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We study the properties of non-rotating and rotating neutron stars for a new set of equations of state (EOSs) with different high density behaviour obtained using the extended field theoretical model. The high density behaviour for these…

Nuclear Theory · Physics 2008-11-26 Shashi K. Dhiman , Raj Kumar , B. K. Agrawal

We perform three-dimensional, Newtonian hydrodynamic simulations with a nuclear equation of state to investigate the accretion dynamics in neutron star black hole systems. We find as a general result that non-spinning donor stars yield…

Astrophysics · Physics 2009-11-10 S. Rosswog , R. Speith , G. A. Wynn

We attempt to match the most general cylindrically symmetric vacuum space-time with a Robertson-Walker interior. The matching conditions show that the interior must be dust filled and that the boundary must be comoving. Further, we show…

General Relativity and Quantum Cosmology · Physics 2009-11-10 B. C. Nolan , L. V. Nolan

We investigate the evolution of non-adiabatic collapse of a shear-free spherically symmetric stellar configuration with anisotropic stresses accompanied with radial heat flux. The collapse begins from a curvature singularity with infinite…

General Relativity and Quantum Cosmology · Physics 2013-04-30 R. Sharma , R. Tikekar

We study the response of giant stars to mass loss. One-dimensional simulations of red and asymptotic giant branch stars with mass loss rates from $10^{-3}$ up to a few \msun/yr show in no case any significant radius increase. The largest…

Solar and Stellar Astrophysics · Physics 2015-06-03 Jean-Claude Passy , Falk Herwig , Bill Paxton

In this paper we study the shear free spherical symmetric gravitational collapse of charged radiating star. All the physical quantities including pressure, density are regular. Energy conditions are satisfied throughout the interior of the…

General Relativity and Quantum Cosmology · Physics 2023-12-29 Suresh C. Jaryal , Ayan Chatterjee , Akshay Kumar

We study possible static non-Schwarzschild exteriors for nonstatic spherically symmetric stars in a Randall $&$ Sundrum type II braneworld scenario. Thus, the vacuum region outside the surface of a star is assumed to be a static solution to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. Ponce de Leon

Modelling isolated rotating stars at any rotation rate is a challenge for the next generation of stellar models. These models will couple dynamical aspects of rotating stars, like angular momentum and chemicals transport, with classical…

Solar and Stellar Astrophysics · Physics 2015-06-11 Michel Rieutord , Francisco Espinosa Lara

A rotating star may be modeled as a continuous system of particles attracted to each other by gravity and with a given total mass and prescribed angular velocity. Mathematically this leads to the Euler-Poisson system. We prove an existence…

Analysis of PDEs · Mathematics 2018-04-17 Yilun Wu , Walter Strauss

Metal-free stars are assumed to evolve at constant mass because of the very low stellar winds. This leads to large CO-core mass at the end of the evolution, so primordial stars with an initial mass between 25 and 85 Msol are expected to end…

Astrophysics · Physics 2009-11-13 S. Ekström , G. Meynet , R. Hirschi , A. Maeder

We review a series of recent results on global dynamic properties of radially symmetric self-gravitating compressible Euler flows, which naturally arise in the mathematical description of stars. We focus on the role of scaling invariances…

Analysis of PDEs · Mathematics 2023-06-06 Mahir Hadzic

As the stars carry electrical charges, we present in this paper a model for charged dark energy star which is singularity free. We take Krori-Barua space time. We assume that the radial pressure exerted on the system due to the presence of…

General Physics · Physics 2015-06-19 Kanika Das , Nawsad Ali

We construct spherically symmetric boson star solutions in $D \in \{4,5,6\}$ spacetime dimensions, considering the effects of both a quartic self-interaction term and a solitonic potential. We then perform a perturbative analysis,…

General Relativity and Quantum Cosmology · Physics 2025-10-17 Gareth Arturo Marks , Abdullah Al Zaif

We show that near-horizon geometries in the presence of a positive cosmological constant cannot exist with ring topology. In particular, de Sitter black rings with vanishing surface gravity do not exist. Our result relies on a known…

High Energy Physics - Theory · Physics 2017-11-22 Marcus Khuri , Eric Woolgar

$Q$-stars are a class of boson stars arising in scalar-field theories with interacting potentials, minimally coupled to gravity. We show that, in certain regions of parameter space, the angular velocity of stable timelike circular geodesics…

General Relativity and Quantum Cosmology · Physics 2026-03-19 Víctor Jaramillo , Laura Meneses , Héctor R. Olivares Sánchez , Carlos Herdeiro , Darío Núñez , Shuang-Yong Zhou

The gravitational instability of expanding shells triggering the formation of clouds and stars is analyzed. Disks with different scale-heights, ambient and shell velocity dispersions, mid-plane densities, rotation rates and shear rates are…

Astrophysics · Physics 2009-11-07 J. Palous , S. Ehlerova , B. G. Elmegreen

We investigate the dynamical stability of relativistic, differentially rotating, quasi-toroidal models of neutron stars through hydrodynamical simulations in full general relativity. We find that all quasi-toroidal configurations studied in…

High Energy Astrophysical Phenomena · Physics 2019-08-21 Pedro L. Espino , Vasileios Paschalidis , Thomas W. Baumgarte , Stuart L. Shapiro

We consider axially symmetric, rotating boson stars. Their flat space limits represent spinning Q-balls. We discuss their properties and determine their domain of existence. Q-balls and boson stars are stationary solutions and exist only in…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Burkhard Kleihaus , Jutta Kunz , Meike List

Stars of sufficiently low mass are convective throughout their interiors, and so do not possess an internal boundary layer akin to the solar tachocline. Because that interface figures so prominently in many theories of the solar magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-20 Matthew Browning

Neutron stars are the most compact horizonless objects in the Universe, exhibiting the strongest known magnetic fields. They are potential sources of coincident gravitational waves and electromagnetic radiation across the entire spectrum.…

High Energy Astrophysical Phenomena · Physics 2025-08-29 Fabrizio Venturi Piñas , Anson Ka Long Yip , Patrick Chi-Kit Cheong , Milton Ruiz