Stationary scalar hairy configurations supported by Neumann compact stars

Abstract

We study hairy configurations constructed by stationary scalar fields outside asymptotically flat horizonless compact stars. At the star surface, we impose Neumann boundary conditions for the scalar field. With analytical methods, we obtain bounds on the frequency of stationary scalar fields.We numerically get solutions of stationary hairy stars. We also disclose effects of model parameters on the frequency of stationary scalar hairs.