Affine Pieri rule for periodic Macdonald spherical functions and fusion rings

Abstract

Let $\hat{\mathfrak{g}}$ be an untwisted affine Lie algebra or the twisted counterpart thereof (which excludes the affine Lie algebras of type ${\widehat{BC}}_n=A_{2n}^{(2)}$). We present an affine Pieri rule for a basis of periodic Macdonald spherical functions associated with $\hat{\mathfrak{g}}$. In type ${\hat{A}}_{n-1}=A_{n-1}^{(1)}$ the formula in question reproduces an affine Pieri rule for cylindric Hall-Littlewood polynomials due to Korff, which at $t=0$ specializes in turn to a well-known Pieri formula in the fusion ring of genus zero $\widehat{\mathfrak{sl}}(n{)}_c$-Wess-Zumino-Witten conformal field theories.

25 pages

References in corpus (5)

• The Verlinde formula for Higgs bundles
• Diagonalization of an Integrable Discretization of the Repulsive Delta Bose Gas on the Circle
• Presentations of Wess-Zumino-Witten Fusion Rings
• Unitary representations of affine Hecke algebras related to Macdonald spherical functions
• A combinatorial formula for fusion coefficient