English

Geometric representations of graded and rational Cherednik algebras

Representation Theory 2016-02-22 v2

Abstract

We provide geometric constructions of modules over the graded Cherednik algebra Hνgr\mathfrak{H}^{gr}_\nu and the rational Cherednik algebra Hνrat\mathfrak{H}^{rat}_\nu attached to a simple algebraic group G\mathbb{G} together with a pinned automorphism θ\theta. These modules are realized on the cohomology of affine Springer fibers (of finite type) that admit C\mathbb{C}^*-actions. In the rational Cherednik algebra case, the standard grading on these modules is derived from the perverse filtration on the cohomology of affine Springer fibers coming from its global analog: Hitchin fibers. When θ\theta is trivial, we show that our construction gives the irreducible finite-dimensional spherical modules Lν(triv)\mathfrak{L}_\nu(triv) of Hνgr\mathfrak{H}^{gr}_\nu and of Hνrat\mathfrak{H}^{rat}_\nu. We give a formula for the dimension of Lν(triv)\mathfrak{L}_\nu(triv) and give a geometric interpretation of its Frobenius algebra structure. The rank two cases are studied in further details.

Keywords

Cite

@article{arxiv.1407.5685,
  title  = {Geometric representations of graded and rational Cherednik algebras},
  author = {Alexei Oblomkov and Zhiwei Yun},
  journal= {arXiv preprint arXiv:1407.5685},
  year   = {2016}
}

Comments

82 pages; 8 pictures; some minor corrections; to appear in Advances in Mathematics