Schwarzschild black holes can wear scalar wigs

Phys Rev Lett. 2012 Aug 24;109(8):081102. doi: 10.1103/PhysRevLett.109.081102. Epub 2012 Aug 22.

Abstract

We study the evolution of a massive scalar field surrounding a Schwarzschild black hole and find configurations that can survive for arbitrarily long times, provided the black hole or the scalar field mass is small enough. In particular, both ultralight scalar field dark matter around supermassive black holes and axionlike scalar fields around primordial black holes can survive for cosmological times. Moreover, these results are quite generic in the sense that fairly arbitrary initial data evolve, at late times, as a combination of those long-lived configurations.