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Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD)…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Juan M. Z. Pretel , Takol Tangphati , Ayan Banerjee , Anirudh Pradhan

Owed to their compactness, neutron stars involve strong gravity and extreme density physics. Nevertheless, at present, there are a variety of problems where progress (at least conceptually) can be made in the context of weak gravity.…

General Relativity and Quantum Cosmology · Physics 2023-03-02 Nils Andersson , Fabian Gittins , Shanshan Yin , Rodrigo Panosso Macedo

This paper presents the study of dark-energy compact stars in the context of modified Rastall teleparallel gravity. It is the first time that dark energy celestial phenomena have been explored in this modified gravitational theory.…

General Relativity and Quantum Cosmology · Physics 2025-07-03 Allah Ditta , Xia Tiecheng , G. Mustafa , Değer Sofuoğlu , Asif Mahmood

We obtain bounds on the stability of various self-gravitating astrophysical objects using a new measure of shape complexity known as configurational entropy. We apply the method to Newtonian polytropes, neutron stars with an…

General Relativity and Quantum Cosmology · Physics 2016-07-06 Marcelo Gleiser , Nan Jiang

This paper is devoted to studying charged anisotropic static spherically symmetric solutions through gravitationally decoupled minimal geometric deformation technique in $f(R)$ gravity. For this purpose, we first consider the known…

General Relativity and Quantum Cosmology · Physics 2019-07-24 M. Sharif , Arfa Waseem

In this work, we have investigated anisotropic neutron stars in the framework of Rastall-Rainbow gravity. All our calculations were computed using the IU-FSU realistic equation of state (EoS), in which was considered two cases: standard…

High Energy Astrophysical Phenomena · Physics 2019-11-11 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Cesar V. Flores , Tiago J. N. da Silva , Débora P. Menezes

We experience some challenges in general gravitational theory owing to Einstein to explain late time acceleration of universe. To address this issue, geometric components of gravity have been modified in quite a few occasions to have a more…

General Relativity and Quantum Cosmology · Physics 2024-10-04 Santanu Das , Nilanjana Mahata , Priyanka Ray

The objective of this research is to explore compact celestial objects while considering the framework of an extended gravitational theory known as $\mathcal{R}+f(\mathcal{G})$ gravity. The notations $\mathcal{R}$ and $\mathcal{G}$ denote…

General Relativity and Quantum Cosmology · Physics 2024-07-08 G. G. L. Nashed , Kazuharu Bamba

Over the past decades, the role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description. Here we review various…

General Relativity and Quantum Cosmology · Physics 2016-09-09 Yi-Fu Cai , Salvatore Capozziello , Mariafelicia De Laurentis , Emmanuel N. Saridakis

The dynamics of metric perturbations is explored in the gravity theory with anomaly-induced quantum corrections. Our first purpose is to derive the equation for gravitational waves in this theory on the general homogeneous and isotropic…

General Relativity and Quantum Cosmology · Physics 2012-02-21 Julio C. Fabris , Ana M. Pelinson , Filipe de O. Salles , Ilya L. Shapiro

In this study we explore the astrophysical implications of pressure anisotropy on the physical characteristics of millisecond pulsars within the framework of $f(Q)$ gravity, {in particular $f(Q)=-\alpha\, Q - \beta$, where $\alpha$ and…

General Relativity and Quantum Cosmology · Physics 2024-10-08 S. K. Maurya , Ksh. Newton Singh , G. Mustafa , M. Govender , Abdelghani Errehymy , Abdul Aziz

Quasi-equilibrium models of rapidly rotating triaxially deformed stars are computed in general relativistic gravity, assuming a conformally flat spatial geometry (Isenberg-Wilson-Mathews formulation) and a polytropic equation of state.…

Astrophysics · Physics 2009-01-08 Xing Huang , Charalampos Markakis , Noriyuki Sugiyama , Koji Uryu

Within the metric formalism of $f(R)$ theories of gravity, where $R$ is the Ricci scalar, we study the hydrostatic equilibrium structure of compact stars with the inclusion of anisotropic pressure. In particular, we focus on the $f(R)=…

General Relativity and Quantum Cosmology · Physics 2022-07-11 Juan M. Z. Pretel , Sergio B. Duarte

We study relativistic stars in the context of scalar tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider…

General Relativity and Quantum Cosmology · Physics 2015-03-13 E. Babichev , D. Langlois

We investigate anisotropic compact stars in the non-minimal $Y(R)F^2$ model of gravity which couples an arbitrary function of curvature scalar $Y(R)$ to the electromagnetic field invariant $F^2$. After we obtain exact anisotropic solutions…

General Relativity and Quantum Cosmology · Physics 2018-10-17 Özcan Sert , Fatma Çeliktaş , Muzaffer Adak

It is well known that alternative theories to the Standard Model allow -- and sometimes require -- fundamental constants, such as the fine-structure constant, $\alpha$, to vary in spacetime. We demonstrate that one way to investigate these…

High Energy Physics - Phenomenology · Physics 2025-03-17 E. -A. Kolonia , C. J. A. P. Martins , Konstantinos N. Gourgouliatos

We investigate the impact of $f(R,L_m,T)$ gravity on the internal structure of compact stars, expecting this theory to manifest prominently in the high-density cores of such stars. In this study, we begin by considering the algebraic…

General Relativity and Quantum Cosmology · Physics 2024-12-05 Takol Tangphati , Izzet Sakalli , Ayan Banerjee , Anirudh Pradhan

This paper is the third in a series on tests of gravity using observations of stars and nearby dwarf galaxies. We carry out four distinct tests using published data on the kinematics and morphology of dwarf galaxies, motivated by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Vinu Vikram , Anna Cabre , Bhuvnesh Jain , Jake VanderPlas

The aim of this paper is to reconstruct and analyze the stability of some cosmological models against linear perturbations in $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ represent the Gauss-Bonnet invariant and trace of the…

General Relativity and Quantum Cosmology · Physics 2017-06-22 M. Sharif , Ayesha Ikram

This paper investigates some particular anisotropic star models in $f(\mathcal{R},\mathcal{T},\mathcal{Q})$ gravity, where $\mathcal{Q}=\mathcal{R}_{\omega\alpha}\mathcal{T}^{\omega\alpha}$. We adopt a standard model…

General Relativity and Quantum Cosmology · Physics 2023-04-05 M. Sharif , T. Naseer