Title: | Edge-critical subgraphs of Schrijver graphs |
Other Titles: | Hranově kritické podgrafy Schrijverových grafů |
Authors: | Kaiser, Tomáš Stehlík, Matěj |
Citation: | KAISER, T., STEHLÍK, M. Edge-critical subgraphs of Schrijver graphs. Journal of combinatorial theory series B, 2020, roč. 144, č. September 2020, s. 191-196. ISSN 0095-8956. |
Issue Date: | 2020 |
Publisher: | Academic Press |
Document type: | článek article |
URI: | 2-s2.0-85079597052 http://hdl.handle.net/11025/39641 |
ISSN: | 0095-8956 |
Keywords: | barevnost;Schrijverův graf;Kneserův graf;hranově kritický graf |
Keywords in different language: | chromatic number;Schrijver graph;Kneser graph;edge-critical graph |
Abstract in different language: | For k≥1 and n≥2k, the Kneser graph KG(n,k) has all k-element subsets of an n-element set as vertices; two such subsets are adjacent if they are disjoint. It was first proved by Lovász that the chromatic number of KG(n,k) is n−2k+2. Schrijver constructed a vertex-critical subgraph SG(n,k) of KG(n,k) with the same chromatic number. For the stronger notion of criticality defined in terms of removing edges, however, no analogous construction is known except in trivial cases. We provide such a construction for k=2 and arbitrary n≥4 by means of a nice explicit combinatorial definition. |
Rights: | Plný text není přístupný. © Academic Press |
Appears in Collections: | Články / Articles (KMA) OBD |
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