English
Related papers

Related papers: $R^2$-gravity quark stars from perturbative QCD

200 papers

We explore the stellar structure and radial stability of charged quark stars composed of interacting quark matter (IQM) in three classes of commonly used charge models. We adopt a general parametrization of IQM equation of state that…

High Energy Astrophysical Phenomena · Physics 2021-12-28 Chen Zhang , Michael Gammon , Robert B. Mann

We investigate the effect of a strong magnetic field on the structure of neutron stars in a model with perturbative $f(R)$ gravity. The effect of an interior strong magnetic field of about $10^{17 \sim 18}$ G on the equation of state is…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Myung-Ki Cheoun , Cemsinan Deliduman , Can Güngör , Vildan Keleş , C. Y. Ryu , Toshitaka Kajino , Grant J. Mathews

In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in $R$-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas , Kalin V. Staykov

For almost twenty years the effects of a nonzero strange quark mass on the equation of state of cold and dense QCD were considered to be negligible, thereby yielding only minor corrections to the mass-radius diagram of compact stars. By…

High Energy Physics - Phenomenology · Physics 2009-11-11 Eduardo S. Fraga

We perform an O(alpha_s^2) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical…

High Energy Physics - Phenomenology · Physics 2010-06-22 Aleksi Kurkela , Paul Romatschke , Aleksi Vuorinen

Strange quark matter in beta equilibrium at high densities is studied in a quark confinement model. Two equations of state are dynamically generated for the {\it same} set of model parameters used to describe the nucleon: one corresponds to…

Astrophysics · Physics 2008-11-26 M. Malheiro , M. Fiolhais , A. R. Taurines

The structure and stability of quark stars (QSs) made of interacting quark matter are discussed in this study, taking color superconductivity and perturbative QCD corrections into account. By combining this EoS with the…

High Energy Physics - Theory · Physics 2025-06-12 Takol Tangphati , İzzet Sakallı , Ayan Banerjee , Anirudh Pradhan

We find some exact solutions for constant-density and quark matter equations of state in stellar structure models framed within the $f(R,T)=R+\lambda \kappa^2 T$ theory of gravity, where $R$ is the curvature scalar, $T$ the trace of the…

General Relativity and Quantum Cosmology · Physics 2025-04-09 Aliya Batool , Abdul Malik Sultan , Gonzalo J. Olmo , Diego Rubiera-Garcia

In this work, we study the effects that interacting quark matter has on the stellar structure of strange and charm quark stars. Additionally, their stability against radial pulsations is analyzed using a first-order formalism for adiabatic…

High Energy Physics - Phenomenology · Physics 2021-04-09 José C. Jiménez

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 the impact of $f(R,L_m,T)$ gravity on the internal structure of compact stars, expecting this theory to manifest prominently in the high-density cores of such stars. In this study, we begin by considering the algebraic…

General Relativity and Quantum Cosmology · Physics 2024-12-05 Takol Tangphati , Izzet Sakalli , Ayan Banerjee , Anirudh Pradhan

Neutron star models in perturbative $f(R)$ gravity are considered with realistic equations of state. In particular, we consider the FPS, SLy and other equations of state and a case of piecewise equation of state for stars with quark cores.…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Artyom V. Astashenok , Salvatore Capozziello , Sergei D. Odintsov

It depends on the state of matter at supra-nuclear density to model pulsar's structure, which is unfortunately not certain due to the difficulties in physics. In cold quark matter at realistic baryon densities of compact stars (with an…

Solar and Stellar Astrophysics · Physics 2009-12-08 X. Y. Lai

Assuming static and spherically symmetric stars with perfect fluid matter, we used realistic equations of state to study neutron stars in covariant $f(Q)$ gravity. The structure profiles and properties of neutron stars such as mass, radius…

General Relativity and Quantum Cosmology · Physics 2024-09-05 Muhammad Azzam Alwan , Tomohiro Inagaki , B. Mishra , S. A. Narawade

This paper gives an brief overview of the structure of hypothetical strange quarks stars (quark stars, for short), which are made of absolutely stable 3-flavor strange quark matter. Such objects can be either bare or enveloped in thin…

Solar and Stellar Astrophysics · Physics 2015-06-11 Fridolin Weber , Milva Orsaria , Hilario Rodrigues , Shu-Hua Yang

We investigate the linear regime of f(R) = R + alpha R^2 gravity for static, spherically symmetric and asymptotically flat configurations of matter. We show that, in vacuum and deep inside the range of the extra scalar degree of freedom,…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Fulvio Sbisà , Oliver F. Piattella , Sergio E. Jorás

We study solutions of the stellar structure equations for spherically symmetric objects in Palatini $f(R)=R+\alpha R^2$ and $f(R,Q)=R+\alpha R^2+\beta Q$ in the mass-radius region associated to neutron stars. We illustrate the potential…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Georg Herzog , Hèlios Sanchis-Alepuz

We investigate the properties of non-rotating, electrically charged strange quark stars in four-dimensional Einstein-Maxwell theory. For quark matter we adopt the well-motivated quantum chromodynamics (QCD) equation-of-state, while for the…

General Relativity and Quantum Cosmology · Physics 2022-05-04 Grigoris Panotopoulos , Takol Tangphati , Ayan Banerjee

We explore protoneutron star matter in the framework of cold and dense QCD using the state-of-the-art perturbative equation of state including neutrinos fixed by a lepton fraction that is appropriate for this environment. Furthermore, we…

High Energy Physics - Phenomenology · Physics 2018-07-10 J. C. Jiménez , E. S. Fraga

We consider a modified gravity theory, $f(R)=R+\alpha R^n-\frac{\mu^4}{R^m}$, in the metric formulation and analyze the contribution of electromagnetic field on the range of dynamical instability of a star filled with anisotropic matter.…

General Physics · Physics 2015-10-22 H. Rizwana Kausar , Ifra Noureen , M. Umair Shahzad