Inverse Symmetry Breaking and the Exact Renormalization Group
  We discuss the question of inverse symmetry breaking at non-zero temperature using the exact renormalization group. We study a two-scalar theory and concentrate on the nature of the phase transition during which the symmetry is broken. We also examine the persistence of symmetry breaking at temperatures higher than the critical one. 
M. Pietroni, N. Rius and N. Tetradis (CERN)