# Coarse Differentiation and Multi-flows in Planar Graphs

@article{Lee2008CoarseDA,
title={Coarse Differentiation and Multi-flows in Planar Graphs},
author={James R. Lee and Prasad Raghavendra},
journal={Discrete \& Computational Geometry},
year={2008},
volume={43},
pages={346-362}
}
• Published 2008
• Computer Science, Mathematics
• Discrete & Computational Geometry
AbstractWe show that the multi-commodity max-flow/min-cut gap for series-parallel graphs can be as bad as 2, matching a recent upper bound (Chakrabarti et al. in 49th Annual Symposium on Foundations of Computer Science, pp. 761–770, 2008) for this class, and resolving one side of a conjecture of Gupta, Newman, Rabinovich, and Sinclair.This also improves the largest known gap for planar graphs from $\frac{3}{2}$ to 2, yielding the first lower bound that does not follow from elementary… Expand
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