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Dynamical aspects of cosmological model in an extended gravity theory have been investigated in the present work. We have adopted a simplified approach to obtain cosmic features, which in fact requires more involved calculations. A…

广义相对论与量子宇宙学 · 物理学 2021-06-10 B. Mishra , S. K. Tripathy , Sankarsan Tarai

In this paper, we have investigated some accelerating cosmological models at the backdrop of an anisotropic metric in an extended gravity theory. Two viable cosmological models one with a little rip behaviour and the other with a hyperbolic…

广义相对论与量子宇宙学 · 物理学 2020-09-23 B. Mishra , S. K. Tripathy

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…

广义相对论与量子宇宙学 · 物理学 2023-07-18 S. A. Narawade , Shashank P. Singh , B. Mishra

Motivated by the fact that cosmological models based on $f(Q)$ gravity are very efficient in fitting observational datasets at both background and perturbation levels, we perform a combined dynamical system analysis of both background and…

广义相对论与量子宇宙学 · 物理学 2023-02-22 Wompherdeiki Khyllep , Jibitesh Dutta , Emmanuel N. Saridakis , Kuralay Yesmakhanova

The role of an exponential function of the scalar curvature in the modified gravity is analyzed. Two models are proposed. A toy model that complies with local and cosmological constraints and gives appropriate qualitative description of the…

广义相对论与量子宇宙学 · 物理学 2020-07-15 L. N. Granda

We present a detailed investigation of the cosmological dynamics based on $\exp (-R/{\Lambda})$ gravity. We apply the dynamical system approach to both the vacuum and matter cases and obtain exact solutions and their stability in the finite…

广义相对论与量子宇宙学 · 物理学 2008-11-26 M. Abdelwahab , S Carloni , P K. S. Dunsby

Alternative cosmological models have been under deep scrutiny in recent years, aiming to address the main shortcomings of the $\Lambda$CDM model. Moreover, as the accuracy of cosmological surveys improved, new tensions have risen between…

宇宙学与河外天体物理 · 物理学 2023-01-05 Filippo Bouchè , Salvatore Capozziello , Vincenzo Salzano

This paper highlights cosmologically viable sine and cosine hyperbolic evolution functions in the framework of $f(Q,\mathcal{L}_m)$ gravity. The models have been tested to check the behavior of the equation of state (EoS) parameter under…

广义相对论与量子宇宙学 · 物理学 2026-02-02 V. A. Kshirsagar , S. A. Kadam , Vishwajeet S. Goswami

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

广义相对论与量子宇宙学 · 物理学 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

This thesis investigates late-time cosmic acceleration using modified gravity theories with a focus on $f(Q)$ gravity, as an alternative to the $\Lambda$CDM model. The standard cosmological model attributes the acceleration to a…

广义相对论与量子宇宙学 · 物理学 2025-12-18 S. A. Narawade

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…

广义相对论与量子宇宙学 · 物理学 2024-09-18 Alberto Fritis , Daniel Villalobos-Silva , Yerko Vásquez , Carlos H. López-Caraballo , Juan Carlos Helo

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Ivan R. Vasquez , A. Oliveros

Inspired by an exponential $f(R)$ gravity model studied in the literature, in this work we introduce a new and viable $f(Q)$ gravity model, which can be represented as a perturbation of $\Lambda$CDM. Typically, within the realm of $f(Q)$…

宇宙学与河外天体物理 · 物理学 2024-01-31 A. Oliveros , Mario A. Acero

A new cosmological model based on the de Sitter gravity is investigated by dynamical analysis and numerical discussions. Via some transformations, the evolution equations of this model can form an autonomous system with 8 physical critical…

宇宙学与河外天体物理 · 物理学 2011-11-01 Xi-chen Ao , Xin-zhou Li , Ping Xi

In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…

广义相对论与量子宇宙学 · 物理学 2024-09-27 S. A. Kadam , Jackson Levi Said , B. Mishra

We investigate a class of scalar field dark energy models non-minimally coupled to gravity, characterized by a double exponential potential and parameterized coupling $\xi$. We study the cosmological dynamics for a recently proposed…

广义相对论与量子宇宙学 · 物理学 2025-10-28 Yerlan Myrzakulov , Saddam Hussain , Mohd Shahalam

Homogeneous isotropic spatial flat cosmological models with two torsion functions in vacuum are built and investigated in the framework of de Sitter gauge theory of gravity. It is shown that by certain choices of parameters of gravitational…

广义相对论与量子宇宙学 · 物理学 2011-10-18 Guo-Ying Qi

In this work, we consider three different $f(Q)$ models, such as power-law, exponential, and logarithmic, to study which model better mimics $\Lambda$CDM evolution theoretically. Henceforth, we determine solutions to the $f(Q)$ gravity…

广义相对论与量子宇宙学 · 物理学 2024-05-10 Gaurav N. Gadbail , P. K. Sahoo

In this work, we have considered a minimally modified gravity theory that effectively reproduces VCDM-like behavior to investigate its cosmological implications. The model parameters are constrained using a combination of CC, RSD, DESI BAO…

宇宙学与河外天体物理 · 物理学 2026-03-31 Sai Swagat Mishra , Soumya Kanta Bhoi , P. K. Sahoo

This thesis explores the cosmological implications of modified gravity, focusing on nonmetricity-based $f(Q)$ gravity as an alternative to the $\Lambda$CDM model in explaining cosmic acceleration. Chapter I lays the theoretical groundwork…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Gaurav N. Gadbail
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