Coloring 3-colorable graphs with o(n 1/5) colors

Ken-ichi Kawarabayashi, Mikkel Thorup

10 Citations (Scopus)
2344 Downloads (Pure)

Abstract

Recognizing 3-colorable graphs is one of the most famous NP-complete problems [Garey, Johnson, and Stockmeyer STOC'74]. The problem of coloring 3-colorable graphs in polynomial time with as few colors as possible has been intensively studied: O(n1/2) colors [Wigderson STOC'82], Õ(n2/5) colors [Blum STOC'89], Õ (n3/8) colors [Blum FOCS'90], O(n1/4) colors [Karger, Motwani, Sudan FOCS'94], Õ (n3/14) = O(n0.2142) colors [Blum and Karger IPL'97], O(n0.2111) colors [Arora, Chlamtac, and Charikar STOC'06], and O(n0.2072) colors [Chlamtac FOCS'07]. Recently the authors got down to O(n0.2049) colors [FOCS'12]. In this paper we get down to O(n0.19996) = o(n1/5) colors. Since 1994, the best bounds have all been obtained balancing between combinatorial and semi-definite approaches. We present a new combinatorial recursion that only makes sense in collaboration with semi-definite programming. We specifically target the worst-case for semi-definite programming: high degrees. By focusing on the interplay, we obtained the biggest improvement in the exponent since 1997.

Original languageEnglish
Title of host publication31st International Symposium on Theoretical Aspects of Computer Science (STACS 2014)
EditorsErnst W. Mayr, Natacha Portier
Number of pages12
PublisherSchloss Dagstuhl - Leibniz-Zentrum für Informatik
Publication date1 Mar 2014
Pages458-469
ISBN (Print)978-3-939897-65-1
DOIs
Publication statusPublished - 1 Mar 2014
Event31st Symposium on Theoretical Aspects of Computer Science - ENS Lyon, Lyon, France
Duration: 5 Mar 20148 Mar 2014
Conference number: 31

Conference

Conference31st Symposium on Theoretical Aspects of Computer Science
Number31
LocationENS Lyon
Country/TerritoryFrance
CityLyon
Period05/03/201408/03/2014
SeriesLeibniz International Proceedings in Informatics
Volume25
ISSN1868-8969

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