Surface operator content of the A_L face models

A set of fixed boundary weights for both the critical dense and dilute A_L face models is constructed from the known boundary weights of the related loop model. The surface operator content and the conformal partition functions then follow from the results obtained via the Bethe equations.Comment: 12 pages, LaTeX, 2 eps figs, Elsevier style files, to appear in the Hans van Leeuwen festschrift (Physica A

The Andrews-Gordon identities and qq-multinomial coefficients

We prove polynomial boson-fermion identities for the generating function of the number of partitions of $n$ of the form $n=\sum_{j=1}^{L-1} j f_j$, with $f_1\leq i-1$, $f_{L-1} \leq i'-1$ and $f_j+f_{j+1}\leq k$. The bosonic side of the identities involves $q$-deformations of the coefficients of $x^a$ in the expansion of $(1+x+\cdots+ x^k)^L$. A combinatorial interpretation for these $q$-multinomial coefficients is given using Durfee dissection partitions. The fermionic side of the polynomial identities arises as the partition function of a one-dimensional lattice-gas of fermionic particles. In the limit $L\to\infty$, our identities reproduce the analytic form of Gordon's generalization of the Rogers--Ramanujan identities, as found by Andrews. Using the $q \to 1/q$ duality, identities are obtained for branching functions corresponding to cosets of type $({\rm A}^{(1)}_1)_k \times ({\rm A}^{(1)}_1)_{\ell} / ({\rm A}^{(1)}_1)_{k+\ell}$ of fractional level $\ell$.Comment: 31 pages, Latex, 9 Postscript figure

Extensions of the well-poised and elliptic well-poised Bailey lemma

We establish a number of extensions of the well-poised Bailey lemma and elliptic well-poised Bailey lemma. As application we prove some new transformation formulae for basic and elliptic hypergeometric series, and embed some recent identities of Andrews, Berkovich and Spiridonov in a well-poised Bailey tree.Comment: 16 pages, AMS-LaTeX, to appear in Indag. Math. (N.S.

The generalized Borwein conjecture. II. Refined q-trinomial coefficients

Transformation formulas for four-parameter refinements of the q-trinomial coefficients are proven. The iterative nature of these transformations allows for the easy derivation of several infinite series of q-trinomial identities, and can be applied to prove many instances of Bressoud's generalized Borwein conjecture.Comment: 36 pages, AMS-LaTe

Solvable RSOS models based on the dilute BWM algebra

In this paper we present representations of the recently introduced dilute Birman-Wenzl-Murakami algebra. These representations, labelled by the level-$l$ B$^{(1)}_n$, C$^{(1)}_n$ and D$^{(1)}_n$ affine Lie algebras, are Baxterized to yield solutions to the Yang-Baxter equation. The thus obtained critical solvable models are RSOS counterparts of the, respectively, D$^{(2)}_{n+1}$, $A^{(2)}_{2n}$ and B$^{(1)}_n$ $R$-matrices of Bazhanov and Jimbo. For the D$^{(2)}_{n+1}$ and B$^{(1)}_n$ algebras the RSOS models are new. An elliptic extension which solves the Yang-Baxter equation is given for all three series of dilute RSOS models.Comment: 25 pages, uuencoded compressed PostScript file, Amsterdam preprint ITFA-94-2

Critical behaviour of the dilute O(n), Izergin-Korepin and dilute ALA_L face models: Bulk properties

The analytic, nonlinear integral equation approach is used to calculate the finite-size corrections to the transfer matrix eigen-spectra of the critical dilute O(n) model on the square periodic lattice. The resulting bulk conformal weights extend previous exact results obtained in the honeycomb limit and include the negative spectral parameter regimes. The results give the operator content of the 19-vertex Izergin-Korepin model along with the conformal weights of the dilute $A_L$ face models in all four regimes.Comment: 23 pages, no ps figures, latex file, to appear in NP