Comparison between the fCCZ4 and BSSN formulations of Einstein equations in spherical polar coordinates

Spanish Relativity Meeting: almost 100 years after Einstein's revolution

Sanchis-Gual, N.^1 ; Montero, P.J.^2 ; Font, J.A.^1,3 ; Müller, E.^2 ; Baumgarte, T.W.^4

Departamento de Astronomía y Astrofisica, Universitat de València, Dr. Moliner 50, Burjassot (València)

46100, Spain^1

Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, Garching bei München

85748, Germany^2

Observatori Astronòmic, Universitat de València, C/ Catedrático José Beltrán 2, Paterna (València)

46980, Spain^3

Department of Physics and Astronomy, Bowdoin College, Brunswick

ME

04011, United States^4

关键词: Constraint violation;    Covariant;    Einstein equations;    Neutron stars;    Spherical coordinates;    Spherical polar coordinates;    Spherical symmetry;    Three orders of magnitude;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/600/1/012058/pdf
DOI  :  10.1088/1742-6596/600/1/012058

来源: IOP

【 摘 要 】

Recently, we generalized a covariant and conformal version of the Z4 system of the Einstein equations using a reference metric approach, that we denote as fCCZ4. We successfully implemented and tested this approach in a 1D code that uses spherical coordinates and assumes spherical symmetry, obtaining from one to three orders of magnitude reduction of the Hamiltonian constraint violations with respect to the BSSN formulation in tests involving neutron star spacetimes. In this work, we show preliminary results obtained with the 3D implementation of the fCCZ4 formulation in a fully 3D code using spherical polar coordinates.