# Morita equivalences for cyclotomic Hecke algebras of type B and D

## TL;DR

This paper establishes Morita equivalences for cyclotomic quotients of affine Hecke algebras of types B and D, simplifying their representation theory by reducing it to specific cyclotomic cases.

## Contribution

It proves a Morita equivalence theorem for cyclotomic quotients of affine Hecke algebras of types B and D, extending classical results from type A.

## Key findings

- Representation theory reduces to cyclotomic quotients with eigenvalues in a single orbit.
- Decomposition theorem for generalized quiver Hecke algebras simplifies the analysis.
- Unified definitions for quiver Hecke algebras of type B are provided.

## Abstract

We give a Morita equivalence theorem for so-called cyclotomic quotients of affine Hecke algebras of type B and D, in the spirit of a classical result of Dipper-Mathas in type A for Ariki-Koike algebras. As a consequence, the representation theory of affine Hecke algebras of type B and D reduces to the study of their cyclotomic quotients with eigenvalues in a single orbit under multiplication by $q^2$ and inversion. The main step in the proof consists in a decomposition theorem for generalisations of quiver Hecke algebras that appeared recently in the study of affine Hecke algebras of type B and D. This theorem reduces the general situation of a disconnected quiver with involution to a simpler setting. To be able to treat types B and D at the same time we unify the different definitions of generalisations of quiver Hecke algebra for type B that exist in the literature.