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Related papers: On radial anisotropy limits in stellar systems

200 papers

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the…

General Relativity and Quantum Cosmology · Physics 2017-10-04 T. Harko , M. K. Mak

This paper is an investigation of the stability of some ideal stars. It is in- tended as a study in General Relativity, with emphasis on the coupling to matter, eventually aimed at a better understanding of very strong gravitational fields…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian Fronsdal

We investigate the dynamical evolution of isolated equal-mass star cluster models by means of direct N-body simulations, primarily focusing on the effects of the presence of primordial anisotropy in the velocity space. We found evidence of…

Astrophysics of Galaxies · Physics 2017-08-16 Philip G. Breen , Anna Lisa Varri , Douglas C. Heggie

We built two self-consistent models of triaxial, cuspy, rotating stellar systems adding rotation to non-rotating models presented in previous papers of this series. The final angular velocity of the material is not constant and varies with…

Astrophysics of Galaxies · Physics 2016-04-20 D. D. Carpintero , J. C. Muzzio

We analyze the velocity anisotropy of stars in real and energy space for a sample of Milky Way-like galaxies in the TNG50 simulation. We employ different selection criteria, including spatial, kinematic and metallicity cuts, and make three…

We present new results on instabilities in rapidly and differentially rotating neutron stars. We model the stars in full general relativity and describe the stellar matter adopting a cold realistic equation of state based on the unified SLy…

General Relativity and Quantum Cosmology · Physics 2010-06-01 Giovanni Corvino , Luciano Rezzolla , Sebastiano Bernuzzi , Roberto De Pietri , Bruno Giacomazzo

A recent paper (Martinez--Gonzalez & Sanz 1995) showed that if the universe is homogeneous but anisotropic, then the small quadrupole anisotropy in the cosmic microwave background radiation implies that the spacetime anisotropy is very…

Astrophysics · Physics 2007-05-23 Roy Maartens , George Ellis , William Stoeger

We have proposed a model for relativistic compact star with anisotropy and analytically obtained exact spherically symmetric solutions describing the interior of the dense star admitting non-static conformal symmetry. Several features of…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Dibyendu Shee , Farook Rahaman , B. K. Guha , Saibal Ray

We study the oscillations and stability of self-gravitating cylindrically symmetric fluid systems and collisionless systems. This is done by studying small perturbations to the equilibrium system and finding the normal modes, using methods…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-15 Patrick C. Breysse , Marc Kamionkowski , Andrew Benson

Anisotropic stresses are ubiquitous in nature, but their modeling in General Relativity is poorly understood and frame dependent. We introduce the first study on the dynamical properties of anisotropic self-gravitating fluids in a covariant…

General Relativity and Quantum Cosmology · Physics 2019-06-05 Guilherme Raposo , Paolo Pani , Miguel Bezares , Carlos Palenzuela , Vitor Cardoso

We add to the lore of spherical, stellar-system models a two-parameter family with an anisotropic velocity dispersion, and a central point mass (``black hole''). The ratio of the tangential to radial dispersions, is constant--and…

Astrophysics · Physics 2009-10-28 Mordehai Milgrom

The properties of the analitycal phase--space distribution function of two-component spherical self-consistent galaxy models, where one density distribution follows the Hernquist profile, and the other a gamma=0 model, with different total…

Astrophysics · Physics 2007-05-23 L. Ciotti

(Abridged) We study the properties of anisotropic and axisymmetric velocity ellipsoids from maps of the gas velocity dispersion in nearby galaxies. This data allow us to measure the azimuthal-to-radial axis ratio of gas velocity ellipsoids,…

Astrophysics of Galaxies · Physics 2020-08-05 Laurent Chemin , Jonathan Braine , Françoise Combes , Zacharie S. Kam , Claude Carignan

High-resolution spectroscopic time series of rapidly oscillating Ap stars show evidence for a co-existence of standing and running waves in their atmospheric layers. With the purpose of understanding these observations we have carried out a…

Astrophysics · Physics 2009-06-23 J. C. Sousa , M. S. Cunha

We study a three dimensional continuous model of gravitating matter rotating at constant angular velocity. In the rotating reference frame, by a finite dimensional reduction, we prove the existence of non radial stationary solutions whose…

Analysis of PDEs · Mathematics 2012-06-08 Juan Campos Serrano , Manuel Del Pino , Jean Dolbeault

A method is presented for solving elastodynamic problems in radially inhomogeneous elastic materials with spherical anisotropy, i.e.\ materials such that $c_{ijkl}= c_{ijkl}(r)$ in a spherical coordinate system ${r,\theta,\phi}$. The time…

Materials Science · Physics 2011-12-26 A. N. Norris , A. L. Shuvalov

Under certain conditions, stellar radial velocities can be determined from astrometry, without any use of spectroscopy. This enables us to identify phenomena, other than the Doppler effect, that are displacing spectral lines. The change of…

Solar and Stellar Astrophysics · Physics 2021-08-18 Lennart Lindegren , Dainis Dravins

The detection of a dipole anisotropy in the sky distribution of sources in large-scale radio surveys can be used to constrain the magnitude and direction of our local motion with respect to an isotropically distributed extragalactic radio…

Astrophysics · Physics 2009-11-13 Fronefield Crawford

We investigate the linear tearing instability in weakly collisional plasmas using a non-ideal gyrotropic-MHD framework, uncovering a previously unknown scaling relation for the instability growth rate in high-$\beta$ environments. Even…

Plasma Physics · Physics 2025-10-09 Gabriel L. Ferreira-Santos , Grzegorz Kowal , Diego A. Falceta-Gonçalves

This paper formulates some new exact solutions to the field equations by means of minimal gravitational decoupling in the context of $f(\mathbb{R},\mathbb{T})$ gravity. For this purpose, we consider anisotropic spherical matter distribution…

General Relativity and Quantum Cosmology · Physics 2022-12-14 M. Sharif , Tayyab Naseer