English

Clique immersion in graphs without fixed bipartite graph

Combinatorics 2022-08-02 v2

Abstract

A graph GG contains HH as an \emph{immersion} if there is an injective mapping ϕ:V(H)V(G)\phi: V(H)\rightarrow V(G) such that for each edge uvE(H)uv\in E(H), there is a path PuvP_{uv} in GG joining vertices ϕ(u)\phi(u) and ϕ(v)\phi(v), and all the paths PuvP_{uv}, uvE(H)uv\in E(H), are pairwise edge-disjoint. An analogue of Hadwiger's conjecture for the clique immersions by Lescure and Meyniel, and independently by Abu-Khzam and Langston, states that every graph GG contains Kχ(G)K_{\chi(G)} as an immersion. We prove that for any constant ε>0\varepsilon>0 and integers s,t2s,t\ge2, there exists d0=d0(ε,s,t)d_0=d_0(\varepsilon,s,t) such that every Ks,tK_{s,t}-free graph GG with d(G)d0d(G)\ge d_0 contains a clique immersion of order (1ε)d(G)(1-\varepsilon)d(G). This implies that the above-mentioned conjecture is asymptotically true for graphs without a fixed complete bipartite graph.

Keywords

Cite

@article{arxiv.2011.10961,
  title  = {Clique immersion in graphs without fixed bipartite graph},
  author = {Hong Liu and Guanghui Wang and Donglei Yang},
  journal= {arXiv preprint arXiv:2011.10961},
  year   = {2022}
}

Comments

2 figures

R2 v1 2026-06-23T20:25:21.386Z