All reports by Author Konstantinos Georgiou:

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TR10-169
| 10th November 2010
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Siavosh Benabbas, Konstantinos Georgiou, Avner Magen#### The Sherali-Adams System Applied to Vertex Cover: Why Borsuk Graphs Fool Strong LPs and some Tight Integrality Gaps for SDPs

Revisions: 2

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TR09-061
| 2nd July 2009
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Konstantinos Georgiou, Avner Magen, Madhur Tulsiani#### Optimal Sherali-Adams Gaps from Pairwise Independence

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TR06-152
| 6th December 2006
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Konstantinos Georgiou, Avner Magen, Iannis Tourlakis#### Tight integrality gaps for Vertex Cover SDPs in the Lovasz-Schrijver hierarchy

Siavosh Benabbas, Konstantinos Georgiou, Avner Magen

We study the performance of the Sherali-Adams system for VERTEX COVER on graphs with vector

chromatic number $2+\epsilon$. We are able to construct solutions for LPs derived by any number of Sherali-Adams tightenings by introducing a new tool to establish Local-Global Discrepancy. When restricted to

$O(1/ \epsilon)$ tightenings we show ...
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Konstantinos Georgiou, Avner Magen, Madhur Tulsiani

This work considers the problem of approximating fixed predicate constraint satisfaction problems (MAX k-CSP(P)). We show that if the set of assignments accepted by $P$ contains the support of a balanced pairwise independent distribution over the domain of the inputs, then such a problem on $n$ variables cannot be approximated ... more >>>

Konstantinos Georgiou, Avner Magen, Iannis Tourlakis

We prove that the integrality gap after tightening the standard LP relaxation for Vertex Cover with Omega(sqrt(log n/log log n)) rounds of the SDP LS+ system is 2-o(1).

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