Rational Cherednik algebras and applications

by Maurizio Martino, Université de Bonn.

Rational Cherednik algebras were introduced by Etingof and Ginzburg as a family of deformations of certain invariant rings related to complex reflection groups. These interesting algebras have subsequently been shown to have very interesting properties and have many applications to representation theory, algebraic combinatroics and geometry.
We will focus on the representation theory of rational Cherednik algebras and in particular their "highest weight category" of modules, also known as category O. It turns out that a crucial ingredient in the theory is the KZ functor from this category to the category of modules for a certain cyclotomic Hecke algebra (at a root of unity). For wreath products of a symmetric group and a cyclic group category O behaves in many ways like the category of modules for cyclotomic q-Schur algebra: for instance, the KZ functor is much like the Schur functor. In fact it is a theorem of Rouquier that for certain parameters of the rational Cherednik algebras these two categories are equivalent. In general however, category O provides a new analogue of the q-Schur algebra.
We shall explain in our lectures the above theory and, time permitting, shall discuss the "t=0" theory which mirrors (at least conjecturally) generic behaviour of Hecke algebras.