The Lagrangian numerical relativity code SPHINCS_BSSN_v1.0

Frontiers in Applied Mathematics and Statistics

Applied Mathematics and Statistics

Peter Diener¹  Francesco Torsello²  Stephan Rosswog³ 

[1] Center for Computation & Technology, Louisiana State University, Baton Rouge, LA, United States;Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA, United States;Department of Astronomy, The Oskar Klein Centre, AlbaNova, Stockholm University, Stockholm, Sweden;Department of Physics, University of Hamburg, Hamburger Sternwarte, Hamburg, Germany;Department of Astronomy, The Oskar Klein Centre, AlbaNova, Stockholm University, Stockholm, Sweden;

关键词: numerical relativity;    gravitational waves;    neutron stars;    smooth particle hydrodynamics;    initial data;   

DOI  :  10.3389/fams.2023.1236586

 received in 2023-06-08, accepted in 2023-08-30,  发布年份 2023

来源: Frontiers

【 摘 要 】

We present version 1.0 of our Lagrangian numerical relativity code SPHINCS_BSSN. This code evolves the full set of Einstein equations, but contrary to other numerical relativity codes, it evolves the matter fluid via Lagrangian particles in the framework of a high-accuracy version of smooth particle hydrodynamics (SPH). The major new elements introduced here are: (i) a new method to map the stress–energy tensor (known at the particles) to the spacetime mesh, based on a local regression estimate; (ii) additional measures that ensure the robust evolution of a neutron star through its collapse to a black hole; and (iii) further refinements in how we place the SPH particles for our initial data. The latter are implemented in our code SPHINCS_ID which now, in addition to LORENE, can also couple to initial data produced by the initial data library FUKA. We discuss several simulations of neutron star mergers performed with SPHINCS_BSSN_v1.0, including irrotational cases with and without prompt collapse and a system where only one of the stars has a large spin (χ = 0.5).

【 授权许可】

Unknown   
Copyright © 2023 Rosswog, Torsello and Diener.