71285 event 1318592380 1475891779 <![CDATA[ARC Colloquium: Ola Svensson, École polytechnique fédérale de Lausanne EPFL]]>
We present a framework for approximating the metric TSP based on a novel use of matchings. Traditionally, matchings have been used to add edges in order to make a given graph Eulerian, whereas our approach also allows for the removal of certain edges leading to a decreased cost.

For the TSP on graphic metrics (graph-TSP), the approach yields a 1.461-approximation algorithm with respect to the Held-Karp lower bound. For graph-TSP restricted to a class of graphs that contains degree three bounded and claw-free graphs, we show that the integrality gap of the Held-Karp relaxation matches the conjectured ratio 4/3. The framework allows for generalizations in a natural way and also leads to a 1.586-approximation algorithm for the traveling salesman path problem on graphic metrics where the start and end vertices are prespecified.

This is joint work with Tobias Momke.

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We present a framework for approximating the metric TSP based on a novel use of matchings.

]]> Prasad Tetali
Director, Algorithms Research Center

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