DC Field | Value | Language |
---|---|---|
dc.contributor.author | Kim, Jaehoon | ko |
dc.contributor.author | Kostochka, Alexandr | ko |
dc.contributor.author | Zhu, Xuding | ko |
dc.date.accessioned | 2019-07-18T05:34:23Z | - |
dc.date.available | 2019-07-18T05:34:23Z | - |
dc.date.created | 2019-07-17 | - |
dc.date.created | 2019-07-17 | - |
dc.date.created | 2019-07-17 | - |
dc.date.issued | 2014-11 | - |
dc.identifier.citation | EUROPEAN JOURNAL OF COMBINATORICS, v.42, pp.26 - 48 | - |
dc.identifier.issn | 0195-6698 | - |
dc.identifier.uri | http://hdl.handle.net/10203/263349 | - |
dc.description.abstract | A graph G is (0, 1)-colorable if V (G) can be partitioned into two sets V-0 and V-1 so that G[V-0] is an independent set and G[V-1] has maximum degree at most I. The problem of verifying whether a graph is (0, 1)-colorable is NP-complete even in the class of planar graphs of girth 9. The maximum average degree, mad(G), of a graph G is the maximum of 2 vertical bar E(H)vertical bar/vertical bar V(H)vertical bar over all subgraphs H of G. It was proved recently that every graph G with mad(G) <= 12/5 is (0, 1)-colorable, and this is sharp. This yields that every planar graph with girth at least 12 is (0, 1)-colorable. Let F(g) denote the supremum of a such that for some constant b(g) every graph G with girth g and vertical bar E(H)vertical bar <= a vertical bar V(H)vertical bar b(g) for every H subset of G is (0, 1)-colorable. By the above, F(3) = 1.2. We find the exact value for F(4) and F(5): F(4) = F(5) = 11/9. In fact, we also find the best possible values of b(4) and b(5): every triangle-free graph G with vertical bar E(H)vertical bar < 11 vertical bar V(H)vertical bar+5/9 for every H subset of G is (0, 1)-colorable, and there are infinitely many not (0, 1)-colorable graphs G with girth 5, vertical bar E(G)vertical bar = 11 vertical bar V(G)vertical bar+5/9 and vertical bar E(H)vertical bar < 11 vertical bar V(H)vertical bar+5/9 for every proper subgraph H of G. A corollary of our result is that every planar graph of girth 11 is (0, 1)-colorable. This answers a half of a question by Dorbec, Kaiser, Montassier and Raspaud. In a companion paper, we show that for every g, F(g) <= 1.25 and resolve some similar problems for the so-called (j, k)-colorings generalizing (0, 1)-colorings. (C) 2014 Elsevier Ltd. All rights reserved. | - |
dc.language | English | - |
dc.publisher | ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD | - |
dc.title | Improper coloring of sparse graphs with a given girth, I: (0,1)-colorings of triangle-free graphs | - |
dc.type | Article | - |
dc.identifier.wosid | 000341464700003 | - |
dc.identifier.scopusid | 2-s2.0-84902489215 | - |
dc.type.rims | ART | - |
dc.citation.volume | 42 | - |
dc.citation.beginningpage | 26 | - |
dc.citation.endingpage | 48 | - |
dc.citation.publicationname | EUROPEAN JOURNAL OF COMBINATORICS | - |
dc.identifier.doi | 10.1016/j.ejc.2014.05.003 | - |
dc.contributor.localauthor | Kim, Jaehoon | - |
dc.contributor.nonIdAuthor | Kostochka, Alexandr | - |
dc.contributor.nonIdAuthor | Zhu, Xuding | - |
dc.description.isOpenAccess | N | - |
dc.type.journalArticle | Article | - |
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