English

Kac's conjecture from Nakajima quiver varieties

Representation Theory 2010-03-17 v2 Algebraic Geometry

Abstract

We prove a generating function formula for the Betti numbers of Nakajima quiver varieties. We prove that it is a q-deformation of the Weyl-Kac character formula. In particular this implies that the constant term of the polynomial counting the number of absolutely indecomposable representations of a quiver equals the multiplicity of a a certain weight in the corresponding Kac-Moody algebra, which was conjectured by Kac in 1982.

Keywords

Cite

@article{arxiv.0811.1569,
  title  = {Kac's conjecture from Nakajima quiver varieties},
  author = {Tamas Hausel},
  journal= {arXiv preprint arXiv:0811.1569},
  year   = {2010}
}

Comments

12 pages; minor changes, to appear in Inventiones Mathematicae

R2 v1 2026-06-21T11:40:07.402Z