Seminár z teórie grafov - Roman Nedela (24.11.2022)
vo štvrtok 24.11.2022 o 9:50 hod. v miestnosti M/213
Od: Martin Škoviera
Prednášajúci: Roman Nedela (Západočeská univerzita v Plzni)
Názov: Half-arc-transitive graphs of arbitrarily large girth
Termín: 24.11.2022, 9:50 hod., M 213
A graph is half-arc-transitive if it is transitive on the vertices and edges, but not on the arcs (directed edges). It is well known that a finite half-arc-transitive has an even valency greater or equal to 4. Somewhat surprisingly, all constructions of 4-valent half-arc-transitive graphs known to date have bounded girth. This led Primož Šparl ask whether there exist 4-valent half-arc-transitive graphs of arbitrarily large girth. We answer this question in the affirmative.
This is a joint work with Jozef Širáň.