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Clique immersion in graphs without fixed bipartite graph

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 نشر من قبل Donglei Yang
 تاريخ النشر 2020
  مجال البحث
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A graph $G$ contains $H$ as an emph{immersion} if there is an injective mapping $phi: V(H)rightarrow V(G)$ such that for each edge $uvin E(H)$, there is a path $P_{uv}$ in $G$ joining vertices $phi(u)$ and $phi(v)$, and all the paths $P_{uv}$, $uvin E(H)$, are pairwise edge-disjoint. An analogue of Hadwigers conjecture for the clique immersions by Lescure and Meyniel states that every graph $G$ contains $K_{chi(G)}$ as an immersion. We consider the average degree condition and prove that for any bipartite graph $H$, every $H$-free graph $G$ with average degree $d$ contains a clique immersion of order $(1-o(1))d$, implying that Lescure and Meyniels conjecture holds asymptotically for graphs without fixed bipartite graph.



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