We consider a reconfiguration version of the homomorphism problem HomM(N) for binary matroids N. This reconfiguration problem, RecolM(N), asks, for two homomorphisms ϕ and ψ of a matroid M to N, if there is a path of homomorphism from ϕ to ψ such that consecutive homomorphism in the path differ on a single cocircuit of N. We show that this problem is trivial in the case that N dismantles to the graphic matroid M(K2), and that the problem is PSPACE-complete when N is the graphic matroid M(K3), M(K4), or any graphic matroid containing M(K5).
@article{arxiv.2503.19181,
title = {The complexity of matroid homomorphism reconfiguration},
author = {Cheolwon Heo and Mark Siggers},
journal= {arXiv preprint arXiv:2503.19181},
year = {2025}
}