

Cosmology of self-interacting three-forms is investigated. The minimally coupled canonical theory can naturally generate a variety of isotropic background dynamics, including scaling, possibly transient acceleration and phantom crossing. An…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Tomi S. Koivisto , Nelson J. Nunes

In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and…

General Relativity and Quantum Cosmology · Physics 2009-11-19 Jakub Mielczarek , Orest Hrycyna , Marek Szydlowski

It has recently been realized that many theories of physics beyond the Standard Model give rise to cosmological histories exhibiting extended epochs of cosmological stasis. During such epochs, the abundances of different energy components…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-17 Keith R. Dienes , Lucien Heurtier , Fei Huang , Tim M. P. Tait , Brooks Thomas

A detailed comparative qualitative analysis and numerical simulation of evolution of the cosmological models based on the doublet of classical and phantom scalar fields with self-action. The 2-dimensional and 3-dimensional projections of…

General Relativity and Quantum Cosmology · Physics 2018-10-24 Yurii Ignat'ev , Alexander Agathonov , Irina Kokh

We use the method of embedding a subsystem (i.e. its observable algebra) into a larger quantum system to extract a cosmological sector from full Loop Quantum Gravity. The application of this method provides a setting for a systematic study…

General Relativity and Quantum Cosmology · Physics 2007-11-08 Tim A. Koslowski

The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-13 Shulei Cao

A generalized scalar-tensor theory is investigated whose cosmological term depends on both a scalar field and its time derivative. A correspondence with solutions of five-dimensional Space-Time-Matter theory is noted. Analytic solutions are…

General Relativity and Quantum Cosmology · Physics 2009-11-07 T. Fukui , J. M. Overduin

A hybrid metric with off-diagonal temporal-radial behavior that was constructed to conveniently parameterized the early and late time behaviors of the universe is shown to have diagonal forms consistent with Robertson-Walker and deSitter…

General Relativity and Quantum Cosmology · Physics 2007-05-23 James Lindesay

The treatment of the principle of general covariance based on coordinate systems, i.e., on classical tensor analysis suffers from an ambiguity. A more preferable formulation of the principle is based on modern differential geometry: the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Vladimir S. Mashkevich

We describe a rigorous construction, using matched asymptotic expansions, which establishes under very general conditions that local terrestrial and solar-system experiments will measure the effects of varying `constants' of Nature…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Douglas J. Shaw , John D. Barrow

The study of the properties of cosmic structures in the universe is one of the most fascinating subject of the modern cosmology research. Far from being predicted, the large scale structure of the matter distribution is a very recent…

Statistical Mechanics · Physics 2016-11-23 L. Pietronero , M. Bottaccio , M. Montuori , F. Sylos Labini

The background dynamical evolution of a universe filled with matter and a cosmological scalar field is analyzed employing dynamical system techniques. After the phenomenology of a canonical scalar field with exponential potential is…

General Relativity and Quantum Cosmology · Physics 2014-04-23 Nicola Tamanini

We examine "dynamical similarities" in the Lagrangian framework. These are symmetries of an intrinsically determined physical system under which observables remain unaffected, but the extraneous information is changed. We establish three…

General Relativity and Quantum Cosmology · Physics 2018-07-04 David Sloan