English

Lengths of modules over short Artin local rings

Commutative Algebra 2023-08-01 v1

Abstract

Let (A,m)(A,\mathfrak{m}) be a short Artin local ring (i.e., m3=0\mathfrak{m}^3 = 0 and m20\mathfrak{m}^2 \neq 0). Assume AA is not a hypersurface ring. We show there exists cA2c_A \geq 2 such that if MM is any finitely generated module with bounded betti-numbers then cAc_A divides (M)\ell(M), the length of MM. If AA is not a complete intersection then there exists bA2b_A \geq 2 such that if MM is any module with curv(M)< curv(k)curv(M) < \ curv(k) then bAb_A divides (ΩAi(M))\ell(\Omega^i_A(M)) for all i1i \geq 1 (here ΩAi(M)\Omega^i_A(M) denotes the ithi^{th}-syzygy of MM).

Keywords

Cite

@article{arxiv.2307.16132,
  title  = {Lengths of modules over short Artin local rings},
  author = {Tony J. Puthenpurakal},
  journal= {arXiv preprint arXiv:2307.16132},
  year   = {2023}
}