I. Ojeda

collaborators

4 papers

math.AC2026

On the smallest numerical semigroups closed under affine maps

Amelia Ãlvarez, Carlos-JesÃºs Moreno-Ãvila, 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

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.AC2026

On Numerical Semigroups with Fixed Quotient

Let $I^$ 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 $I^$ . We describe its elements as semigroups of the f…

math.CA2026

On the rational solutions of generalized Abel equations

L. A. Calderon, I. Ojeda

We study nonconstant rational solutions of \[ x'=A_3(t)x^{n_3}+A_2(t)x^{n_2}+A_1(t)x^{n_1}, \qquad 1<n_1<n_2<n_3, \] with $A_{i} \in k [t]$ , $k \in {R, C}$ . We pr…