Critical behaviors of gravity under quantum perturbations
  Phase transition and critical phenomenon is a very interesting topic in thermodynamics and statistical mechanics. Gravity is believed to has deep and inherent relation to thermodynamics. Near the critical point, the perturbation becomes significant. Thus for ordinary matter (govern by interactions besides gravity) the critical behavior will become very different if we ignore the perturbations around the critical point, such as mean field theory. We find that the critical exponents for RN-AdS spacetime keeps the same values even we consider the full quantum perturbations. This indicates a key difference between gravity and ordinary thermodynamic system. 
Hongsheng Zhang, Xin-Zhou Li
gr-qc cond-mat.stat-mech hep-th