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The equation of state provided by effective models of strongly interacting matter should comply with the restrictions imposed by current astrophysical observations of compact stars. Using the equation of state given by the (axial-)vector…

High Energy Physics - Phenomenology · Physics 2019-07-19 János Takátsy , Péter Kovács , Zsolt Szép , György Wolf

This paper is devoted to study the possibility of forming anisotropic compact stars in modified Gauss-Bonnet, namely called as $f(G)$ theory of gravity which is one of the strong candidates,responsible for the accelerated expansion of the…

General Relativity and Quantum Cosmology · Physics 2015-05-27 G. Abbas , D. Momeni , M. Aamir Ali , R. Myrzakulov , S. Qaisar

We address quasinormal modes of compact objects in several alternative theories of gravity. In particular, we focus on black holes and neutron stars with scalar hair. We consider black holes in dilaton-Einstein-Gau\ss -Bonnet theory, and in…

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

Based on a baryonic extended linear sigma model including explicit chiral symmetry breaking effect, the structure of neutron star with the emergence of hyperons is investigated using the relativistic mean field approximation. It's found…

Nuclear Theory · Physics 2025-12-30 Yao Ma , Yong-Liang Ma , Lu-Qi Zhang

We show that even a rather minimal extension of the Einstein - Hilbert action by a nonminimal coupling of the scalar field to the Ricci curvature scalar results in configurations that resemble more the dark energy stars then the ordinary…

General Relativity and Quantum Cosmology · Physics 2013-09-02 Dubravko Horvat , Anja Marunovic

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 the context of f(R) gravity theories, we show that the apparent mass of a neutron star as seen from an observer at infinity is numerically calculable but requires careful matching, first at the star's edge, between interior and exterior…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Miguel Aparicio Resco , Alvaro de la Cruz-Dombriz , Felipe J. Llanes-Estrada , Victor Zapatero Castrillo

We investigate the properties of high density compact objects in a vector type theory, inspired by Einstein's 1919 theory of elementary particles, in which Einstein assumed that elementary particles are held together by gravitational as…

General Relativity and Quantum Cosmology · Physics 2022-04-12 Zahra Haghani , Tiberiu Harko

A new model of charged compact star is reported by solving the Einstein-Maxwell field equations by choosing a suitable form of radial pressure. The model parameters $\rho$, $p_r$, $p_{\perp}$ and $E^{2}$ are in closed form and all are well…

General Relativity and Quantum Cosmology · Physics 2018-01-08 B. S. Ratanpal , Piyali Bhar

Physically based changes to general relativity (GR) often predict significant differences in how spacetime behaves near massive neutron stars. One of these modifications is represented by $f(\mathcal{Q}, { \mathcal{T}})$, with $\mathcal{Q}$…

General Relativity and Quantum Cosmology · Physics 2024-10-21 G. G. L. Nashed , Tiberiu Harko

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

The most recent detections of LIGO/Virgo and NICER have placed strong constraints on neutron stars' properties. In this work, we study neutron stars modeling them as hybrid stars, compact objects with a quark matter core surrounded by…

High Energy Astrophysical Phenomena · Physics 2022-03-30 Mauro Mariani , Daniela Curin , Milva G. Orsaria , Ignacio F. Ranea-Sandoval

In this paper, we study the stellar structure in terms of alternative theory of gravity specially by f (R;T) gravity theory. Here, we consider the function f (R;T) = R+2VT where R is the Ricci scalar, T is the stress-energy momentum and V…

General Relativity and Quantum Cosmology · Physics 2021-06-24 J. Kumar , H. D. Singh , A. K. Prasad

The present work discusses about the existence of compact star model in the context of $f(R,T)$ gravity with $R$ as the Ricci scalar and $T$ as the trace of energy-momentum tensor $T_{\mu \nu}$. The model has been developed by considering…

General Relativity and Quantum Cosmology · Physics 2021-07-05 Piyali Bhar , Pramit Rej , Aisha Siddiqa , Ghulam Abbas

Screening mechanisms are often deployed by dark energy models in order to conceal the effects of their new degrees of freedom from the scrutiny of terrestrial and solar system experiments. However, extreme properties of nuclear matter may…

General Relativity and Quantum Cosmology · Physics 2021-12-08 Bernardo F. de Aguiar , Raissa F. P. Mendes , F. T. Falciano

We investigate realistic models of compact objects, focusing on neutron and strange stars, composed by dense matter and dark energy in the form of a simple fluid or scalar field interacting with matter. For the dark energy component, we use…

General Relativity and Quantum Cosmology · Physics 2023-08-01 Artyom V. Astashenok , Sergey D. Odintsov , Vasilis K. Oikonomou

It is shown that the theoretical arguments for the unavoidable collapse of massive stars, which are valid within standard general relativity, are not valid in extended gravity. In particular a calculation is reported of neutron stars within…

General Relativity and Quantum Cosmology · Physics 2011-12-22 Emilio Santos

The purpose of this paper is to study charged compact stars using extended gravitational theory, also known as $f(\mathcal{R}, \mathcal{G}, \mathcal{T})$ gravity. Alternatively, this theory is also called $f(\mathcal{R}, \mathcal{T},…

General Relativity and Quantum Cosmology · Physics 2023-08-23 M. Ilyas , A. R. Athar , Asma Bibi

Modified gravity is one of the potential candidates to explain the accelerated expansion of the universe. Current study highlights the materialization of anisotropic compact stars in the context of $f(R,G)$ theory of gravity. In particular,…

General Physics · Physics 2017-07-07 M. Farasat Shamir , Saeeda Zia