Large induced trees in K_r-free graphs

dc.creatorFox, Jacob
dc.creatorLoh, Po-Shen
dc.creatorSudakov, Benny
dc.date2008-03-11
dc.date2008-10-25
dc.date.accessioned2026-07-07T10:12:46Z
dc.date.available2026-07-07T10:12:46Z
dc.descriptionFor a graph G, let t(G) denote the maximum number of vertices in an induced subgraph of G that is a tree. In this paper, we study the problem of bounding t(G) for graphs which do not contain a complete graph K_r on r vertices. This problem was posed twenty years ago by Erdos, Saks, and Sos. Substantially improving earlier results of various researchers, we prove that every connected triangle-free graph on n vertices contains an induced tree of order \sqrt{n}. When r >= 4, we also show that t(G) >= (\log n)/(4 \log r) for every connected K_r-free graph G of order n. Both of these bounds are tight up to small multiplicative constants, and the first one disproves a recent conjecture of Matousek and Samal.
dc.description10 pages; minor revisions
dc.identifierhttps://arxiv.org/abs/0803.1637
dc.identifierhttp://arxiv.org/abs/0803.1637
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/172294
dc.subjectCombinatorics
dc.subject05C05; 05C35; 05C55
dc.titleLarge induced trees in K_r-free graphs
dc.typetext

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