title: Experimental quenching of harmonic stimuli: universality of linear response theory.
abstract: We show that liquid crystals in the weak turbulence electroconvective regime respond to harmonic perturbations with oscillations whose intensity decay with an inverse power law of time. We use the results of this experiment to prove that this effect is the manifestation of a form of linear response theory (LRT) valid in the out-of-equilibrium case, as well as at thermodynamic equilibrium where it reduces to the ordinary LRT. We argue that this theory is a universal property, which is not confined to physical processes such as turbulent or excitable media, and that it holds true in all possible conditions, and for all possible systems, including complex networks, thereby establishing a bridge between statistical physics and all the fields of research in complexity.
authors: Dipartimento di Fisica E. Fermi, Università di Pisa and INFM CRS-SOFT, Largo Pontecorvo 3, 56127 Pisa, Italy.
authors: Paolo
authors: P
authors: Allegrini
authors: Mauro
authors: M
authors: Bologna
authors: Leone
authors: L
authors: Fronzoni
authors: Paolo
authors: P
authors: Grigolini
authors: Ludovico
authors: L
authors: Silvestri