English

Purity of critical cohomology and Kac's conjecture

Representation Theory 2017-03-14 v7 Algebraic Geometry

Abstract

We provide a new proof of the Kac positivity conjecture for an arbitrary quiver QQ. The ingredients are the cohomological integrality theorem in Donaldson-Thomas theory, dimensional reduction, and an easy purity result. These facts imply the purity of the cohomological Donaldson-Thomas invariants for a quiver with potential (Q~,W)(\tilde{Q},W) associated to QQ, which in turn implies positivity of the Kac polynomials for QQ.

Keywords

Cite

@article{arxiv.1311.6989,
  title  = {Purity of critical cohomology and Kac's conjecture},
  author = {Ben Davison},
  journal= {arXiv preprint arXiv:1311.6989},
  year   = {2017}
}

Comments

15 pages. v6: further minor improvements, Lemma 4.4 is cleared up. v7: further minor changes thanks to referee's suggestions