Two-row nilpotent orbits of cyclic quivers
Abstract
Description
We prove that the local intersection cohomology of nilpotent orbit closures of cyclic quivers is trivial when the two orbits involved correspond to partitions with at most two rows. This gives a geometric proof of a result of Graham and Lehrer, which states that standard modules of the affine Hecke algebra of $GL_d$ corresponding to nilpotents with at most two Jordan blocks are multiplicity-free.
Revised version, clarified in various places. 17 pages, LaTeX and Pstricks
Revised version, clarified in various places. 17 pages, LaTeX and Pstricks