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Using recently developed nonrelativistic numerical simulation code, we investigate the stability properties of compact astrophysical objects that may be formed due to the Bose-Einstein condensation of dark matter. Once the temperature of a…

High Energy Physics - Phenomenology · Physics 2015-03-05 Eniko J. M. Madarassy , Viktor T. Toth

Compact stars consisting of massless quark matter and fermionic dark matter are studied by solving the Tolman-Oppenheimer-Volkoff equations for two fluids separately. Dark matter is further investigated by incorporating inter-fermionic…

High Energy Astrophysical Phenomena · Physics 2016-04-27 Payel Mukhopadhyay , Juregen Schaffner-Bielich

Bound states of complex scalar fields (boson stars) have long been proposed as possible candidates for the dark matter in the universe. Considerable work has already been done to study various aspects of boson stars. In the present work,…

General Relativity and Quantum Cosmology · Physics 2008-12-19 R. Sharma , S. Karmakar , S. Mukherjee

The presence of dark matter (DM) within neutron stars (NSs) can be introduced by different accumulation scenarios in which DM and baryonic matter (BM) may interact only through the gravitational force. In this work, we consider asymmetric…

High Energy Astrophysical Phenomena · Physics 2024-03-05 Davood Rafiei Karkevandi , Mahboubeh Shahrbaf , Soroush Shakeri , Stefan Typel

The so-called Buchdahl limit is not yet fully understood in the context of theories of gravity beyond the Einsteinian framework. In this investigation, we generalize this limit for the case of static, spherically-symmetric, relativistic…

General Relativity and Quantum Cosmology · Physics 2025-04-14 Raul Carpio Fernandez , Alvaro de la Cruz-Dombriz

We study the structure of neutron stars in f(R) gravity theories with perturbative constraints. We derive the modified Tolman-Oppenheimer-Volkov equations and solve them for a polytropic equation of state. We investigate the resulting…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Alan Cooney , Simon DeDeo , Dimitrios Psaltis

This work studies the formation and growth of boson stars and their surrounding miniclusters by gravitational condensation using non-linear dynamical numerical methods. Fully dynamical attractive and repulsive self-interactions are also…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-27 Jiajun Chen , Xiaolong Du , Erik W. Lentz , David J. E. Marsh , Jens C. Niemeyer

Quartic gravity theory is considered with the Einstein-Hilbert Lagrangean $R+aR^{2}+bR_{\mu \nu}R^{\mu \nu},$ $R_{\mu \nu}$ being Ricci\'s tensor and R the curvature scalar. The parameters $a$ and $b$ are taken of order 1 km$^{2}.$…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Emilio Santos

This paper presents the study of dark-energy compact stars in the context of modified Rastall teleparallel gravity. It is the first time that dark energy celestial phenomena have been explored in this modified gravitational theory.…

General Relativity and Quantum Cosmology · Physics 2025-07-03 Allah Ditta , Xia Tiecheng , G. Mustafa , Değer Sofuoğlu , Asif Mahmood

Neutron stars with strong magnetic fields are considered in the framework of f(R) gravity. In order to describe dense matter in magnetic field, the model with baryon octet interacting through $\sigma$$\rho$$\omega$-fields is used. The…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Artyom V. Astashenok , Salvatore Capozziello , Sergei D. Odintsov

In our current best cosmological model, the vast majority of matter in the Universe is dark, consisting of yet undetected, non-baryonic particles that do not interact electro-magnetically. So far, the only significant evidence for dark…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-09 Jenny Wagner

We study strange stars in the framework of $f\left(R,\mathcal{T}\right)$ theory of gravity where the strange quark matter distribution inside the stellar system is governed by the phenomenological MIT Bag model equation of state (EOS).…

General Physics · Physics 2018-04-24 Debabrata Deb , Farook Rahaman , Saibal Ray , B. K. Guha

Astronomers have been using the measured luminosity to estimate the {\em luminous mass} of stars, based on empirically established mass-to-light ratio which seems to be only applicable to a special class of stars---the main-sequence…

Astrophysics of Galaxies · Physics 2016-08-23 James Q. Feng , C. F. Gallo

The physically realistic model of compact stars undergoing gravitational collapse in $ f(R) $ gravity has been developed. We consider a more general model $ R + f(R) = R + k R^m $ and describe the interior space-time of gravitationally…

General Relativity and Quantum Cosmology · Physics 2022-05-17 Jay Solanki

The missing gravity in galaxies requires dark matter, or alternatively a modification of gravity or inertia. These theoretical possibilities of fundamental importance may be distinguished by the statistical relation between the observed…

Astrophysics of Galaxies · Physics 2022-12-21 Kyu-Hyun Chae

Modified gravity theories can introduce modifications to the Poisson equation in the Newtonian limit. As a result, we expect to see interesting features of these modifications inside stellar objects. White dwarf stars are one of the most…

General Relativity and Quantum Cosmology · Physics 2017-10-06 Srimanta Banerjee , Swapnil Shankar , Tejinder P. Singh

Millisecond pulsars, representing the older neutron star population, are believed to have undergone a prolonged period of dark matter accumulation, resulting in a higher dark matter content. Their extreme rotation makes them unique…

High Energy Astrophysical Phenomena · Physics 2025-06-27 Lorenzo Cipriani , Edoardo Giangrandi , Violetta Sagun , Daniela D. Doneva , Stoytcho S. Yazadjiev

Cold Dark Stars made of self-gravitating fermions in the degenerate limit are constructed in General Relativity and in R-square gravity, $f(R)=R+\alpha R^2$. The properties of the resulting Cold Dark Stars in both theories of gravity are…

General Relativity and Quantum Cosmology · Physics 2020-11-11 Armando A. Roque , J. Barranco

We investigate a compact star in the general $F(R)$ gravity. Developing a novel formulation in the spherically symmetric and static space-time with the matter, we confirm that an arbitrary relation between the mass $M$ and the radius $R_s$…

General Relativity and Quantum Cosmology · Physics 2022-10-18 Kota Numajiri , Taishi Katsuragawa , Shin'ichi Nojiri

The unknown physical nature of the Dark Energy motivates in cosmology the study of modifications of the gravity theory at large distances. One of these types of modifications is to consider gravity theories, generally termed as $f(R)$. In…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-07 Pedro Bessa , Marcela Campista , Armando Bernui