Phase transitions of magnetic AdS4 black holes with scalar hair

Abstract

We determine the thermodynamic properties of a class of spherically symmetric and static black holes in AdS4 with magnetic charges and scalar hair. These black holes are solutions in four-dimensional N=2 gauged supergravity that can arise from 11-dimensional supergravity compactified on S7. At zero temperature, they preserve supersymmetry and hence are stable. At nonzero temperatures, we explore in detail the canonical ensemble and stability of solutions and find a first-order phase transition between small and large hairy black holes. The transition emerges as a liquid-gas phase transition in the dual three-dimensional field theory on R×S2 with magnetic flux through S2.