3 papers
math.CO2019
H-Kernels by Walks
Hortensia Galeana-Sanchez, Hugo Rincon-Galeana, Ricardo Strausz
We prove that, if every cycle of is an -cycle, then has an -kernel by walks.
math.CO2015
On Panchromatic Patterns
Hortensia Galeana-Sanchez, Ricardo Strausz
Given D and H two digraphs, D is H-coloured iff the arcs of D are coloured with the vertices of H. After defining what do we mean by an H-walk in the coloured D, we characterise th…
math.CO2011
A graph-theoretical axiomatization of oriented matroids
Kolja Knauer, Juan Jose Montellano-Ballesteros, Ricardo Strausz
We characterize which systems of sign vectors are the cocircuits of an oriented matroid in terms of the cocircuit graph.