English

Hopfological algebra for infinite dimensional Hopf algebras

K-Theory and Homology 2019-06-05 v4 Quantum Algebra

Abstract

We consider "Hopfological" techniques as in \cite{Ko} but for infinite dimensional Hopf algebras, under the assumption of being co-Frobenius. In particular, H=k[Z]#k[x]/x2H=k[{\mathbb Z}]\#k[x]/x^2 is the first example, whose corepresentations category is d.g. vector spaces. Motivated by this example we define the "Homology functor" (we prove it is homological) for any co-Frobenius algebra, with coefficients in HH-comodules, that recover usual homology of a complex when H=k[Z]#k[x]/x2H=k[{\mathbb Z}]\#k[x]/x^2. Another easy example of co-Frobenius Hopf algebra gives the category of "mixed complexes" and we see (by computing an example) that this homology theory differs from cyclic homology, although there exists a long exact sequence analogous to the SBI-sequence. Finally, because we have a tensor triangulated category, its K0K_0 is a ring, and we prove a "last part of a localization exact sequence" for K0K_0 that allows us to compute -or describe- K0K_0 of some family of examples, giving light of what kind of rings can be categorified using this techniques.

Keywords

Cite

@article{arxiv.1904.10430,
  title  = {Hopfological algebra for infinite dimensional Hopf algebras},
  author = {Marco A. Farinati},
  journal= {arXiv preprint arXiv:1904.10430},
  year   = {2019}
}

Comments

reference added, characterization of $\mathcal H_0$ improved, typos corrected