Steiner Tree Approximation via Iterative Randomized Rounding

Abstract

The Steiner tree problem is one of the most fundamental NP -hard problems: given a weighted undirected graph and a subset of terminal nodes, find a minimum-cost tree spanning the terminals. In a sequence of papers, the approximation ratio for this problem was improved from 2 to 1.55 [Robins and Zelikovsky 2005]. All these algorithms are purely combinatorial. A long-standing open problem is whether there is an LP relaxation of Steiner tree with integrality gap smaller than 2 [Rajagopalan and Vazirani 1999].

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 01, 2013
Source ID
10.1145/2432622.2432628

Entities

People

  • Fabrizio Grandoni
  • Jarosław Byrka
  • Laura Sanità
  • Thomas Rothvoss

Organizations

  • Alexander von Humboldt Foundation
  • Division of Computing and Communication Foundations
  • European Research Council
  • Foundation for Polish Science
  • Ministry of Science and Higher Education
  • Office of Naval Research
  • Swiss Federal Institute of Technology in Lausanne
  • University of Waterloo
  • University of Wrocław
  • Università della Svizzera italiana

Tags

Readers

  • Graph Algorithms and Convex Optimization.
  • Operations Research