Ignacio Ojeda

collaborators

3 papers

math.AC2023

Universally free numerical semigroups

Ignacio García Marco, Pedro A. García-Sánchez, Ignacio Ojeda +1

A numerical semigroup is said to be universally free if it is free for any possible arrangement of its minimal generating set. In this work, we establish that toric ideals associat…

math.CA2023

Rational Limit Cycles of Abel Differential Equations

José Luis Bravo Trinidad, Luis Ángel Calderón Pérez, Ignacio Ojeda Martínez de Castilla

We study the number of rational limit cycles of the Abel equation $x^{'} = A (t) x^{3} + B (t) x^{2}$ , where $A (t)$ and $B (t)$ are real trigonometric polynomials. We show that this number is at m…

math.AC2021

The Frobenius problem for generalized repunit numerical semigroups

Manuel B. Branco, Isabel Colaço, Ignacio Ojeda

In this paper, we introduce and study the numerical semigroups generated by ${a_{1}, a_{2}, \dots} \subset N$ such that $a_{1}$ is the repunit number in base $b > 1$ of leng…