Abstract
We consider the maximum independent set problem on graphs with maximum degree d. We show that the integrality gap of the Lovasz Theta function-based SDP has an integrality gap of O~(d/log3/2 d). This improves on the previous best result of O~(d/log d), and narrows the gap of this basic SDP to the integrality gap of O~(d/log2 d) recently shown for stronger SDPs, namely those obtained using poly log(d) levels of the SA+ semidefinite hierarchy. The improvement comes from an improved Ramsey-theoretic bound on the independence number of Kr-free graphs for large values of r.
We also show how to obtain an algorithmic version of the above-mentioned SAplus-based integrality gap result, via a coloring algorithm of Johansson. The resulting approximation guarantee of O~(d/log2 d) matches the best unique-games-based hardness result up to lower-order poly (log log d) factors.
Original language | English |
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Title of host publication | 47th Annual ACM Symposium on the Theory of Computing (STOC'15, Portland OR, USA, June 14-17, 2015) |
Editors | R.A. Servedio, R. Rubinfeld |
Place of Publication | New York NY |
Publisher | Association for Computing Machinery, Inc |
Pages | 193-200 |
ISBN (Print) | 978-1-4503-3536-2 |
DOIs | |
Publication status | Published - 2015 |
Event | 47th ACM Symposium on the Theory of Computing (STOC 2015), June 14-17, 2015, Portland, OR, USA - Portland, OR, United States Duration: 14 Jun 2015 → 17 Jun 2015 http://acm-stoc.org/stoc2015/ |
Conference
Conference | 47th ACM Symposium on the Theory of Computing (STOC 2015), June 14-17, 2015, Portland, OR, USA |
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Abbreviated title | STOC 2015 |
Country/Territory | United States |
City | Portland, OR |
Period | 14/06/15 → 17/06/15 |
Internet address |