Homomorphisms of signed bipartite graphs

Reza Naserasr (1, 2) , Edita Rollova (3) , Eric Sopena (1)

1 LaBRI - Laboratoire Bordelais de Recherche en Informatique
2 LRI - Laboratoire de Recherche en Informatique
3 Department of Mathematics

We study the homomorphism relation between signed graphs where the underlying graph G is bipartite. We show that this notion captures the notions of chromatic number and graph homomorphisms. In particular we will study Hadwiger's conjecture in this setting. We show that for small values of the chromatic number there are natural strengthening of this conjecture but such extensions will not work for larger chromatic numbers.

Domaines: Mathématique discrète [cs.DM]

Reza Naserasr, Edita Rollova, Eric Sopena. Homomorphisms of signed bipartite graphs. European Conference on Combinatorics, Graph Theory and Applications - Eurocomb 2013, Sep 2013, Pisa, Italy. pp.1-5. ⟨hal-00829116⟩