No scalar hair theorem for neutral Neumann stars: static massive scalar fields nonminimally coupled to gravity

In a recent paper, Hod proved that spherically symmetric Dirichlet reflecting compact stars cannot support static nonminimally coupled scalar fields. In the present paper, we study the validity of no hair theorems for compact stars with Neumann surface boundary conditions. We find that Neumann compact stars cannot support static massive scalar field hairs with a generic dimensionless nonminimal coupling parameter.