Universality class of nonequilibrium phase transitions with infinitely many absorbing states.
We consider systems whose steady states exhibit a nonequilibrium phase transition from an active state to one-among an infinite number-absorbing state, as some control parameter is varied across a threshold value. The pair contact process, stochastic fixed-energy sandpiles, activated random walks, and many other cellular automata or reaction-diffusion processes are covered by our analysis. We argue that the upper-critical dimension below which anomalous fluctuation driven scaling appears is d(c)=6, in contrast to a widespread belief. We provide the exponents governing the critical behavior close to or at the transition point to first order in an epsilon =6-d expansion.
Van Wijland
Frédéric
F
Pôle Matière et Systèmes Complexes (CNRS FR2438, Université de Paris VII) and Laboratoire de physique théorique (CNRS UMR8627), Université de Paris-Sud, 91405 Orsay cedex, France. Frederic.van-Wijland@th.u-psud.fr