English
Related papers

Related papers: Dynamical Shortcomings in the Generalized SU(2) Pr…

200 papers

The dynamical aspect of accelerating cosmological model has been studied in this paper in the context of modified symmetric teleparallel gravity, the $f(Q)$ gravity. Initially, we have derived the dynamical parameters for two well known…

General Relativity and Quantum Cosmology · Physics 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

We investigate the features of the cosmological expansion history described by a recent model of gravity characterised by two nonlocally interacting metrics. We perform a detailed analysis of the dynamical system formed by the field…

General Relativity and Quantum Cosmology · Physics 2019-05-09 Leonardo Giani , Tays Miranda , Oliver F. Piattella

The dynamics of any spherical cosmology with a scalar field (`scalaron') coupling to gravity is described by the nonlinear second-order differential equations for two metric functions and the scalaron depending on the `time' parameter. The…

High Energy Physics - Theory · Physics 2017-04-05 A. T. Filippov

The cosmological dynamics of a quintessence model based on real gas with general equation of state is presented within the framework of a three-dimensional dynamical system describing the time evolution of the number density, the Hubble…

General Relativity and Quantum Cosmology · Physics 2019-02-05 Rossen I. Ivanov , Emil M. Prodanov

The physical instability of the Universe model with de Sitter beginning is proved in this article. 1. It is shown that even a small addition of ultrarelativistic matter turns the de Sitter Universe into the Universe with finite past. 2.…

General Relativity and Quantum Cosmology · Physics 2015-08-24 Yurii Ignat'ev

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

The current accelerating phase of the evolution of the universe is considered by constructing most economical cosmic models that use just general relativity and some dominating quantum effects associated with the probabilistic description…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pedro F. González-Díaz , Alberto Rozas-Fernández

We here investigate bulk-viscosity driven quasi de-Sitter inflation, that is, the period of accelerated expansion in the early universe during which $-\dot{H}\ll H^2$, with $H(t)$ being the Hubble expansion rate. We do so in the framework…

General Relativity and Quantum Cosmology · Physics 2024-02-21 Sayantani Lahiri , Luciano Rezzolla

There is mounting observational evidence that the expansion of our Universe is undergoing a late-time acceleration. Among many proposals to describe this phenomenon, the cosmological constant seems to be the simplest and the most natural…

Astrophysics · Physics 2010-03-19 S. Carneiro , C. Pigozzo , H. A. Borges , J. S. Alcaniz

A dynamical resolution to the cosmological constant fine-tuning problem has been previously put forward, based on a scalar-tensor gravitational theory possessing de Sitter attractor solutions characterized by a small Hubble expansion rate,…

General Relativity and Quantum Cosmology · Physics 2021-08-19 Oleg Evnin , Victor Massart , Kevin Nguyen

We study the cosmological evolution of isotropic matter on an infinitely thin conical codimension-two brane-world. Our analysis is based on the boundary dynamics of a six-dimensional model in the presence of an induced gravity term on the…

High Energy Physics - Theory · Physics 2009-11-11 Eleftherios Papantonopoulos , Antonios Papazoglou

Hubble constant($H_0$) tension and tension in the matter fluctuation amplitude ($s_8$) are fascinating puzzles in cosmology nowadays. Phantom dynamical dark energy model (PDDE), also known as little sibling of the big rip is an abrupt event…

General Relativity and Quantum Cosmology · Physics 2023-08-08 Naseeba. K. M , Sarath Nelleri , Navaneeth Poonthottathil

Viable models of modified gravity which satisfy both local as well as cosmological tests are investigated. It is demonstrated that some versions of such highly non-linear models exhibit multiply de Sitter universe solutions, which often…

General Relativity and Quantum Cosmology · Physics 2009-02-20 G. Cognola , E. Elizalde , S. D. Odintsov , P. Tretyakov , S. Zerbini

Hegselmann--Krause models are localized, distributed averaging dynamics on spatial data. A key aspect of these dynamics is that they lead to cluster formation, which has important applications in geographic information systems, dynamic…

Physics and Society · Physics 2025-08-14 Partha S. Dey , S. Rasoul Etesami , Aditya S. Gopalan

We derive all single-field cosmologies with unit sound speed that generate scale invariant curvature perturbations on a dynamical attractor background. We identify three distinct phases: slow-roll inflation; a slowly contracting adiabatic…

High Energy Physics - Theory · Physics 2011-08-08 Justin Khoury , Godfrey E. J. Miller

We introduce a time-delay function in bulk viscosity cosmology. Even for bulk viscosity functions where closed-form solutions are known, because of the time-delay term the exact solutions are lost. Therefore in order to study the…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Andronikos Paliathanasis

We study cosmological phase transitions from modified equations of motion by introducing two non-commutative parameters in the Poisson brackets, which describes the initial- and future-singularity-free phase transition in the soluble…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Wontae Kim , Edwin J. Son

We study the dynamics of homogeneous and isotropic Friedmann-Lema\^itre-Robertson-Walker cosmological models with positive spatial curvature within the context of mimetic gravity theory by employing dynamical system techniques. Our analysis…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Alberto Fritis , Daniel Villalobos-Silva , Yerko Vásquez , Carlos H. López-Caraballo , Juan Carlos Helo

Main aim of this work is to give a suitable explanation of present accelerating universe through an acceptable interactive dynamical cosmological model. A three-fluid cosmological model is introduced in the background of…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Giridhari Deogharia , Mayukh Bandyopadhyay , Ritabrata Biswas

We propose a novel cosmological scenario with the space-time emerging from a pure initial de Sitter stage and subsequently evolving into the radiation, matter and dark energy dominated epochs, thereby avoiding the initial singularity and…

General Relativity and Quantum Cosmology · Physics 2015-06-11 J. A. S. Lima , S. Basilakos , Joan Sola