License: Creative Commons Attribution 3.0 Unported license (CC BY 3.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ICALP.2020.101
URN: urn:nbn:de:0030-drops-125082
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2020/12508/
Go to the corresponding LIPIcs Volume Portal

Wahlström, Magnus

On Quasipolynomial Multicut-Mimicking Networks and Kernelization of Multiway Cut Problems

pdf-format:
LIPIcs-ICALP-2020-101.pdf (0.5 MB)

Abstract

We show the existence of an exact mimicking network of k^O(log k) edges for minimum multicuts over a set of terminals in an undirected graph, where k is the total capacity of the terminals. Furthermore, if Small Set Expansion has an approximation algorithm with a ratio slightly better than Θ(log n), then a mimicking network of quasipolynomial size can be computed in polynomial time. As a consequence of the latter, several problems would have quasipolynomial kernels, including Edge Multiway Cut, Group Feedback Edge Set for an arbitrary group, 0-Extension for integer-weighted metrics, and Edge Multicut parameterized by the solution and the number of cut requests. The result works via a combination of the matroid-based irrelevant edge approach used in the kernel for s-Multiway Cut with a recursive decomposition and sparsification of the graph along sparse cuts. The main technical contribution is a matroid-based marking procedure that we can show will mark all non-irrelevant edges, assuming that the graph is sufficiently densely connected. The only part of the result that is not currently constructive and polynomial-time computable is the detection of such sparse cuts.
This is the first progress on the kernelization of Multiway Cut problems since the kernel for s-Multiway Cut for constant value of s (Kratsch and Wahlström, FOCS 2012).

BibTeX - Entry

@InProceedings{wahlstrm:LIPIcs:2020:12508,
  author =	{Magnus Wahlstr{\"o}m},
  title =	{{On Quasipolynomial Multicut-Mimicking Networks and Kernelization of Multiway Cut Problems}},
  booktitle =	{47th International Colloquium on Automata, Languages, and Programming (ICALP 2020)},
  pages =	{101:1--101:14},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-138-2},
  ISSN =	{1868-8969},
  year =	{2020},
  volume =	{168},
  editor =	{Artur Czumaj and Anuj Dawar and Emanuela Merelli},
  publisher =	{Schloss Dagstuhl--Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/opus/volltexte/2020/12508},
  URN =		{urn:nbn:de:0030-drops-125082},
  doi =		{10.4230/LIPIcs.ICALP.2020.101},
  annote =	{Keywords: Multiway Cut, Kernelization, Small Set Expansion, Mimicking Networks}
}

Keywords: Multiway Cut, Kernelization, Small Set Expansion, Mimicking Networks
Collection: 47th International Colloquium on Automata, Languages, and Programming (ICALP 2020)
Issue Date: 2020
Date of publication: 29.06.2020

DROPS-Home | Fulltext Search | Imprint | Privacy Published by LZI