3 papers
math.CO2026
Logical aspects of isomorphism of controllable graphs and cospectrality of distance-regularized graphs
Aida Abiad, Anuj Dawar, Octavio B. Zapata-Fonseca
We consider isomorphism of controllable graphs and cospectrality of distance-regularized graphs (which are known to be distance-regular or distance-biregular) in relation to logica…
math.CO2025
Quasi-strongly regular graphs on the flags of symmetric designs
Eugenia O'Reilly-Regueiro, Octavio B. Zapata-Fonseca
This paper was inspired by a paper by Blokhuis and Brouwer [Designs, Codes and Cryptography 65, 2012] in which a definition of a graph on the flags of a biplane is given, and they…
math.CO2025
Edge-transitive token graphs as covers
Sergio G. Gómez-Galicia, Octavio B. Zapata-Fonseca
This paper uses the theory of covering graphs to characterize some of the edge-transitive graphs which can arise as token graphs.