Peter J. Forrester

Eight-vertex SOS model and generalized Rogers-Ramanujan-type identities

AbstractThe eight-vertex model is equivalent to a “solid-on-solid” (SOS) model, in which an integer heightli is associated with each sitei of the square lattice. The Boltzmann weights of the model are expressed in terms of elliptic functions of period 2K, and involve a variable parameter η. Here we begin by showing that the hard hexagon model is a special case of this eight-vertex SOS model, in which η=K/5 and the heights are restricted to the range 1⩽li⩽4. We remark that the calculation of the sublattice densities of the hard hexagon model involves the Rogers-Ramanujan and related identities. We then go on to consider a more general eight-vertex SOS model, with η=K/r (r an integer) and 1⩽li⩽r−1. We evaluate the local height probabilities (which are the analogs of the sublattice densities) of this model, and are automatically led to generalizations of the Rogers-Ramanujan and similar identities. The results are put into a form suitable for examining critical behavior, and exponentsβ, α,

The Calogero-Sutherland Model and Generalized Classical Polynomials

\bar \alpha

Application of the τ -Function Theory of Painlevé Equations to Random Matrices: PIV, PII and the GUE

are obtained.

Further exact solutions of the eight-vertex SOS model and generalizations of the Rogers-Ramanujan identities

Abstract The scaled n -level distribution and scaled level spacing distribution for the small and large eigenvalues of various ensembles of random matrices are considered. Exact results for both these quantities are obtained for various special values of the parameters in the gaussian and Laguerre ensembles. On the basis of a Coulomb gas analogy, an asymptotic formula for the distribution of the smallest and largest eigenvalue is given in terms of the eigenvalue density at the spectrum edge.

Correlations for the orthogonal-unitary and symplectic-unitary transitions at the hard and soft edges

Abstract:Multivariable generalizations of the classical Hermite, Laguerre and Jacobi polynomials occur as the polynomial part of the eigenfunctions of certain Schrödinger operators for Calogero-Sutherland-type quantum systems. For the generalized Hermite and Laguerre polynomials the multidimensional analogues of many classical results regarding generating functions, differentiation and integration formulas, recurrence relations and summation theorems are obtained. We use this and related theory to evaluate the global limit of the ground state density, obtaining in the Hermite case the Wigner semi-circle law, and to give an explicit solution for an initial value problem in the Hermite and Laguerre case.

Eigenvalue statistics of the real Ginibre ensemble.

It has been remarked that a fair measure of the impact of Atle Selberg’s work is the number of mathematical terms that bear his name. One of these is the Selberg integral, an n-dimensional generalization of the Euler beta integral. We trace its sudden rise to prominence, initiated by a question to Selberg from Enrico Bombieri, more than thirty years after its initial publication. In quick succession the Selberg integral was used to prove an outstanding conjecture in random matrix theory and cases of the Macdonald conjectures. It further initiated the study of q-analogues, which in turn enriched the Macdonald conjectures. We review these developments and proceed to exhibit the sustained prominence of the Selberg integral as evidenced by its central role in random matrix theory, Calogero–Sutherland quantum many-body systems, Knizhnik–Zamolodchikov equations, and multivariable orthogonal polynomial theory.

Classical Skew Orthogonal Polynomials and Random Matrices

Abstract: Tracy and Widom have evaluated the cumulative distribution of the largest eigenvalue for the finite and scaled infinite GUE in terms of a PIV and PII transcendent respectively. We generalise these results to the evaluation of , where for and otherwise, and the average is with respect to the joint eigenvalue distribution of the GUE, as well as to the evaluation of . Of particular interest are and FN(λ;2), and their scaled limits, which give the distribution of the largest eigenvalue and the density respectively. Our results are obtained by applying the Okamoto τ-function theory of PIV and PII, for which we give a self contained presentation based on the recent work of Noumi and Yamada. We point out that the same approach can be used to study the quantities and FN(λ;a) for the other classical matrix ensembles.

EXACT STATISTICAL PROPERTIES OF THE ZEROS OF COMPLEX RANDOM POLYNOMIALS

The restricted eight-vertex solid-on-solid (SOS) model is an exactly solvable class of two-dimensional lattice models. To each sitei of the lattice there is associated an integer heightli restricted to the range 1⩽li⩽r−1. The Boltzmann weights of the model are expressed in terms of elliptic functions of period 2K, and involve a parameterη. In an earlier paper we considered the caseη=K/r. Here we generalize those considerations to the caseη=sK/r, s an integer relatively prime tor. We are again led to generalizations of the Rogers-Ramanujan identities.