Maximum gradient embeddings and monotone clustering

  • Authors:
  • Manor Mendel;Assaf Naor

  • Affiliations:
  • Computer Science Division The Open University of Israel, P.O. Box 808, 1 University Rd., 43107, Raanana, Israel;Courant Institute New York University, 251 Mercer Street, 10012, New York, NY, USA

  • Venue:
  • Combinatorica
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

Let (X,d X ) be an n-point metric space. We show that there exists a distribution **image** over non-contractive embeddings into trees f: X → T such that for every x ∈ X, **image** where C is a universal constant. Conversely we show that the above quadratic dependence on log n cannot be improved in general. Such embeddings, which we call maximum gradient embeddings, yield a framework for the design of approximation algorithms for a wide range of clustering problems with monotone costs, including fault-tolerant versions of k-median and facility location.