English

Cotorsion pairs in Hopfological algebra

K-Theory and Homology 2020-12-15 v1

Abstract

In an intriguing paper arXiv:math/0509083 Khovanov proposed a generalization of homological algebra, called Hopfological algebra. Since then, several attempts have been made to import tools and techiniques from homological algebra to Hopfological algebra. For example, Qi arXiv:1205.1814 introduced the notion of cofibrant objects in the category CA,HH\mathbf{C}_{A,H}^{H} of HH-equivariant modules over an HH-module algebra AA, which is a counterpart to the category of modules over a dg algebra, although he did not define a model structure on CA,HH\mathbf{C}_{A,H}^{H}. In this paper, we show that there exists an Abelian model structure on CA,HH\mathbf{C}_{A,H}^{H} in which cofibrant objects agree with Qi's cofibrant objects under a slight modification. This is done by constructing cotorsion pairs in CA,HH\mathbf{C}_{A,H}^{H} which form a Hovey triple in the sense of Gillespie arXiv:1512.06001. This can be regarded as a Hopfological analogues of the works of Enochs, Jenda, and Xu and of Avramov, Foxby, and Halperin. By restricting to compact cofibrant objects, we obtain a Waldhausen category PerfA,HH\mathcal{P}\mathrm{erf}_{A,H}^{H} of perfect objects. By taking invariants of this Waldhausen category, such as algebraic KK-theory, Hochschild homology, cyclic homology, and so on, we obtain Hopfological analogues of these invariants.

Keywords

Cite

@article{arxiv.2012.07159,
  title  = {Cotorsion pairs in Hopfological algebra},
  author = {Mariko Ohara and Dai Tamaki},
  journal= {arXiv preprint arXiv:2012.07159},
  year   = {2020}
}

Comments

31 pages

R2 v1 2026-06-23T20:56:11.378Z