SPEAKER: Jonathan Comes

TITLE: Deligne's category Rep(S_t)

ABSTRACT: Recently Deligne introduced the tensor category Rep(S_t) where t is not necessarily an integer. When t is not a nonnegative integer, Rep(S_t) is a semisimple category. When t is a nonnegative integer, Rep(S_t) is a non-semisimple category which "interpolates" representations of the symmetric group S_t. In this talk I will define the category Rep(S_t) for arbitrary t, and describe the blocks of Rep(S_t) in the non-semisimple cases.