English

Matching powers of monomial ideals and edge ideals of weighted oriented graphs

Commutative Algebra 2024-03-28 v2 Combinatorics

Abstract

We introduce the concept of matching powers of monomial ideals. Let II be a monomial ideal of S=K[x1,,xn]S=K[x_1,\dots,x_n], with KK a field. The kkth matching power of II is the monomial ideal I[k]I^{[k]} generated by the products u1uku_1\cdots u_k where u1,,uku_1,\dots,u_k is a monomial regular sequence contained in II. This concept naturally generalizes that of squarefree powers of squarefree monomial ideals. We study depth and regularity functions of matching powers of monomial ideals and edge ideals of weighted oriented graphs. We show that the last nonvanishing power of a quadratic monomial ideal is always polymatroidal and thus has a linear resolution. When II is a non-quadratic edge ideal of a weighted oriented forest, we characterize when I[k]I^{[k]} has a linear resolution.

Keywords

Cite

@article{arxiv.2309.13771,
  title  = {Matching powers of monomial ideals and edge ideals of weighted oriented graphs},
  author = {Nursel Erey and Antonino Ficarra},
  journal= {arXiv preprint arXiv:2309.13771},
  year   = {2024}
}

Comments

New version following the referees suggestions