I. Ojeda

activity

20152026

most citedArithmetic varieties of numerical semigroups

1 citations · 2 across the 7 of their papers we have counts for

collaborators

8 papers

math.AC2026

On the smallest numerical semigroups closed under affine maps

Amelia Álvarez, Carlos-Jesús Moreno-Ávila, Ignacio Ojeda

We study numerical semigroups $S_{a, b} (m)$ generated by the orbit of $m$ under the affine map $T_{a, b} (z) = a z + b$ , where $a \geq 2$ , $m > 1$ , $g cd (b, m) = 1$ , and $b \geq - (a - 2) m - 2$ . This ex…

math.AC2026

On Numerical Semigroups with Fixed Quotient

Ignacio Ojeda, José Carlos Rosales

Let $Δ$ be a numerical semigroup and let $d \geq 2$ be an integer. We study the fiber of the quotient map $S\mapsto S/d$ over $Δ$ . We describe its elements as semigroups of the for…

math.CA2026

On the rational solutions of generalized Abel equations

L. A. Calderon, I. Ojeda

We study the nonconstant rational solutions of generalized Abel equations \[ x'=\sum_{i=1}^s A_i(t)x^{n_i},\qquad s\geq3,\qquad 1\leq n_1<\cdots<n_s, \] with polynomial coefficient…

math.AC2026

A semigroup-theoretic linkage theory for relative ideals: principal and canonical links

Ignacio Ojeda

We develop a semigroup-theoretic analogue of liaison for relative ideals of a numerical semigroup. Two parallel linkage notions are proposed: a theory based on translates of the se…

math.GR2024

The multiples of a numerical semigroup

Ignacio Ojeda, José Carlos Rosales

Given two numerical semigroups $S$ and $T$ we say that $T$ is a multiple of $S$ if there exists an integer $d \in N ∖ {0}$ such that $S = \{x \in \mathbb{N} \mid…

math.AC2023★ 1 cited

Arithmetic varieties of numerical semigroups

Manuel B. Branco, Ignacio Ojeda, José Carlos Rosales

In this paper we present the notion of arithmetic variety for numerical semigroups. We study various aspects related to these varieties such as the smallest arithmetic that contain…

math.GR2019★ 1 cited

The set of numerical semigroups of a given multiplicity and Frobenius number

M. B. Branco, I. Ojeda, J. C. Rosales

We study the structure of the family of numerical semigroups with fixed multiplicity and Frobenius number. We give an algorithmic method to compute all the semigroups in this famil…

math.RA2015

The short resolution of a semigroup algebra

Ignacio Ojeda, Alberto Vigneron-Tenorio

This work generalizes the short resolution given in Proc. Amer. Math. Soc. \textbf{131}, 4, (2003), 1081--1091, to any affine semigroup. Moreover, a characterization of Apéry sets…