New code for equilibriums and quasiequilibrium initial data of compact objects

摘要: We present a new code, named COCAL---Compact Object CALculator, for the computation of equilibriums and quasiequilibrium initial data sets single or binary compact objects all kinds. In cocal those solutions are calculated on one multiple spherical coordinate patches covering hypersurface up to asymptotic region. The numerical method used solve field equations written in elliptic form is an adaptation self-consistent iterations which Green's integral formula computed using multipole expansions standard finite difference schemes. extended so that it can be computational domain with excised regions black hole companion. functions constructed various types boundary conditions imposed at surface holes. methods chosen make code simpler than any other recent codes, accepting second order accuracy perform convergence tests time symmetric patch, patches. Then, we apply obtain spatially conformally flat conditions, including based existence equilibrium apparent horizons.