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Related papers: Mimetic Compact Stars

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A specific Horndeski scalar-gravity mimetic model is investigated within a FLWR space-time. The mimetic scalar field is implemented via a Lagrangian multiplier, and it is shown that the model has equations of motion formally similar to the…

General Relativity and Quantum Cosmology · Physics 2016-03-23 Yevgeniya Rabochaya , Sergio Zerbini

Although general relativistic cosmological solutions, even in the presence of pressure, can be mimicked by using neo-Newtonian hydrodynamics, it is not clear whether there exists the same Newtonian correspondence for spherical static…

General Relativity and Quantum Cosmology · Physics 2015-06-23 A. M. Oliveira , H. E. S. Velten , J. C. Fabris , I. G. Salako

We study electrically charged compact stars in the framework of extended theory of gravity (ETG). We assume that the charge density is proportional to the energy density. The polytropic equation of state is chosen to describe the state of…

General Relativity and Quantum Cosmology · Physics 2022-08-03 Houda Mansour , Bahia Si Lakhal , Abdelkader Yanallah

We study the first cosmological implications of the mimetic theory of massive gravity recently proposed by Chamseddine and Mukhanov. This is a novel theory of ghost-free massive gravity which additionally contains a mimetic dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-03 Adam R. Solomon , Valeri Vardanyan , Yashar Akrami

We investigate the physical properties of quark stars with two different equations of state in generalized hybrid metric-Palatini gravity. This theory corresponds to a bi-scalar gravitational theory in which there are two…

General Relativity and Quantum Cosmology · Physics 2024-10-15 R. Aliannejadi , Z. Haghani

We present a covariant description of non-vacuum static spherically symmetric spacetimes in $f(R)$ gravity applying the (1+1+2) covariant formalism. The propagation equations are then used to derive a covariant and dimensionless form of the…

General Relativity and Quantum Cosmology · Physics 2025-04-07 Mariam Campbell , Sante Carloni , Peter K. S. Dunsby , Nolene F. Naidu

The phenomenon of quantum vacuum polarization in the presence of a gravitational field is well understood and is expected to have a physical reality, but studies of its back-reaction on the dynamics of spacetime are practically non-existent…

General Relativity and Quantum Cosmology · Physics 2018-02-08 Raúl Carballo-Rubio

In a series of articles we describe a novel class of geometrical models of relativistic stars. Our approach to the static spherically symmetric solutions of Einstein equations is based on a careful physical analysis of radial gauge…

Astrophysics · Physics 2007-05-23 P. P. Fiziev

We present a detailed investigation of the dynamical behavior of mimetic gravity with a general potential for the mimetic scalar field. Performing a phase-space and stability analysis, we show that the scenario at hand can successfully…

General Relativity and Quantum Cosmology · Physics 2018-12-13 Jibitesh Dutta , Wompherdeiki Khyllep , Emmanuel N. Saridakis , Nicola Tamanini , Sunny Vagnozzi

We review the current status and prospects for the conformal invariant fourth order theory of gravity which has recently been advanced by Mannheim and Kazanas as a candidate alternative to the standard second order Einstein theory. We…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Philip D. Mannheim

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 present the first interior solutions representing compact stars in $\kappa(\mathcal{R},\mathcal{T})$ gravity, by solving the modified field equations in isotropic coordinates. Further, we have assumed the metric potentials in…

General Relativity and Quantum Cosmology · Physics 2022-12-02 Ginés R. Pérez Teruel , Ksh. Newton Singh , Farook Rahaman , Tanmoy Chowdhury

The macroscopic properties of compact stars in modified gravity theories can be significantly different from the general relativistic (GR) predictions. Within the gravitational context of scalar-tensor theories, with a scalar field $\phi$…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , Sergio B. Duarte , José D. V. Arbañil

This paper explores the theoretical implications of quantum gravity by analyzing compact stellar objects, presenting three distinct models that serve as alternatives to traditional black holes. These models are characterized by their…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Salvatore Samuele Sirletti , Piero Nicolini , Mariafelicia De Laurentis

Current study highlights the physical characteristics of charged anisotropic compact stars by exploring some exact solutions of modified field equations in $f(R,G)$ gravity. A comprehensive analysis is performed from the obtained solutions…

General Relativity and Quantum Cosmology · Physics 2018-06-13 M. Farasat Shamir , Saeeda Zia

In this paper, we developed three analytical models and obtained a new class of solutions describing compact stellar structures using the theory of teleparallel gravity. We consider the general anisotropic nature of stellar configurations…

General Relativity and Quantum Cosmology · Physics 2022-09-21 Jay Solanki , Rohan Joshi , Malay Garg

The present work is to introduce a new kind of modified gravitational theory, named as $f(\mathcal{R,G,T})$ (also $f(\mathcal{R,T,G})$) gravity, where $\mathcal{R}$ is the Ricci scalar, $\mathcal{G}$ is Gauss-Bonnet invariant and…

General Relativity and Quantum Cosmology · Physics 2021-11-16 M. Ilyas

General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role…

High Energy Astrophysical Phenomena · Physics 2017-03-02 K. Yavuz Ekşi

Neutron stars are highly compact astrophysical objects and therefore of utmost relevance to learn about theories of gravity. Whereas the proper equation of state of the nuclear matter inside neutron stars is not yet known, and a wide range…

General Relativity and Quantum Cosmology · Physics 2022-04-28 Jutta Kunz

As an alternative gravity model we consider an extended Einstein-Maxwell gravity containing a gauge invariance property. Extension is assumed to be addition of a directional coupling between spatial electromagnetic fields with the Ricci…

General Relativity and Quantum Cosmology · Physics 2024-01-08 Hossein Ghaffarnejad , Leyla Naderi
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