English

Derived functors and Hilbert polynomials over regular local rings

Commutative Algebra 2024-12-04 v1

Abstract

Let (A,m)(A,\mathfrak{m}) be a regular local ring of dimension d1d \geq 1, II an m\mathfrak{m}-primary ideal. Let NN be a non-zero finitely generated AA-module. Consider the functions tI(N,n)=i=0d(ToriA(N,A/In)) and eI(N,n)=i=0d(ExtAi(N,A/In)) t^I(N, n) = \sum_{i = 0}^{ d}\ell(\text{Tor}^A_i(N, A/I^n)) \ \text{and}\ e^I(N, n) = \sum_{i = 0}^{ d}\ell(\text{Ext}_A^i(N, A/I^n)) of polynomial type and let their degrees be tI(N)t^I(N) and eI(N)e^I(N). We prove that tI(N)=eI(N)=max{dimN,d1}t^I(N) = e^I(N) = \max\{ \dim N, d -1 \}.

Keywords

Cite

@article{arxiv.2312.16982,
  title  = {Derived functors and Hilbert polynomials over regular local rings},
  author = {Tony J. Puthenpurakal},
  journal= {arXiv preprint arXiv:2312.16982},
  year   = {2024}
}
R2 v1 2026-06-28T14:03:39.454Z