English

Resolving the Module of Derivations on an $n \times (n+1)$ Determinantal Ring

Commutative Algebra 2025-05-14 v2

Abstract

We use the construction of the relative bar resolution via differential graded structures to obtain the minimal graded free resolution of DerRk\text{Der}_{R \mid k}, where RR is a determinantal ring defined by the maximal minors of an n×(n+1)n \times (n+1) generic matrix and kk is its coefficient field. Along the way, we compute an explicit action of the Hilbert-Burch differential graded algebra on a differential graded module resolving the cokernel of the Jacobian matrix whose kernel is DerRk\text{Der}_{R \mid k}. As a consequence of the minimality of the resulting relative bar resolution, we get a minimal generating set for DerRk\text{Der}_{R \mid k} as an RR-module, which, while already known, has not been obtained via our methods.

Keywords

Cite

@article{arxiv.2406.04223,
  title  = {Resolving the Module of Derivations on an $n \times (n+1)$ Determinantal Ring},
  author = {Henry Potts-Rubin},
  journal= {arXiv preprint arXiv:2406.04223},
  year   = {2025}
}