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Related papers: Astrophysical Objects in Modified Theories of Grav…

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We study slowly-rotating neutron stars in ghost-free massive bigravity. This theory modifies General Relativity by introducing a second, auxiliary but dynamical tensor field that couples to matter through the physical metric tensor through…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Andrew Sullivan , Nicolas Yunes

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…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Gaurav N. Gadbail

The torsion models have stood out among the proposals for an alternative description of gravity. The simplest of them, the Teleparallel theory, is equivalent to General Relativity and there are many studies that seek to study its extension…

General Relativity and Quantum Cosmology · Physics 2022-12-09 H. G. M. Fortes , J. C. N. de Araujo

Topological structure has been extensively studied and confirmed in highly correlated condensed matter physics. We explore the gravitational waves emitted from binary neutron star mergers using the pseudoconformal model for dense nuclear…

Nuclear Theory · Physics 2021-07-07 Wen-Cong Yang , Yong-Liang Ma , Yue-Liang Wu

General Relativity (GR) is not the only way gravity can be geometrised. Instead of curvature, the Teleparallel Theory attributes gravity to torsion $T$, which is related to the antysimmetric part of connection, and the Symmetric…

General Relativity and Quantum Cosmology · Physics 2025-12-02 J. C. N de Araujo , H. G. M. Fortes

This paper's main aim is to investigate the existence of a new classification of embedded class-I solutions of compact stars, by using Karmarkar condition in $f(R)$ gravity background. To achieve that goal, we consider two different models…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Tayyaba Naz , Ammara Usman , M. Farasat Shamir

The paper presents late time cosmology in $f(Q,T)$ gravity where the dark energy is purely geometric in nature. We start by employing a well motivated $f(Q,T)$ gravity model, $f(Q,T)=mQ^{n}+bT$ where $m,n$ and $b$ are model parameters.…

General Relativity and Quantum Cosmology · Physics 2020-07-06 Simran Arora , S. K. J. Pacif , Snehasish Bhattacharjee , P. K. Sahoo

We obtain well behaved interior solutions describing hydrostatic equilibrium of anisotropic relativistic stars in scale-dependent gravity, where Newton's constant is allowed to vary with the radial coordinate throughout the star. Assuming…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Grigoris Panotopoulos , Angel Rincon , Ilidio Lopes

In this paper, we construct a viable strange star model in the framework of the equation of state, $p_r=\frac{1}{3}(\rho-4B)$, proposed in the MIT bag model, where $B$ is termed as the bag constant. Considering extreme Wood-Saxon-like…

General Relativity and Quantum Cosmology · Physics 2026-03-17 Sourav Biswas , Debadri Bhattacharjee , Pradip Kumar Chattopadhyay , Nawal H. Siddig , Euaggelos E. Zotos , Laila Abdulaziz Al-Essa

Some classical aspects of Metric-Affine Gravity are reviewed in the context of the $F^{(n)}(R)$ type models (polynomials of degree $n$ in the Riemann tensor) and the topologically massive gravity. At the non-perturbative level, we explore…

General Relativity and Quantum Cosmology · Physics 2021-05-13 Rolando Gaitan , Yessica Dominguez

In this work we present a brief discussion about modified and extended cosmological models using current observational tests. We show that according to these astrophysical samples based in late universe measurements, theories like $f(R)$…

General Relativity and Quantum Cosmology · Physics 2021-01-25 Celia Escamilla-Rivera

The main subjects of the PhD dissertation concern cosmological models considered in Palatini f(R) gravity and scalar-tensor theories. We introduce a simple generalization of the LCDM model based on Palatini modified gravity with quadratic…

General Relativity and Quantum Cosmology · Physics 2016-11-01 Aneta Wojnar

We investigate the properties of anisotropic, spherically symmetric compact stars, especially neutron stars and strange quark stars, made of strongly magnetized matter. The neutron stars are described by SLy equation of state, the strange…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Debabrata Deb , Banibrata Mukhopadhyay , Fridolin Weber

The main focus of this paper is to discuss the solutions of Einstein-Maxwell's field equations for compact stars study. We have chosen the MIT bag model equation of state for the pressure-energy density relationship and conformal Killing…

General Relativity and Quantum Cosmology · Physics 2020-11-16 M. Farasat Shamir

Within the metric formalism of $f(R,T,L_m)$ gravity theories, we investigate the hydrostatic equilibrium structure of compact stars taking into account both isotropic and anisotropic pressure. For this purpose, we focus on the $f(R,T,L_m)=…

General Relativity and Quantum Cosmology · Physics 2024-07-08 Juan M. Z. Pretel

Motivated by the dark energy issue, a minisuperspace approach to the stability for modified gravitational models in a four dimensional cosmological setting are investigated. Specifically, after revisiting the $f(R)$ case, $R$ being the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Guido Cognola , Monica Gastaldi , Sergio Zerbini

We study the impact of non-local modifications of General Relativity on stellar structure. In particular, assuming an analytic distortion function and specific equations of state, we made use of remnant stars to put qualitative constraints…

General Relativity and Quantum Cosmology · Physics 2023-01-23 Grigoris Panotopoulos , Javier Rubio , Ilídio Lopes

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Yue-Yue Zhao , Ya-Bo Wu , Jianbo Lu , Zhuo Zhang , Wei-Li Han , Liang-Liang Ling

We consider the effect of a logarithmic f(R) theory, motivated by the form of the one-loop effective action arising from gluons in curved spacetime, on the structure of relativistic stars. In addition to analysing the consistency…

General Relativity and Quantum Cosmology · Physics 2013-12-16 Hamzeh Alavirad , Joel M. Weller

We investigate a compact star in the general $F(R)$ gravity. Developing a novel formulation in the spherically symmetric and static space-time with the matter, we confirm that an arbitrary relation between the mass $M$ and the radius $R_s$…

General Relativity and Quantum Cosmology · Physics 2022-10-18 Kota Numajiri , Taishi Katsuragawa , Shin'ichi Nojiri