English

Balance with Unbounded Complexes

Commutative Algebra 2014-02-26 v1

Abstract

Given a double complex XX there are spectral sequences with the E2E_2 terms being either HI_I (HII(X))_{II}(X)) or HII(_{II}(HI(X))_I (X)). But if HI(X)=HII(X)=0H_I(X)=H_{II}(X)=0 both spectral sequences have all their terms 0. This can happen even though there is nonzero (co)homology of interest associated with XX. This is frequently the case when dealing with Tate (co)homology. So in this situation the spectral sequences may not give any information about the (co)homology of interest. In this article we give a different way of constructing homology groups of XX when HI(X)=_I(X)=HII(X)=0_{II}(X)=0. With this result we give a new and elementary proof of balance of Tate homology and cohomology.

Keywords

Cite

@article{arxiv.1108.1100,
  title  = {Balance with Unbounded Complexes},
  author = {Edgar E. Enochs and Sergio Estrada and Alina Iacob},
  journal= {arXiv preprint arXiv:1108.1100},
  year   = {2014}
}
R2 v1 2026-06-21T18:46:33.560Z