English

Asymptotic behavior of Ext for pairs of modules of large complexity over graded complete intersections

Commutative Algebra 2022-08-15 v2

Abstract

Let MM and NN be finitely generated graded modules over a graded complete intersection RR such that ExtRi(M,N)\operatorname{Ext}_R^i(M,N) has finite length for all i0i\gg 0. We show that the even and odd Hilbert polynomials, which give the lengths of ExtRi(M,N)\operatorname{Ext}^i_R(M,N) for all large even ii and all large odd ii, have the same degree and leading coefficient whenever the highest degree of these polynomials is at least the dimension of MM or NN. Refinements of this result are given when RR is regular in small codimensions.

Keywords

Cite

@article{arxiv.2012.10670,
  title  = {Asymptotic behavior of Ext for pairs of modules of large complexity over graded complete intersections},
  author = {David A. Jorgensen and Liana M. Şega and Peder Thompson},
  journal= {arXiv preprint arXiv:2012.10670},
  year   = {2022}
}

Comments

Minor edits. Final version, to appear in Mathematische Zeitschrift; 23 pages