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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…

广义相对论与量子宇宙学 · 物理学 2009-11-19 Jakub Mielczarek , Orest Hrycyna , Marek Szydlowski

Isotropic and spatially homogeneous viscous fluid cosmological models are investigated using the truncated Israel-Stewart theory of irreversible thermodynamics to model the bulk viscous pressure. The governing system of differential…

广义相对论与量子宇宙学 · 物理学 2010-04-06 A A Coley , R J van den Hoogen

In this paper, a bouncing cosmological scenario is studied in the background of a flat FLRW model with a specific parametrized hyperbolic form of scale factor $ a $ in terms of $ t $, where $ \lambda $ is taken as the model parameter. This…

广义相对论与量子宇宙学 · 物理学 2022-08-12 J. K. Singh , Shaily , Kazuharu Bamba

Modern cosmological theory is based on the Friedmann--Robertson--Walker (FRW) metric. Often written in terms of co-moving coordinates, this well-known solution to Einstein's equations owes its elegant and highly practical formulation to the…

综合物理 · 物理学 2018-09-14 Fulvio Melia

Cosmological features of Barrow Holographic Dark Energy (BHDE), a recent generalization of original Holographic dark energy with a richer structure, are studied in the context of DGP brane, RS II brane-world, and the cyclic universe. It is…

广义相对论与量子宇宙学 · 物理学 2024-01-23 Anirban Chanda , Arpan Krishna Mitra , Souvik Ghose , Sagar Dey , Bikash Chandra Paul

The challenge of understanding the Universe's dynamics, particularly the Hubble tension, requires precise measurements of the Hubble constant. Building upon the existing spectral-siren method, which capitalizes on population information…

广义相对论与量子宇宙学 · 物理学 2025-01-10 Thomas C. K. Ng , Stefano Rinaldi , Otto A. Hannuksela

The dynamical evolution of the scale factor of FRW cosmological model is presented, when the equation of state of the material content assume the form $\rm p=\gamma \rho$, $\rm \gamma=constant$, including the cosmological term. We use the…

广义相对论与量子宇宙学 · 物理学 2007-05-23 S. R. Berbena , A. V. Berrocal , J. Socorro , Luis O. Pimentel

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological…

广义相对论与量子宇宙学 · 物理学 2019-02-11 Nasr Ahmed , Sultan Z. Alamri

We present a systematic analysis of the dynamics of flat Friedmann-Lema\^{i}tre-Robertson-Walker cosmological models with radiation and dust matter in generalized teleparallel $f(T)$ gravity. We show that the cosmological dynamics of this…

广义相对论与量子宇宙学 · 物理学 2017-09-05 Manuel Hohmann , Laur Jarv , Ulbossyn Ualikhanova

Usually, we assume that there is no inhomogeneity isotropic in terms of our location in our uni- verse. This assumption has not been observationally confirmed yet in sufficient accuracy, and we need to consider the possibility that there…

宇宙学与河外天体物理 · 物理学 2017-03-06 Hiroyuki Negishi , Ken-ichi Nakao

The cosmological dynamics are rigorously investigated through the systematic application of autonomous system analysis to the gravitational field equations in non-metricity gravity. The systematic procedure to analyze the late-time cosmic…

广义相对论与量子宇宙学 · 物理学 2025-03-13 Pooja Vishwakarma , Parth Shah , Kazuharu Bamba

We reverse the logic behind the apparent existence of $H_0$-tension, to design diagnostics for cosmological models. The basic idea is that the non-constancy of $H_0$ inferred from observations at different redshifts is a null hypothesis…

宇宙学与河外天体物理 · 物理学 2022-02-01 Chethan Krishnan , Ranjini Mondol

In this paper we exploit the theory of the dynamical systems to study the dynamics of the standard cosmological model of the universe, which is known as the $\Lambda$CDM model. We assume that the matter content in our universe consists of…

综合物理 · 物理学 2022-09-07 Danijela Branković , Žarko Mijajlović

Flat FRW perfect fluid cosmologies can be reproduced as particular solutions of suitable field theoretical models. Here we investigate the stability of perfect fluid model trajectories with respect to sets of trajectories of the…

The phases as well as the amplitudes of baryonic acoustic oscillations can be extracted out of a galaxy power spectrum and used as a standard ruler in a cosmological test. A non-oscillating phenomenological fitting function is used to…

天体物理学 · 物理学 2009-11-11 Ralf S. Koehler , Peter Schuecker , Karl Gebhardt

This paper has studied five-dimensional FRW cosmological models for k=-1,0,1in the presence of two perfect fluids namely ordinary baryonic fluid and a bizarre creating dark energy within the framework of Lyra's manifold (Lyra 1951). We have…

广义相对论与量子宇宙学 · 物理学 2023-12-22 Syed Sabanam , Kangujam Priyokumar Singh

In this paper we study cosmological solutions of the $f(T,B)$ gravity using dynamical system analyses. For this purpose we consider cosmological viable functions of $f(T,B)$ that are capable of reproducing the dynamics of the Universe. We…

广义相对论与量子宇宙学 · 物理学 2020-07-31 Geovanny A. Rave Franco , Celia Escamilla-Rivera , Jackson Levi Said

We propose a new dynamical system formalism for the analysis of f(R) cosmologies. The new approach eliminates the need for cumbersome inversions to close the dynamical system and allows the analysis of the phase space of f(R)-gravity models…

广义相对论与量子宇宙学 · 物理学 2015-10-27 Sante Carloni

We study a Newtonian cosmological model in the context of a noncommutative space. It is shown that the trajectories of a test particle undergo modifications such that it no longer satisfies the cosmological principle. For the case of a…

高能物理 - 理论 · 物理学 2010-11-05 Juan M. Romero , J. A. Santiago

The limits imposed by the classical cosmological tests on closed and open FRW universes driven by adiabatic matter creation are investigated. Exact expressions for the lookback time, age of the universe, luminosity distance, angular…

天体物理学 · 物理学 2011-05-23 J. S. Alcaniz , J. A. S. Lima
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