English
Related papers

Related papers: An algorithm for computing the 2D structure of fas…

200 papers

We present a full 3D numerical evolution code to study neutron stars in massive-scalar-tensor theories. The code is embedded in the Einstein Toolkit framework and its implementation constitutes a modified version of the…

General Relativity and Quantum Cosmology · Physics 2026-05-19 José Carlos Olvera M. , Daniela D. Doneva , Pablo Cerdá-Durán , José A. Font , Stoytcho S. Yazadjiev

There are many factors that contribute to the breaking of the spherical symmetry of a neutron star. Most notably is rotation, magnetic fields, and/or accretion of matter from companion stars. All these phenomena influence the macroscopic…

High Energy Astrophysical Phenomena · Physics 2012-05-31 Rodrigo Negreiros , Stefan Schramm , Fridolin Weber

For an equation of state in which pressure is a function only of density, the analysis of Newtonian stellar structure is simple in principle if the system is axisymmetric, or consists of a corotating binary. It is then required only to…

Solar and Stellar Astrophysics · Physics 2010-08-12 Richard H. Price , Charalampos Markakis , John L. Friedman

This paper develops a novel numerical method for obtaining structures of rapidly rotating stars based on a self-consistent field scheme. The solution is obtained iteratively. Both rapidly rotating barotropic and baroclinic equilibrium…

Solar and Stellar Astrophysics · Physics 2015-10-21 Kotaro Fujisawa

A highly accurate, multi-domain spectral code is used in order to construct sequences of general relativistic, differentially rotating neutron stars in axisymmetry and stationarity. For bodies with a spheroidal topology and a homogeneous or…

General Relativity and Quantum Cosmology · Physics 2016-06-01 Marcus Ansorg , Dorota Gondek-Rosińska , Loïc Villain

Next-generation gravitational-wave detectors are expected to constrain the properties of extreme density matter via observations of static and dynamical tides in binary neutron star inspirals. The required modelling is straightforward in…

General Relativity and Quantum Cosmology · Physics 2025-04-10 Shanshan Yin , Nils Andersson , Fabian Gittins

Star-shaped bodies are an important nonconvex generalization of convex bodies (e.g., linear programming with violations). Here we present an efficient algorithm for sampling a given star-shaped body. The complexity of the algorithm grows…

Data Structures and Algorithms · Computer Science 2009-04-06 Karthekeyan Chandrasekaran , Daniel Dadush , Santosh Vempala

We use time-evolutions of the linear perturbation equations to study the oscillations of rapidly rotating neutrons stars. Our models account for the buoyancy due to composition gradients and we study, for the first time, the nature of the…

Astrophysics · Physics 2009-11-13 A. Passamonti , B. Haskell , N. Andersson , D. I. Jones , I. Hawke

One of the greatest challenges in interpreting the pulsations of rapidly rotating stars is mode identification, i.e. correctly matching theoretical modes to observed pulsation frequencies. Indeed, the latest observations as well as current…

Solar and Stellar Astrophysics · Physics 2017-11-08 Daniel Roy Reese , Marc-Antoine Dupret , Michel Rieutord

The 2D Euler equations are a simple but rich set of non-linear PDEs that describe the evolution of an ideal inviscid fluid, for which one dimension is negligible. Solving numerically these equations can be extremely demanding. Several…

Numerical Analysis · Mathematics 2023-01-18 Paolo Cifani , Sagy Ephrati , Milo Viviani

We present the first automated fitting method for the quantitative spectroscopy of O- and early B-type stars with stellar winds. The method combines the non-LTE stellar atmosphere code FASTWIND from Puls et al. (2005) with the genetic…

Astrophysics · Physics 2009-11-11 M. R. Mokiem , A. de Koter , J. Puls , A. Herrero , F. Najarro , M. R. Villamariz

Stellar evolution codes play a major role in present-day astrophysics, yet they share common simplifications related to the outer layers of stars. We seek to improve on this by the use of results from realistic and highly detailed 3D…

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the…

Solar and Stellar Astrophysics · Physics 2016-05-17 Joyce A. Guzik , T. H. Morgan , N. J. Nelson , C. Lovekin , K. Kosak , I. N. Kitiashvili , N. N. Mansour , A. Kosovichev

We develop a formalism to model slowly rotating superfluid Newtonian neutron stars. A two-fluid model is used to describe the matter, where one fluid is the superfluid neutrons that are believed to exist in the inner crust and core of…

Astrophysics · Physics 2009-11-06 R. Prix , G. L. Comer , N. Andersson

Neutron stars provide an ideal theoretical framework for exploring fundamental physics when nuclear matter surpasses densities encountered within atomic nuclei. Despite their paramount importance, uncertainties in the equation of state…

High Energy Astrophysical Phenomena · Physics 2025-01-31 Grigorios Papigkiotis , Georgios Vardakas , Aristidis Likas , Nikolaos Stergioulas

We present a numerical model for uniformly rotating superfluid neutron stars, for the first time with realistic microphysics including entrainment, in a fully general relativistic framework. We compute stationary and axisymmetric…

High Energy Astrophysical Phenomena · Physics 2016-11-04 Aurélien Sourie , Micaela Oertel , Jérôme Novak

We introduce numerical algorithms for initializing multidimensional simulations of stellar explosions with 1D stellar evolution models. The initial mapping from 1D profiles onto multidimensional grids can generate severe numerical…

High Energy Astrophysical Phenomena · Physics 2014-02-18 Ke-Jung Chen , Alexander Heger , Ann Almgren

We present an equation of state for elastic matter which allows for purely longitudinal elastic waves in all propagation directions, not just principal directions. The speed of these waves is equal to the speed of light whereas the…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Max Karlovini , Lars Samuelsson

Fast rotation is responsible for important changes in the structure and evolution of stars. Optical long baseline interferometry now permits the study of its effects on the stellar surface, mainly gravity darkening and flattening. We aim to…

Solar and Stellar Astrophysics · Physics 2020-01-15 K. Bouchaud , A. Domiciano de Souza , M. Rieutord , D. R. Reese , P. Kervella

We introduce the star cluster evolution code Evolve Me A Cluster of StarS (EMACSS), a simple yet physically motivated computational model that describes the evolution of some fundamental properties of star clusters in static tidal fields.…

Astrophysics of Galaxies · Physics 2015-06-04 Poul E. R. Alexander , Mark Gieles