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Related papers: $R^2$-gravity quark stars from perturbative QCD

200 papers

There is a growing interest in investigating modified theories of gravity, primarily, with the aim of explaining the universe's accelerated expansion, which has been confirmed by several independent observations. Compact objects, like…

General Relativity and Quantum Cosmology · Physics 2021-08-16 K Nobleson , Tuhin Malik , Sarmistha Banik

We construct an equation of state for massive neutron stars based on quantum chromodynamics phenomenology. Our primary purpose is to delineate the relevant ingredients of equations of state that simultaneously have the required stiffness…

High Energy Physics - Phenomenology · Physics 2015-03-05 Toru Kojo , Philip D. Powell , Yifan Song , Gordon Baym

Thermal evolution of neutron stars is studied in the $f(R)=R+\alpha R^{2}$ theory of gravity. We first describe the equations of stellar structure and evolution for a spherically symmetric spacetime plus a perfect fluid at rest. We then…

General Relativity and Quantum Cosmology · Physics 2023-06-08 Martín Nava-Callejas , Dany Page , Mikhail V. Beznogov

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

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

The effects implied for the structure of compact objects by the modification of General Relativity produced by the generalization of the Lagrangian density to the form f(R)=R+\alpha R^2, where R is the Ricci curvature scalar, have been…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-24 Mariana Orellana , Federico García , Florencia Anabella Teppa Pannia , Gustavo Esteban Romero

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

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

In this work, we investigate static configurations of dark energy stars within the framework of Rastall-Rainbow (R-R) gravity, which combines an energy-dependent deformation of spacetime with a nonminimal coupling between matter and…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Ayan Banerjee , Bobur Turimov , Sulton Usanov , Murodbek Vapaev , Yunus Turaev , Zebo Avezmuratova

Compact stars consisting of massless quark matter and fermionic dark matter are studied by solving the Tolman-Oppenheimer-Volkoff equations for two fluids separately. Dark matter is further investigated by incorporating inter-fermionic…

High Energy Astrophysical Phenomena · Physics 2016-04-27 Payel Mukhopadhyay , Juregen Schaffner-Bielich

Spherically symmetric configurations of the non-interacting massive complex scalar field, representing non-rotating boson stars, are considered within the framework of the modified torsion based $f(T)$ gravity, with $f(T) = T + \alpha \,…

General Relativity and Quantum Cosmology · Physics 2020-10-19 Saša Ilijić , Marko Sossich

A recent study shows that incorporating a new term into the thermodynamic potential density, as required by the thermodynamic consistency criterion, can effectively resolve the thermodynamic inconsistency problems of the conventional…

High Energy Physics - Phenomenology · Physics 2025-12-01 Shu-Peng Wang , Zhen-Yan Lu , Zhi-Jun Ma , Rong-Yao Yang , Jian-Feng Xu , Xiangyun Fu

We study relativistic stars in the scale-dependent scenario, which is one of the approaches to quantum gravity, and where Newton's constant is promoted to a scale-dependent quantity. First, the generalized structure equations are derived…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Grigoris Panotopoulos , Ángel Rincón , Ilídio Lopes

In this work, we investigate gravastar-like structures in static and spherically symmetric space-time within the framework of $f(Q)$ gravity coupled with conformal symmetry. We have modified the conventional gravastar model by introducing a…

General Relativity and Quantum Cosmology · Physics 2025-05-26 Debadri Bhattacharjee , Pradip Kumar Chattopadhyay

We derive a working model for the Tolman-Oppenheimer-Volkoff equation for quark star systems within the modified $f(T, \mathcal{T})$-gravity class of models. We consider $f(T, \mathcal{T})$-gravity for a static spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2017-05-08 Mark Pace , Jackson Levi Said

We study the strong gravity regime in viable models of so-called f(R) gravity that account for the observed cosmic acceleration. In contrast with recent works suggesting that very relativistic stars might not exist in these models, we find…

General Relativity and Quantum Cosmology · Physics 2014-11-18 E. Babichev , D. Langlois

In this work, we investigate the equilibrium structure of white dwarfs within the covariant formulation of symmetric teleparallel $f(Q)$ gravity, in which gravity is described by the nonmetricity scalar $Q$ instead of spacetime curvature.…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Rajasmita Sahoo

We investigate static spherically symmetric spacetimes within the framework of symmetric teleparallel $f(Q)$ gravity in order to describe relativistic stars. We adopt a specific ansatz for the background geometry corresponding to a…

General Relativity and Quantum Cosmology · Physics 2026-02-12 Nikolaos Dimakis , Alex Giacomini , Andronikos Paliathanasis , Grigorios Panotopoulos

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

General relativity can be formulated equivalently with a non-Riemannian geometry that associates with an affine connection of nonzero nonmetricity $Q$ but vanishing curvature $R$ and torsion $T$. Modification based on this description of…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Rui-Hui Lin , Xiang-Hua Zhai