English

Intersection homology Kunneth theorems

Geometric Topology 2011-03-31 v1 Algebraic Topology

Abstract

Cohen, Goresky and Ji showed that there is a Kunneth theorem relating the intersection homology groups IpˉH(X×Y)I^{\bar p}H_*(X\times Y) to IpˉH(X)I^{\bar p}H_*(X) and IpˉH(Y)I^{\bar p}H_*(Y), provided that the perversity pˉ\bar p satisfies rather strict conditions. We consider biperversities and prove that there is a K\"unneth theorem relating Ipˉ,qˉH(X×Y)I^{\bar p,\bar q}H_*(X\times Y) to IpˉH(X)I^{\bar p}H_*(X) and IqˉH(Y)I^{\bar q}H_*(Y) for all choices of pˉ\bar p and qˉ\bar q. Furthermore, we prove that the Kunneth theorem still holds when the biperversity p,qp,q is "loosened" a little, and using this we recover the Kunneth theorem of Cohen-Goresky-Ji.

Cite

@article{arxiv.0808.1750,
  title  = {Intersection homology Kunneth theorems},
  author = {Greg Friedman},
  journal= {arXiv preprint arXiv:0808.1750},
  year   = {2011}
}

Comments

26 pages

R2 v1 2026-06-21T11:09:50.847Z