New Numerical Algorithm for Modeling of Boson-Fermion Stars in Dilatonic Gravity

Abstract

We investigate numerically a models of the static spherically symmetric boson-fermion stars in scalar-tensor theory of gravity with massive dilaton field. The proper mathematical model of such stars is interpreted as a nonlinear two-parametric eigenvalue problem with unknown internal boundary. We employ the Continuous Analogue of Newton Method (CANM) which leads on each iteration to two separate linear boundary value problems with different dimensions inside and outside the star, respectively. Along with them a nonlinear algebraic system for the spectral parameters - radius of the star $R_{s}$ and quantity $\Omega $ is solved also. In this way we obtain the behaviour of the basic geometric quantities and functions describing dilaton field and matter fields which build the star.