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相关论文: Kantowski-Sachs and Bianchi III dynamics in $f\lef…

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We investigate the evolution of cosmological anisotropies within the framework of $f\left(G\right)$-gravity. Specifically, we consider a locally rotationally symmetric geometry in four-dimensional spacetime that describes the Bianchi I,…

广义相对论与量子宇宙学 · 物理学 2025-12-25 R. Bogadi , A. Giacomini , M. Govender , C. Hansraj , G. Leon , A. Paliathanasis

We construct general anisotropic cosmological scenarios governed by an $f(R)$ gravitational sector. Focusing then on Kantowski-Sachs geometries in the case of $R^n$-gravity, and modelling the matter content as a perfect fluid, we perform a…

广义相对论与量子宇宙学 · 物理学 2011-08-19 Genly Leon , Emmanuel N. Saridakis

We investigate the existence of anisotropic self-similar exact solutions in symmetric teleparallel $f\left( Q\right)$-theory. For the background geometry we consider the Kantowski-Sachs and the Locally Rotationally Symmetric Bianchi type…

广义相对论与量子宇宙学 · 物理学 2023-08-29 N. Dimakis , M. Roumeliotis , A. Paliathanasis , T. Christodoulakis

In the context of modified tele-parallel theory of gravity, we undertake cosmological anisotropic models and search for their solutions. Within a suitable choice of non-diagonal tetrads, the decoupled equations of motion are obtained for…

广义相对论与量子宇宙学 · 物理学 2015-06-25 M. E. Rodrigues , A. V. Kpadonou , F. Rahaman , P. J. Oliveira , M. J. S. Houndjo

In the context of the modified teleparallel $f(T, B)$-theory of gravity, we consider a homogeneous and anisotropic background geometry described by the Kantowski-Sachs line element. We derive the field equations and investigate the…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Genly Leon , Andronikos Paliathanasis

Considering the Universe as a dynamic system, the understanding of its evolution is an interesting aspect of study in cosmology. Here, we investigate the anisotropic locally rotationally symmetric (LRS) Bianchi type-I (LRS-BI) spacetime…

广义相对论与量子宇宙学 · 物理学 2024-06-21 Pranjal Sarmah , Umananda Dev Goswami

We investigate the existence of minisuperspace description for the homogeneous cosmological field equations within the framework of symmetric teleparallel $f(Q)$-gravity. We consider the background space to be described by the isotropic…

广义相对论与量子宇宙学 · 物理学 2023-12-19 A. Paliathanasis , N. Dimakis , T. Christodoulakis

Despite having the somewhat successful description of accelerated cosmology, the early evolution of the universe always challenges mankind. Our promising approach lies in a new class of symmetric teleparallel theory of gravity named $f(Q)$,…

广义相对论与量子宇宙学 · 物理学 2022-01-25 Avik De , Sanjay Mandal , J. T. Beh , Tee-How Loo , P. K. Sahoo

We study the asymptotic dynamics of $f(T, B)$-theory in an anisotropic Bianchi III background geometry. We show that an attractor always exists for the field equations, which depends on a free parameter provided by the specific $f(T, B)$…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Genly Leon , Andronikos Paliathanasis

In the context of scalar-torsion theory we investigate the evolution of the cosmological anisotropies for a Kantowski-Sachs background geometry. We study the phase-space of the gravitational field equations by determining the admitted…

广义相对论与量子宇宙学 · 物理学 2023-03-29 Andronikos Paliathanasis

The cosmological principle asserts that on sufficiently large scales the Universe is homogeneous and isotropic on spatial slices. To deviate from this principle requires a departure from the FLRW ansatz. In this paper we analyze the…

宇宙学与河外天体物理 · 物理学 2023-11-23 Andrei Constantin , Thomas R. Harvey , Sebastian von Hausegger , Andre Lukas

That is the first part of a series of studies on analyzing the higher-order teleparallel theory of gravity known as the $f(T, B)$-theory. This work attempts to understand how the anisotropic spacetimes are involved in the $f(T, B)$-theory.…

广义相对论与量子宇宙学 · 物理学 2022-07-19 Andronikos Paliathanasis

The one-loop renormalized effective potentials for the massive $\phi^4$ theory on the spatially homogeneous models of Bianchi type I and Kantowski-Sachs type are evaluated. It is used to see how the quantum field affects the cosmological…

广义相对论与量子宇宙学 · 物理学 2011-01-27 Wung-Hong Huang

We perform a detailed dynamical analysis of anisotropic scalar-field cosmologies, and in particular of the most significant Kantowski-Sachs, Locally Rotationally Symmetric (LRS) Bianchi I and LRS Bianchi III cases. We follow the new and…

广义相对论与量子宇宙学 · 物理学 2014-03-18 Carlos R. Fadragas , Genly Leon , Emmanuel N. Saridakis

Despite having a reasonably successful account of accelerated cosmology, understanding the early evolution of Universe has always been difficult for mankind. Our promising strategy is based on a novel class of symmetric teleparallel…

广义相对论与量子宇宙学 · 物理学 2022-09-12 L. Anjana Devi , S. Surendra Singh , Leishingam Kumrah , Md Khurshid Alam

Following recent considerations of a non-zero value for the vacuum energy density and the realization that a simple Kantowski-Sachs model might fit the classical tests of cosmology, we study the qualitative behavior of three anisotropic and…

天体物理学 · 物理学 2011-04-15 Paulo Aguiar , Paulo Crawford

This article describes the theory of cosmological perturbations around a homogeneous and anisotropic universe of the Bianchi I type. Starting from a general parameterisation of the perturbed spacetime a la Bardeen, a complete set of gauge…

天体物理学 · 物理学 2008-11-26 Thiago S. Pereira , Cyril Pitrou , Jean-Philippe Uzan

The fundamental theory and the semiclassical description of loop quantum cosmology (LQC) have been studied in the Friedmann-Robertson-Walker and Bianchi I models. As an extension to include both anisotropy and intrinsic curvature, this…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Dah-Wei Chiou

We perform dynamical analysis of anisotropic Rastall cosmologies and, in particular Kantowski-Sachs, locally rotationally symmetric (LRS) Bianchi I and LRS Bianchi III cosmologies. Using dynamical system techniques, a qualitative analysis…

广义相对论与量子宇宙学 · 物理学 2023-02-01 Ashutosh Singh , Anirudh Pradhan

We investigate the cosmological reconstruction in anisotropic universe for both homogeneous and inhomogeneous content of the universe. Special attention is attached to three interesting cases: Bianchi type-I, Bianchi type-III and…

广义相对论与量子宇宙学 · 物理学 2012-11-29 M. E. Rodrigues , M. J. S. Houndjo , D. Saez-Gomez , F. Rahaman
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