Hecke algebras for inner forms of p-adic special linear groups

Abstract

Let F be a non-archimedean local field and let $G^\sharp$ be the group of F-rational points of an inner form of $SL_n$. We study Hecke algebras for all Bernstein components of $G^\sharp$, via restriction from an inner form G of $GL_n (F)$. For any packet of L-indistinguishable Bernstein components, we exhibit an explicit algebra whose module category is equivalent to the associated category of complex smooth $G^\sharp$-representations. This algebra comes from an idempotent in the full Hecke algebra of $G^\sharp$, and the idempotent is derived from a type for G. We show that the Hecke algebras for Bernstein components of $G^\sharp$ are similar to affine Hecke algebras of type A, yet in many cases are not Morita equivalent to any crossed product of an affine Hecke algebra with a finite group.