Title
Embedding k-Outerplanar Graphs into l1
Abstract
We show that the shortest-path metric of any $k$-outerplanar graph, for any fixed $k$, can be approximated by a probability distribution over tree metrics with constant distortion and hence also embedded into $\ell_1$ with constant distortion. These graphs play a central role in polynomial time approximation schemes for many NP-hard optimization problems on general planar graphs and include the family of weighted $k\times n$ planar grids. This result implies a constant upper bound on the ratio between the sparsest cut and the maximum concurrent flow in multicommodity networks for $k$-outerplanar graphs, thus extending a theorem of Okamura and Seymour [J. Combin. Theory Ser. B, 31 (1981), pp. 75-81] for outerplanar graphs, and a result of Gupta et al. [Combinatorica, 24 (2004), pp. 233-269] for treewidth-2 graphs. In addition, we obtain improved approximation ratios for $k$-outerplanar graphs on various problems for which approximation algorithms are based on probabilistic tree embeddings. We conjecture that these embeddings for $k$-outerplanar graphs may serve as building blocks for $\ell_1$ embeddings of more general metrics.
Year
DOI
Venue
2003
10.1137/S0895480102417379
SODA
Keywords
DocType
Volume
constant distortion,polynomial time approximation scheme,outerplanar graph,approximation ratio,tree metrics,k-Outerplanar Graphs,general metrics,planar grid,approximation algorithm,general planar graph,probabilistic tree embeddings
Conference
20
Issue
ISSN
Citations 
1
0895-4801
18
PageRank 
References 
Authors
1.16
14
5
Name
Order
Citations
PageRank
Chandra Chekuri13493293.51
Anupam Gupta22989210.44
Ilan Newman3114982.18
Yuri Rabinovich4181.16
Alistair Sinclair51506308.40