Scalar Field Dark Matter: non-spherical collapse and late time behavior

Abstract

We show the evolution of non-spherically symmetric balls of a self-gravitating scalar field in the Newtonian regime or equivalently an ideal self-gravitating condensed Bose gas. In order to do so, we use a finite differencing approximation of the Shcrödinger-Poisson (SP) system of equations with axial symmetry in cylindrical coordinates. Our results indicate: 1) that spherically symmetric ground state equilibrium configurations are stable against non-spherical perturbations and 2) that such configurations of the SP system are late-time attractors for non-spherically symmetric initial profiles of the scalar field, which is a generalization of such behavior for spherically symmetric initial profiles. Our system and the boundary conditions used, work as a model of scalar field dark matter collapse after the turnaround point. In such case, we have found that the scalar field overdensities tolerate non-spherical contributions to the profile of the initial fluctuation.