M. Siggers

collaborators

6 papers

math.CO2025

Obstructions for homomorphisms to odd cycles in series-parallel graphs

Eun-Kyung Cho, Ilkyoo Choi, Boram Park +1

For a graph $H$ , an $H$ -colouring of a graph $G$ is a vertex map $I ¨ : V (G) \to V (H)$ such that adjacent vertices are mapped to adjacent vertices. A graph $G$ is $C_{2 k + 1}$ -critical…

math.CO2025

The complexity of matroid homomorphism reconfiguration

Cheolwon Heo, Mark Siggers

We consider a reconfiguration version of the homomorphism problem $Hom_{M} (N)$ for binary matroids $N$ . This reconfiguration problem, $Recol_{M} (N)$ , asks…

math.CO2025

Reflexive Digraph Reconfiguration by Orientation Strings

David Emmanuel PazmiÃ±o Pullas, Mark Siggers

The reconfiguration problem for homomorphisms of digraphs to a reflexive digraph cycle, which amounts to deciding if a `reconfiguration graph' is connected, is known to by polynomi…

cs.CC2025

Graph Homomorphism, Monotone Classes and Bounded Pathwidth

Tala Eagling-Vose, Barnaby Martin, Daniel Paulusma +1

In recent work by Johnson et al. (2022), a framework was described for the study of graph problems over classes specified by omitting each of a finite set of graphs as subgraphs. I…

cs.DM2024

Reconfiguring homomorphisms to reflexive graphs via a simple reduction

Moritz MÃ¼hlenthaler, Mark H. Siggers, Thomas Suzan

Given a graph $G$ and two graph homomorphisms $I^\pm$ and $I^^{2}$ from $G$ to a fixed graph $H$ , the problem $H$ -Recoloring asks whether there is a transformation from $I^\pm$ to $I^^{2}$ that…

math.GT2024

On geometric realizations of the extreme Khovanov homology of pretzel links

Jinseok Oh, Mark H. Siggers, Seung Yeop Yang +1

GonzÃ¡lez-Meneses, ManchÃ³n, and Silvero showed that the (hypothetical) extreme Khovanov homology of a link diagram is isomorphic to the reduced (co)homology of the independence si…