New numerical method for constructing quasiequilibrium sequences of irrotational binary neutron stars in general relativity

摘要: We propose a new numerical method to compute quasi-equilibrium sequences of general relativistic irrotational binary neutron star systems. It is good approximation assume that (1) the system irrotational, i.e. vorticity flow field inside component stars vanishes everywhere (irrotational flow), and (2) in quasi-equilibrium, for an inspiraling just before coalescence as result gravitational wave emission. can introduce velocity potential such field, which satisfies elliptic partial differential equation (PDE) with Neumann type boundary condition at stellar surface. For treatment gravity, we use Wilson--Mathews formulation, assumes conformal flatness spatial components metric. In this basic equations are expressed by PDEs. have developed solve these PDEs appropriate conditions. The based on established prescription computing equilibrium states rapidly rotating axisymmetric or Newtonian checked reliability our code comparing results those other computations available. also performed several convergence tests. By using code, obtained systems strong gravity models final real evolution coalescence. Analysis shows may not suffer from dynamical instability orbital motion maximum density does increase separation decreases.