English

Reducts of the random bipartite graph

Logic 2016-02-10 v2

Abstract

Let Γ\Gamma be the random bipartite graph, a countable graph with two infinite sides, edges randomly distributed between the sides, but no edges within a side. In this paper, we investigate the reducts of Γ\Gamma that preserve sides. We classify the closed permutation subgroups containing the group Aut(Γ)Aut(\Gamma)^*, where Aut(Γ)Aut(\Gamma)^* is the group of all isomorphisms and anti-isomorphisms of Γ\Gamma preserving the two sides. Our results rely on a combinatorial theorem of Ne\v{s}et\v{r}il-R\"{o}dl and a strong finite submodel property for Γ\Gamma.

Keywords

Cite

@article{arxiv.1101.1947,
  title  = {Reducts of the random bipartite graph},
  author = {Yun Lu},
  journal= {arXiv preprint arXiv:1101.1947},
  year   = {2016}
}