3 papers
math.CO2024
Planar Graphs with Homomorphisms to the 9-cycle
Daniel W. Cranston, Jiaao Li, Zhouningxin Wang +1
We study the problem of finding homomorphisms into odd cycles from planar graphs with high odd-girth. The Jaeger-Zhang conjecture states that every planar graph of odd-girth at lea…
math.CO2023
Density of -critical signed graphs
Laurent Beaudou, Penny Haxell, Kathryn Nurse +2
We say that a signed graph is -critical if it is not -colorable but every one of its proper subgraphs is -colorable. Using the definition of colorability due to Naserasr,…
math.CO2023
Critically 3-frustrated signed graphs
Chiara Cappello, Reza Naserasr, Eckhard Steffen +1
Extending the notion of maxcut, the study of the frustration index of signed graphs is one of the basic questions in the theory of signed graphs. Recently two of the authors initia…