title: Critical Exponents Can Be Different on the Two Sides of a Transition: A Generic Mechanism.
abstract: We present models where γ(+) and γ(-), the exponents of the susceptibility in the high- and low-temperature phases, are generically different. In these models, continuous symmetries are explicitly broken down by discrete anisotropies that are irrelevant in the renormalization-group sense. The Z(q)-invariant models are the simplest examples for two-component order parameters (N=2) and the model with icosahedral symmetry for N=3. We accurately compute γ(+)-γ(-) as well as the ratio ν/ν' of the exponents of the two correlation lengths present for T<T(c).
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, UPMC-Sorbonne Universités, 75252 Paris Cedex 05, France.
authors.forename: F
authors.initials: F
authors.lastname: Léonard
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, UPMC-Sorbonne Universités, 75252 Paris Cedex 05, France.
authors.forename: B
authors.initials: B
authors.lastname: Delamotte