C. Dalf'o

collaborators

Showing math.COShow all

6 papers · 1 filter

math.CO2025

The Shannon capacity of graph powers

Aida Abiad, Cristina DalfÃ³, Miquel Ãngel Fiol

For a graph $G$ , its $k$ -th graph power $G^{k}$ is constructed by placing an edge between two vertices if they are within distance $k$ . We consider the problem of deriving upper boun…

math.CO2024

On the Algebraic Connectivity of Token Graphs and Graphs under Perturbations

X. Song, C. DalfÃ³, M. A. Fiol +1

Given a graph $G = (V, E)$ on $n$ vertices and an integer $k$ between 1 and $n - 1$ , the $k$ -token graph $F_{k} (G)$ has vertices representing the $k$ -subsets of $V$ , and two vertices are…

math.CO2024

On some metric properties of supertoken graphs

E. T. Baskoro, C. DalfÃ³, M. A. Fiol +1

In this paper, we construct two infinite families of graphs $G (d, c)$ and $G^{+} (d, c)$ , where, in both cases, a vertex label is $x_{1} x_{2} \dots x_{c}$ with $x_{i} \in {1, 2, \dots, d}$ . We p…

math.CO2024

Combined voltage assignments, factored lifts, and their spectra

C. DalfÃ³, M. A. Fiol, S. PavlÃkovÃ¡ +1

We consider lifting eigenvalues and eigenvectors of graphs to their {\em factored lifts}, derived by means of a {\em combined voltage assignment} in a group. The latter extends the…

math.CO2024

Some inner metric parameters of a digraph: Iterated line digraphs and integer sequences

N. H. Bong, C. DalfÃ³, M. A. Fiol +1

In this paper, we first give a new result characterizing the strongly connected digraphs with a diameter equal to that of their line digraphs. Then, we introduce the concepts of th…

math.CO2024

A note on an infinite family of graphs with all different integral Laplacian eigenvalues

C. DalfÃ³, M. A. Fiol

In this note, we give an infinite family of optimal graphs called $G^{+} (d, c)$ . They are optimal in the sense that they have the maximum possible number of vertices for given a diame…