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Related papers: Anisotropic quantum polytropes

200 papers

The effects of the cosmological constant on the static equilibrium configurations and stability against small radial perturbations of relativistic polytropic spheres are investigated. This study numerically solves the hydrostatic…

General Relativity and Quantum Cosmology · Physics 2020-04-15 José D. V. Arbañil , Pedro H. R. S. Moraes

Spherically symmetric equilibrium configurations of perfect fluid obeying a polytropic equation of state are studied in spacetimes with a repulsive cosmological constant. The configurations are specified in terms of three parameters---the…

General Relativity and Quantum Cosmology · Physics 2016-11-17 Zdeněk Stuchlík , Stanislav Hledík , Jan Novotný

This manuscript examines viability and stability of anisotropic compact objects in the framework of $f(Q,L_m)$ gravity ($Q$ is the non-metricity and $L_m$ is the matter Lagrangian). We assume a particular functional form of this theory to…

General Relativity and Quantum Cosmology · Physics 2026-05-05 M. Sharif , M. Zeeshan Gul , Adeeba Arooj

We investigate anisotropic compact stars comprising two non-interacting fluids: quark matter and condensed dark matter. Using the MIT Bag model equation of state for quark matter and Bose-Einstein Condensate equation of state for dark…

General Relativity and Quantum Cosmology · Physics 2025-05-28 G. Panotopoulos , A. Rincón , I. Lopes

Particle physics candidates for cosmological dark matter are usually considered as neutral and weakly interacting. However stable charged leptons and quarks can also exist and, hidden in elusive atoms, play the role of dark matter. The…

Astrophysics · Physics 2008-01-03 M. Yu. Khlopov

We introduce a new type of generating theorems in General Relativity for anisotropic, static, spherically symmetric solutions of the Einstein field equations. The results are used to derive a class of solutions that can serve as new models…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Paulo Luz , Sante Carloni

Ultra-light axion-like particle (ULAP) with mass $m \sim 10^{-22} ~\mathrm{eV}$ has recently been attracting attention as a possible solution to the small-scale crisis. ULAP forms quasi-stable objects called oscillons/I-balls, which can…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Masahiro Kawasaki , Kazuyoshi Miyazaki , Kai Murai , Hiromasa Nakatsuka , Eisuke Sonomoto

Dense quantum plasmas are ubiquitous in planetary interiors and in compact astrophysical objects, in semiconductors and micro-mechanical systems, as well as in the next generation intense laser-solid density plasma interaction experiments…

Plasma Physics · Physics 2015-05-13 Padma K. Shukla , Bengt Eliasson

We obtain well behaved interior solutions describing hydrostatic equilibrium of anisotropic relativistic stars in scale-dependent gravity, where Newton's constant is allowed to vary with the radial coordinate throughout the star. Assuming…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Grigoris Panotopoulos , Angel Rincon , Ilidio Lopes

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

General Relativity and Quantum Cosmology · Physics 2012-06-18 Suresh Kumar , Ozgur Akarsu

We consider the possibility that the dark matter, which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic center, could be in the form of a Bose-Einstein condensate. To study the…

Astrophysics · Physics 2010-10-27 C. G. Boehmer , T. Harko

We investigate the impact of pressure anisotropy on the structural and geometric properties of neutron stars within general relativity, focusing primarily on the phenomenological Bowers-Liang (BL) model, and comparing selected results with…

General Relativity and Quantum Cosmology · Physics 2026-05-08 A. C. Khunt , K. Yavuz Ekşi , P. C. Vinodkumar

The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original…

High Energy Astrophysical Phenomena · Physics 2017-06-30 José D. V. Arbañil , M. Malheiro

The behavior near the initial singular state of the anisotropy parameter of the arbitrary type, homogeneous and anisotropic Bianchi models is considered in the framework of the brane world cosmological models. The matter content on the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 T. Harko , M. K. Mak

We propose a relativistic model for quintessence stars with the combination of an anisotropic pressure corresponding to normal matter and a quintessence dark energy having a characteristic parameter {\omega}q such that -1 <{\omega}q < -…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Mehedi Kalam , Farook Rahaman , Sajahan Molla , Sk. Monowar Hossein

We consider a trapped quasi2D dipolar Bose Einstein condensate (q2D DBEC) with a polariza- tion tilted into the plane of motion. We show that by tilting the polarization axis, the coherence properties are anisotropic. Such a system will…

Atomic Physics · Physics 2012-11-06 Christopher Ticknor

New phenomenological models of Quantum Gravity have suggested that a Lorentz-Invariant discrete spacetime structure may become manifest through a nonstandard coupling of matter fields and spacetime curvature. On the other hand, there is…

General Relativity and Quantum Cosmology · Physics 2013-02-13 Mario A. Acero , Yuri Bonder

We address the equilibrium configurations and stability properties of anisotropic compact stars whose interior is described by a modified Chaplygin gas (MCG) equation of state in the framework of the regularized four-dimensional…

General Relativity and Quantum Cosmology · Physics 2025-11-13 Anirudh Pradhan , Takol Tangphati , Ayan Banerjee , Javlon Rayimbaev

Recent observations of Type Ia supernova at high redshifts establish that the dark energy component of the universe has (a probably constant) ratio between pressure and energy density $w=p/\rho=-1.02(^{+0.13}_{-0.19})$. The conventional…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Edgard Gunzig , Alberto Saa

Two distinct non-singular interior models that describe anisotropic spherical configurations are presented in this work. We develop the Einstein field equations and the associated mass function in accordance with a static spherical…

General Relativity and Quantum Cosmology · Physics 2025-10-10 M. Sharif , Tayyab Naseer , Hira Shadab