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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

In this work we study the magnitude-redshift relation of a non-standard cosmological model. The model under consideration was firstly investigated within a special case of metric-affine gravity (MAG) and was recently recovered via different…

General Relativity and Quantum Cosmology · Physics 2009-04-03 Dirk Puetzfeld , Xuelei Chen

We extend the geometrical ideas of the spacetime deformations to study the physical foundation of the post-Riemannian geometry. To this aim, we construct the theory of 'two-step spacetime deformation' as a guiding principle. We address the…

General Relativity and Quantum Cosmology · Physics 2011-04-05 G Ter-Kazarian

We find numerical solutions of the coupled system of Einstein-Maxwell's equations with a linear approach, in which the magnetic field acts as a perturbation of a spherical neutron star. In our study, magnetic fields having both poloidal and…

Astrophysics · Physics 2009-11-13 A. Colaiuda , V. Ferrari , L. Gualtieri , J. A. Pons

In this manuscript, we investigate the possibility of constructing anisotropic dark matter compact stars motivated by the Einasto density profile. This work develops analytical solutions for an anisotropic fluid sphere within the framework…

General Relativity and Quantum Cosmology · Physics 2024-10-03 Z. Yousaf , Kazuharu Bamba , Bander Almutairi , Yuki Hashimoto , S. Khan

Motivation: Motivated by the growing interest in understanding the role of non-metricity in describing dense stellar systems, in this paper, we study compact stellar configurations within the framework of linear $f(Q)$ gravity. Methodology:…

General Relativity and Quantum Cosmology · Physics 2026-04-28 Arpita Ghosh , Abhishek Paul , Ranjan Sharma , Samstuti Chanda

Pronounced core-halo patterns of dark matter and gas density profiles, observed in relaxed galaxies and clusters, were hitherto fitted by empirical power-laws. On the other hand, similar features are well known from astrophysical plasma…

Astrophysics · Physics 2009-11-11 M. P. Leubner

It is often expected that one cannot treat spacetime as a continuous manifold as the Planck scale is approached, because of to possible effects due to a quantum theory of gravity. There have been several proposals to model such a deviation…

General Relativity and Quantum Cosmology · Physics 2023-01-23 Andrea Bevilacqua

We show that there is a direct relation between upper limits on (or potential future measurements of) the m = 2 quadrupole moments of slowly rotating neutron stars and the l = m = 2 deformation of the star's surface, in full general…

Solar and Stellar Astrophysics · Physics 2014-04-29 Nathan K. Johnson-McDaniel

The equation of state of dense matter determines the structure of neutron stars, their typical radii, and maximum masses. Recent improvements in theoretical modeling of nuclear forces from the low-energy effective field theory of QCD has…

Nuclear Theory · Physics 2019-09-04 Jeremy W. Holt , Yeunhwan Lim

The effects of phase space deformations on Kalutza-Klein cosmology are studied. The deformation is introduced by modifying the symplectic structure of the minisuperspace variables. In the deformed model, we find an accelerating scale factor…

General Relativity and Quantum Cosmology · Physics 2016-03-30 M. Sabido , C. Yee-Romero

Recent work showed that $\kappa$-deformations can describe the quantum deformation of several relativistic models that have been proposed in the context of quantum gravity phenomenology. Starting from the Poincar\'e algebra of…

General Relativity and Quantum Cosmology · Physics 2022-02-01 Angel Ballesteros , Giulia Gubitosi , Flavio Mercati

We construct dark energy stars with Chaplygin-type equation of state (EoS) in the presence of anisotropic pressure within the framework of Einstein gravity. From the classification established by Iyer et al. [Class. Quantum Grav. 2, 219…

General Relativity and Quantum Cosmology · Physics 2023-01-18 Juan M. Z. Pretel

We consider a non-minimally coupled Einstein-Maxwell gravity with no $U(1)$ symmetry property to study stability of an electrostatic star via canonical quantization approach and obtain that the stability is free of gauge field effects. By…

General Relativity and Quantum Cosmology · Physics 2023-06-21 Hossein Ghaffarnejad

We study relativistic stars in degenerate higher-order scalar-tensor theories that evade the constraint on the speed of gravitational waves imposed by GW170817. It is shown that the exterior metric is given by the usual Schwarzschild…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Tsutomu Kobayashi , Takashi Hiramatsu

This article is devoted to the study of new exact analytical solutions in the background of Reissner-Nordstr\"{o}m space-time by using gravitational decoupling via minimal geometric deformation approach. To do so, we impose the most general…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Angel Rincon , Luciano Gabbanelli , Ernesto Contreras , Francisco Tello-Ortiz

We use a modified Einstein-Maxwell gravity to study stability of an electrostatic spherical star. Correction terms in this model are scalers which are made from contraction of Ricci tensor and electromagnetic vector potential. Our…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Hossein Ghaffarnejad , Tohid Ghorbani , Firoozeh Eidizadeh

We use data from observational cosmology to put constraints on higher-dimensional extensions of general relativity in which the effective four-dimensional dark-energy density (or cosmological "constant") decays with time. In particular we…

Astrophysics · Physics 2009-11-13 J. M. Overduin , P. S. Wesson , B. Mashhoon

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

Neutron star matter spans a wide range of densities, from that of nuclei at the surface to exceeding several times normal nuclear matter density in the core. While terrestrial experiments, such as nuclear or heavy-ion collision experiments,…

High Energy Astrophysical Phenomena · Physics 2023-12-19 Suprovo Ghosh , Debarati Chatterjee , Jürgen Schaffner-Bielich