title: Universal free-energy distribution in the critical point of a random Ising ferromagnet.
abstract: We discuss the non-self-averaging phenomena in the critical point of weakly disordered Ising ferromagnet. In terms of the renormalized replica Ginzburg-Landau Hamiltonian in dimensions D<4, we derive an explicit expression for the probability distribution function (PDF) of the critical free-energy fluctuations. In particular, using known fixed-point values for the renormalized coupling parameters, we obtain the universal curve for such PDF in the dimension D=3. It is demonstrated that this function is strongly asymmetric: its left tail is much slower than the right one.
authors.affiliation: LPTMC, Université Paris VI, 75252 Paris, France and L. D. Landau Institute for Theoretical Physics, 119334 Moscow, Russia.
authors.forename: Victor
authors.initials: V
authors.lastname: Dotsenko
authors.affiliation: Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 79011 Lviv, Ukraine.
authors.forename: Yurij
authors.initials: Y
authors.lastname: Holovatch