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We propose a new doorway to study the interplay between equations of state of dense matter and compact stars in gauge/gravity correspondence. For this we construct a bulk geometry near the boundary of five-dimensional spacetime. By solving…

High Energy Physics - Phenomenology · Physics 2015-06-05 Kyung Kiu Kim , Youngman Kim , Ik Jae Shin

Charged stars have the potential of becoming charged black holes or even naked singularities. It is presented a set of numerical solutions of the Tolman-Oppenheimer-Volkov equations that represents spherical charged compact stars in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Cristian R. Ghezzi

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

We generalize the Tolman-Oppenheimer-Volkoff equations for space-times endowed with a Weyssenhoff like torsion field in the Einstein-Cartan theory. The new set of structure equations clearly show how the presence of torsion affects the…

General Relativity and Quantum Cosmology · Physics 2019-10-18 Paulo Luz , Sante Carloni

The kinetic motion of the stars of a galaxy is considered within the framework of a relativistic scalar theory of gravitation. This model, even though unphysical, may represent a good laboratory where to study in a rigorous, mathematical…

Mathematical Physics · Physics 2017-08-23 Simone Calogero

The stability of the recently proposed static solutions for boson stars is analyzed. These solutions of Einstein-Klein-Gordon (EKG) equations arise from considering the interaction of a real scalar field with matter. We assume that the…

General Relativity and Quantum Cosmology · Physics 2021-01-14 D. S. Fontanella , A. Cabo

We study the effect of electric charge in compact stars assuming that the charge distribution is proportional to the mass density. The pressure and the density of the matter inside the stars are large, and the gravitational field is…

Using a variation of the celebrated Volkov solution, the Klein-Gordon equation for a charged particle is reduced to a set of ordinary differential equations, exactly solvable in specific cases. The new quantum relativistic structures can…

Plasma Physics · Physics 2017-12-18 Fernando Haas , Marcos Antonio Albarracin Manrique

Topological stars are regular, horizonless solitons arising from dimensional compactification of Einstein-Maxwell theory in five dimensions, which could describe qualitative properties of microstate geometries for astrophysical black holes.…

General Relativity and Quantum Cosmology · Physics 2025-02-10 Alexandru Dima , Marco Melis , Paolo Pani

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

This is a review of some recent developments on quantum gravity aspects of black hole physics. In particular, we focus on a scenario leading to the prediction of the existence of a Planck-mass quasi-stable object, that could form a…

General Relativity and Quantum Cosmology · Physics 2024-09-10 Carlo Rovelli , Francesca Vidotto

We construct spherically symmetric solutions to the Einstein-Euler equations, which contains a positive cosmological constant, say, the Einstein-Euler-de Sitter equations. We assume a realistic barotropic equation of state. Equilibria of…

Analysis of PDEs · Mathematics 2019-06-11 Tetu Makino

We study spherically symmetric static solutions to the semi-classical Einstein equation sourced by the vacuum energy of quantum fields in the curved space-time of the same solution. We found solutions that are small deformations of the…

High Energy Physics - Theory · Physics 2018-03-14 Pei-Ming Ho , Yoshinori Matsuo

We consider static spherically symmetric stellar configurations in Palatini theories of gravity in which the Lagrangian is an unspecified function of the form f(R,R_{\mu\nu}R^{\mu\nu}). We obtain the Tolman-Oppenheimer-Volkov equations…

General Relativity and Quantum Cosmology · Physics 2012-11-06 Gonzalo J. Olmo , Helios Sanchis-Alepuz , Swapnil Tripathi

We consider plane-symmetric spacetimes satisfying Einstein's field equations with positive cosmological constant, when the matter is a fluid whose pressure is equal to its mass-energy density (i.e. a so-called stiff fluid). We study the…

General Relativity and Quantum Cosmology · Physics 2012-05-01 Philippe G. LeFloch , Sophonie B. Tchapnda

We solve the Tolman-Oppenheimer-Volkoff equation using an equation of state (EoS) calculated in holographic QCD. The aim is to use compact astrophysical objects like neutron stars as an indicator to test holographic equations of state. We…

High Energy Physics - Phenomenology · Physics 2015-05-30 Youngman Kim , Chang-Hwan Lee , Ik Jae Shin , Mew-Bing Wan

This study investigates the topological implications arising from stable (free boundary) minimal surfaces in a static perfect fluid space while ensuring that the fluid satisfies certain energy conditions. Based on the main findings, it has…

Differential Geometry · Mathematics 2023-11-30 Maria Andrade , Benedito Leandro , Thamara Policarpo

The trace-free Einstein equations contain one equation less than the complete field equations. In a static and spherically symmetric spacetime, the number of field equations is thus reduced to two. The equation of pressure isotropy of…

General Relativity and Quantum Cosmology · Physics 2024-03-27 Sudan Hansraj , Chevarra Hansraj , Njabulo Mkhize , Abdelghani Errehymy , Christian G. Boehmer

We investigate the geodesic structure of realistic static and spherically symmetric spacetimes embedding neutron stars in metric $f(R)$ gravity, focusing on the quadratic Starobinsky model $f(R)=aR^2$ with $a<0$. Neutron-star solutions are…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Néstor Rivero González , Álvaro de la Cruz Dombriz , Gonzalo J. Olmo

Dark stars are compact massive objects, described by Einstein gravitational field equations with matter. The type we consider possesses no event horizon, instead, there is a deep gravitational well with a very strong redshift factor.…

Astrophysics of Galaxies · Physics 2021-02-17 Igor Nikitin