Abstract
We use category-theoretic techniques to provide two proofs show-ing that for a higher-rank graph Λ, its cubical (co-)homology and categorical (co-)homology groups are isomorphic in all degrees, thus answering a question of Kumjian, Pask and Sims in the positive. Our first proof uses the topological realization of a higher-rank graph, which was introduced by Kaliszewski, Kumjian, Quigg, and Sims. In our more combinatorial second proof, we con-struct, explicitly and in both directions, maps on the level of (co-)chain com-plexes that implement said isomorphism. Along the way, we extend the defi-nition of cubical (co-)homology to allow arbitrary coefficient modules.
| Original language | English |
|---|---|
| Pages (from-to) | 442-480 |
| Number of pages | 39 |
| Journal | Transactions of the American Mathematical Society Series B |
| Volume | 8 |
| Issue number | 16 |
| DOIs | |
| State | Published - Jun 10 2021 |
Funding
Received by the editors July 19, 2018, and, in revised form, January 26, 2019. 2020 Mathematics Subject Classification. Primary 18G90; Secondary 55N10. The first author was partially supported by the Deutsches Forschungsgemeinschaft via the SFB 878 “Groups, Geometry, and Actions.” The second author was partially supported by NSF grant #DMS–1564401.
| Funder number |
|---|
| –1564401 |
| SFB 878 |