Roberto C. D'iaz

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math.CO2021

Perturbing eigenvalues of nonnegative centrosymmetric matrices

Roberto C. Díaz, Ana I. Julio, Yankis R. Linares

An $n \times n$ matrix $C$ is said to be {\it centrosymmetric} if it satisfies the relation $J C J = C$ , where $J$ is the $n \times n$ counteridentity matrix. Centrosymmetric matrices ha…

math.CO2021

On the Randić energy of caterpillar graphs

Domingos M. Cardoso, Paula Carvalho, Roberto C. Díaz +1

A caterpillar graph $T (p_{1}, \dots, p_{r})$ of order $n = r + \sum_{i = 1}^{r} p_{i}$ , $r \geq 2$ , is a tree such that removing all its pendent vertices gives rise to a path of order $r$ . In t…