3 papers
math.CO2026
Pseudo-Geometric Strongly Regular Graphs with a Regular Point
Edwin van Dam, Krystal Guo
We study pseudo-geometric strongly regular graphs whose second subconstituent with respect to a vertex is a cover of a strongly regular graph or a complete graph. By studying the s…
math.CO2026
Seymour-tight orientations
Krystal Guo, Ross J. Kang, Gabriëlle Zwaneveld
We investigate `almost counterexamples' to Seymour's second neighbourhood conjecture. In what we call Seymour-tight orientations, the size of the first neighbourhood of each vertex…
math.CO2025
On cores of distance-regular graphs
Annemarie Geertsema, Chris Godsil, Krystal Guo
We look at the question of which distance-regular graphs are core-complete, meaning they are isomorphic to their own core or have a complete core. We build on Roberson's homomorphi…