English
Related papers

Related papers: Astrophysical constraints on compact objects in 4D…

200 papers

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2016-09-27 Pierre M. Pizzochero

Einstein-dilaton-Gauss-Bonnet gravity is a theoretically well-motivated alternative theory of gravity emerging as a low-energy 4-dimensional model from heterotic string theory. Its rotating black hole solutions are known numerically and can…

General Relativity and Quantum Cosmology · Physics 2017-06-01 Hao Zhang , Menglei Zhou , Cosimo Bambi , Burkhard Kleihaus , Jutta Kunz , Eugen Radu

In this work, we delve into the model of the shift symmetric and parity-preserving Beyond Horndeski theory in all its generality. We present an explicit algorithm to extract static and spherically symmetric black holes with primary scalar…

General Relativity and Quantum Cosmology · Physics 2024-07-22 Athanasios Bakopoulos , Nikos Chatzifotis , Theodoros Nakas

We present new sequences of general relativistic, quasiequilibrium black hole-neutron star binaries. We solve for the gravitational field in the conformal thin-sandwich decomposition of Einstein's field equations, coupled to the equations…

Astrophysics · Physics 2009-11-11 Keisuke Taniguchi , Thomas W. Baumgarte , Joshua A. Faber , Stuart L. Shapiro

In this paper, we study the $D\to3$ limit of Gauss-Bonnet gravity with quintessential matter, obtaining exact solutions that extend the BTZ metric through higher-curvature terms and quintessence coupling. The solutions exhibit a single…

General Relativity and Quantum Cosmology · Physics 2026-03-05 G. Alencar , T. M. Crispim , J. Macedo , C. R. Muniz

We investigate gravitational analogue models to describe slowly rotating objects (e.g., dark-matter halos, or boson stars) in terms of Bose-Einstein condensates, trapped in their own gravitational potentials. We begin with a modified…

General Relativity and Quantum Cosmology · Physics 2014-11-26 Florian Kuhnel , Cornelius Rampf

As Einstein's gravity is a non-renormalizable theory, it can be a good description of physics only at the scales of energy or spacetime curvature below the Planck mass. Moreover, it requires the presence of an infinite tower of…

General Relativity and Quantum Cosmology · Physics 2025-08-22 Ziyue Zhu , Alexey S. Koshelev , Yang Liu , Anna Tokareva

A toy model of Einstein gravity with a Gauss-Bonnet classically "entropic" term mimicking a quantum correction is considered. The static black hole solution due to Tomozawa is found and generalized with the inclusion of non trivial horizon…

General Relativity and Quantum Cosmology · Physics 2013-10-15 Guido Cognola , Ratbay Myrzakulov , Lorenzo Sebastiani , Sergio Zerbini

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

Glavan and Lin's proposal of an effective four-dimensional Einstein--Gauss--Bonnet (4D-EGB) gravity framework yields predictions that differ from general relativity in some regimes. A range of black hole studies have offered insights into…

General Relativity and Quantum Cosmology · Physics 2026-02-26 Syed Masood

As we know that the Lovelock theory is an extension of the general relativity to the higher-dimensions, in this theory the first and the second order terms correspond to the general relativity and the Einstein-Gauss-Bonnet gravity,…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Sushant G. Ghosh , Muhammed Amir , Sunil D. Maharaj

White dwarfs (WDs), as the remnants of low to intermediate-mass stars, provide a unique opportunity to explore the interplay between quantum mechanical degeneracy pressure and gravitational forces under extreme conditions. In this study, we…

General Relativity and Quantum Cosmology · Physics 2025-05-22 Juan M. Z. Pretel , Takol Tangphati , İzzet Sakallı , Ayan Banerjee

We attempt to clarify several aspects concerning the recently presented four-dimensional Einstein-Gauss-Bonnet gravity. We argue that the limiting procedure outlined in [Phys. Rev. Lett. 124, 081301 (2020)] generally involves ill-defined…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Julio Arrechea , Adrià Delhom , Alejandro Jiménez-Cano

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

This paper is devoted to the computation of compact binaries composed of one black hole and one neutron star. The objects are assumed to be on exact circular orbits. Standard 3+1 decomposition of Einstein equations is performed and the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Philippe Grandclement

In this paper, in an FLRW background and a perfect fluid equation of state, we explore the possibility of the realization of an emergent scenario in a 4D regularized extension of Einstein-Gauss-Bonnet gravity, with the field equations…

General Relativity and Quantum Cosmology · Physics 2024-06-12 Mrinnoy M. Gohain , Kalyan Bhuyan

In recent years, there has been a growing interest in stellar modelling in the framework of Einstein-Gauss-Bonnet gravity. In this paper, for a relativistic star in static equilibrium, we invoke the $5$ dimensional Einstein-Gauss-Bonnet…

General Relativity and Quantum Cosmology · Physics 2023-06-22 Soumik Bhattacharya , Suntharalingam Thirukkanesh , Ranjan Sharma

Gravitational waves emitted by distorted black holes---such as those arising from the coalescence of two neutron stars or black holes---carry not only information about the corresponding spacetime but also about the underlying theory of…

General Relativity and Quantum Cosmology · Physics 2020-11-05 Jose Luis Blázquez-Salcedo , Caio F. B. Macedo , Vitor Cardoso , Valeria Ferrari , Leonardo Gualtieri , Fech Scen Khoo , Jutta Kunz , Paolo Pani

It is shown that Einstein gravity in four dimensions with small cosmological constant and small extra dimensions can be obtained by spontaneous compactification of Lovelock gravity in vacuum. Assuming that the extra dimensions are compact…

High Energy Physics - Theory · Physics 2009-09-09 Fabrizio Canfora , Alex Giacomini , Ricardo Troncoso , Steven Willison

The existence of cosmological compact objects with very strong gravity is a prediction of General Relativity and an exact solution of the Einstein equations. These objects are called black holes and recently we had the first observations of…

General Relativity and Quantum Cosmology · Physics 2022-12-09 Ioannis Antoniou