English
Related papers

Related papers: Toy Stars in two dimensions

200 papers

We study the 2-dimensional Navier-Stokes-Poisson equations with density-dependent viscosity $\theta=1/2$ without pressure of gaseous stars in astrophysics. The analytical solutions with collapsing in radial symmetry, are constructed in this…

Astrophysics · Physics 2008-11-25 Manwai Yuen

We consider a system representing self-gravitating balls of dust in an expanding Universe. It is demonstrated that one can prescribe data for such a system at infinity and evolve it backward in time without the development of shocks or…

General Relativity and Quantum Cosmology · Physics 2022-06-29 Shabnam Beheshti , Mikael Normann , Juan Valiente Kroon

In this work we study rapidly rotating stars by considering the Rastall theory of gravity. We obtain and solve the equations by numerical methods for two usual parametrization of polytropic stars. Then the mass-radius relations, moments of…

High Energy Astrophysical Phenomena · Physics 2022-01-05 F. M. da Silva , L. C. N. Santos , C. C. Barros

To simulate the dynamics of fluid with polydisperse particles on macroscale level, one has to solve hydrodynamic equations with several relaxation terms, representing momentum transfer from fluid to particles and vice versa. For small…

To simulate the expansion of the matter created in relativistic nuclear collisions, codes in 3+1 dimensions are used and we are developing a new one. To benchmark such codes, the Sod's shock tube is often used. A closely related problem is…

High Energy Physics - Phenomenology · Physics 2022-10-19 J V O Caetano , L S Nowacki , V S Franção , R Hirayama , K P Pala , J O Sola , F Grassi

The paper considers Euler-Poisson equations which govern the steady state of a self gravitating, rotating, axi-symmetric stars under the additional assumption that it is composed of incompressible stratified fluid. The original system of…

Solar and Stellar Astrophysics · Physics 2018-07-18 Mayer Humi

We study the Euler-Poisson equations of describing the evolution of the gaseous star in astrophysics. Firstly, we construct a family of analytical blowup solutions for the isothermal case in R^2. Furthermore the blowup rate of the above…

Astrophysics · Physics 2008-12-18 Manwai Yuen

Three dimensional hydrodynamic simulations of full amplitude RR Lyrae stars have been computed for several models across the instability strip. The three dimensional nature of the calculations allows convection to be treated without…

Solar and Stellar Astrophysics · Physics 2015-02-11 Christopher M. Geroux , Robert G. Deupree

In Smoothed Particles Hydrodynamics (SPH) codes with a large number of particles, star formation as well as gas and metal restitution from dying stars can be treated statistically. This approach allows to include detailed chemical evolution…

Astrophysics · Physics 2011-07-18 C. Lia , L. Portinari , G. Carraro

Non-radial oscillations of neutron stars provide a powerful probe of stellar structure and relativistic gravity, but a fully general relativistic treatment for gravitationally coupled two-fluid stars with independently conserved currents…

General Relativity and Quantum Cosmology · Physics 2026-05-06 Ankit Kumar , Daniel A. Caballero , Hajime Sotani , Nicolás Yunes

This is the second in a series of papers on the construction and validation of a three-dimensional code for the solution of the coupled system of the Einstein equations and of the general relativistic hydrodynamic equations, and on the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 J. Font , T. Goodale , S. Iyer , M. Miller , L. Rezzolla , E. Seidel , N. Stergioulas , W. Suen , M. Tobias

The equations of motion for the variance of strictly one-dimensional or two-dimensional non-relativistic fireballs are derived, from the hydrodynamic equations for an ideal, structureless Boltzmann gas. For this purpose a Gaussian number…

Mathematical Physics · Physics 2024-08-30 Fernando Haas

The paper considers Euler-Poisson equations which govern the steady state of a self gravitating, rotating, axi-symmetric fluid under the additional assumption that it is incompressible and stratified. In this setting we show that the…

Analysis of PDEs · Mathematics 2022-05-02 Mayer Humi

This article is the continued version of the analytical blowup solutions for 2-dimensional Euler-Poisson equations in "M.W. Yuen, Analytical Blowup Solutions to the 2-dimensional Isothermal Euler-Poisson Equations of Gaseous Stars, J. Math.…

Solar and Stellar Astrophysics · Physics 2009-06-02 Manwai Yuen

We construct a three-parameter family of smooth and horizonless rotating solutions of Einstein-Maxwell theory with Chern-Simons term in five dimensions and discuss their stringy origin in terms of three-charge brane systems in Type IIB and…

High Energy Physics - Theory · Physics 2025-07-24 Massimo Bianchi , Giuseppe Dibitetto , Jose F. Morales , Alejandro Ruipérez

Bouncing non-singular isotropic cosmological solutions are investigated in a simple model of scalar-tensor gravity. New families of such solutions are found and their properties are presented and analyzed using an effective potential as the…

General Relativity and Quantum Cosmology · Physics 2022-01-28 D. Polarski , A. A. Starobinsky , Y. Verbin

Smoothed Dissipative Particle Dynamics (SDPD) is a mesoscopic method which allows to select the level of resolution at which a fluid is simulated. In this work, we study the consistency of the resulting thermodynamic properties as a…

Statistical Mechanics · Physics 2016-10-19 G. Faure , J. Roussel , J. -B. Maillet , G. Stoltz

After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation.…

Astrophysics of Galaxies · Physics 2022-11-08 John Herbert Marr

We investigate the properties of interacting Q-balls and boson stars that sit on top of each other in great detail. The model that describes these solutions is essentially a (gravitating) two-scalar field model where both scalar fields are…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Yves Brihaye , Thierry Caebergs , Betti Hartmann , Momchil Minkov

We present three-dimensional self-gravitating smoothed-particle hydrodynamics (SPH) simulations of an isothermal gaseous disc interacting with an embedded planet. Discs of varying stability are simulated with planets ranging from 10…

Astrophysics · Physics 2008-11-26 Graeme Lufkin , Thomas Quinn , James Wadsley , Joachim Stadel , Fabio Governato