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 language | English |
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Title of host publication | 31st International Symposium on Theoretical Aspects of Computer Science (STACS 2014) |
Editors | Ernst W. Mayr, Natacha Portier |
Number of pages | 12 |
Publisher | Schloss Dagstuhl - Leibniz-Zentrum für Informatik |
Publication date | 1 Mar 2014 |
Pages | 458-469 |
ISBN (Print) | 978-3-939897-65-1 |
DOIs | |
Publication status | Published - 1 Mar 2014 |
Event | 31st Symposium on Theoretical Aspects of Computer Science - ENS Lyon, Lyon, France Duration: 5 Mar 2014 → 8 Mar 2014 Conference number: 31 |
Conference
Conference | 31st Symposium on Theoretical Aspects of Computer Science |
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Number | 31 |
Location | ENS Lyon |
Country/Territory | France |
City | Lyon |
Period | 05/03/2014 → 08/03/2014 |
Series | Leibniz International Proceedings in Informatics |
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Volume | 25 |
ISSN | 1868-8969 |