The mirabolic Hecke algebra
arXiv:1310.3878 · doi:10.1016/j.jalgebra.2014.02.008
Abstract
The Iwahori-Hecke algebra of the symmetric group is the convolution algebra of $\gl_n$-invariant functions on the variety of pairs of complete flags over a finite field. Considering convolution on the space of triples of two flags and a vector we obtain the mirabolic Hecke algebra , which had originally been described by Solomon. In this paper we give a new presentation for which shows that it is a quotient of a cyclotomic Hecke algebra, as defined by Ariki and Koike. From this we recover the results of Siegel about the representations of . We use Jucys-Murphy elements to describe the center of and to give a -structure on the Grothendieck group of the category of its representations, giving `mirabolic' analogues of classical results about the Iwahori-Hecke algebra. We also outline a strategy towards a proof of the conjecture that the mirabolic Hecke algebra is a cellular algebra.
27 pages