Xavier Mart'inez-Rivera

activity

20182021

collaborators

3 papers

math.CO2021

Combinatorial properties of the enhanced principal rank characteristic sequence over finite fields

Peter J. Dukes, Xavier Martínez-Rivera

The enhanced principal rank characteristic sequence (epr-sequence) of a symmetric matrix $B \in F^{n \times n}$ is defined as $ℓ_{1} ℓ_{2} \dots ℓ_{n}$ , where $\ell_j…

math.CO2020

On 0--1 matrices whose inverses have entries of the same modulus

Xavier Martínez-Rivera

A conjecture of Barrett, Butler and Hall may be stated as follows: If $n \geq 3$ and $A \in {0, 1}^{n \times n}$ (the family of $n \times n$ 0--1 matrices) is a nonsingular symmet…

math.CO2018

On the almost-principal minors of a symmetric matrix

Shaun M. Fallat, Xavier Martínez-Rivera

The almost-principal rank characteristic sequence (apr-sequence) of an $n \times n$ symmetric matrix is introduced, which is defined to be the string $a_{1} a_{2} \dots a_{n - 1}$ , where…