Gaussian and their Subordinated Self-similar Random Generalized Fields

A large class of generalized random fields is defined, containing random elements F of J', where J' is the dual of the Schwartz space J = J(R^ν). Such a generalized random field is translation-invariant if Fφ is the same as Fψ for any translate ψ of φ; it is invariant under the renormalization group with index _κ (or self-similar with index _κ) if Fφ_λ = λ-αFφ for all λ > 0 and φ ∈ L, where φ_λ is the rescaled test function φ_λ(x) = λ-νφ(x/λ). Recent work of several authors has shown that self-similar generalized random fields on R^ν, and self-similar random fields on Z^ν which can be constructed from them, arise naturally in problems of statistical mechanics and limit laws of probability theory. They generalize the theory of stable distributions. Here the class of all translation-invariant self-similar Gaussian generalized random fields on R^ν is completely described. By the discretization of such fields the class of self-similar Gaussian fields with discrete arguments (found by Sinai) is extended. Finally, a class of generalized random fields subordinated to the self-similar translation-invariant Gaussian ones is constructed. These non-Gaussian generalized random fields are Wick powers (multiple Ito integrals) of the Gaussian ones.