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A new numerical method to construct binary neutron star initial data. (English) Zbl 1176.83023

Summary: We present a new numerical method for the generation of binary neutron star initial data using a method along the lines of the Wilson-Mathews or the closely related conformal thin sandwich approach. Our method uses six different computational domains, which include spatial infinity. Each domain has its own coordinates which are chosen such that the star surfaces always coincide with domain boundaries. These properties facilitate the imposition of boundary conditions. Since all our fields are smooth inside each domain, we are able to use an efficient pseudospectral method to solve the elliptic equations associated with the conformal thin sandwich approach. Currently, we have implemented corotating configurations with arbitrary mass ratios, but an extension to arbitrary spins is possible. The main purpose of this paper is to introduce our new method and to test our code for several different configurations.

MSC:

83C05 Einstein’s equations (general structure, canonical formalism, Cauchy problems)
85A05 Galactic and stellar dynamics
83-08 Computational methods for problems pertaining to relativity and gravitational theory
83C35 Gravitational waves