Experimental approaches to universal out-of-equilibrium scaling laws: turbulent liquid crystal and other developments

This is a brief survey of recent experimental studies on out-ofequilibrium scaling laws, focusing on two prominent situations where nontrivial universality classes have been identified theoretically: absorbing-state phase transitions and growing interfaces.First the paper summarizes the main results obtained for electrically driven turbulent liquid crystals, which exhibited the scaling laws for the directed percolation class at the transition between two turbulent regimes, and those for the Kardar-Parisi-Zhang class in the supercritical phase where one turbulent regime invades the other.Other experimental investigations on these universality classes and related situations are then overviewed and discussed.Some remarks on analyses of these scaling laws are also given from the practical viewpoint.