English

Nearly Gorenstein and almost symmetric properties in shifted numerical semigroups

Commutative Algebra 2026-01-28 v1

Abstract

Given the integers 0<r1<<rk0<r_1<\dots<r_k, we consider the shifted family of semigroups Mn=n,n+r1,,n+rkM_n=\langle n, n+r_1,\dots, n+r_k\rangle, where n>0n>0. For sufficiently large nn, we prove that if MnM_n is nearly Gorenstein or almost symmetric, then so is Mn+rkM_{n+r_k}. A key ingredient is to relate the pseudo-Frobenius elements of MnM_n and Mn+rkM_{n+r_k}, correcting a wrong claim in the literature. Moreover, we derive explicit formulas for the Frobenius and pseudo-Frobenius numbers of Mn+rkM_{n+r_k}.

Keywords

Cite

@article{arxiv.2601.19629,
  title  = {Nearly Gorenstein and almost symmetric properties in shifted numerical semigroups},
  author = {Dumitru I. Stamate and Francesco Strazzanti},
  journal= {arXiv preprint arXiv:2601.19629},
  year   = {2026}
}