License: Creative Commons Attribution 4.0 International license (CC BY 4.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.APPROX/RANDOM.2023.51
URN: urn:nbn:de:0030-drops-188761
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Hecht, Yahli ; Minzer, Dor ; Safra, Muli

NP-Hardness of Almost Coloring Almost 3-Colorable Graphs

LIPIcs-APPROX51.pdf (0.7 MB)


A graph G = (V,E) is said to be (k,δ) almost colorable if there is a subset of vertices V' ⊆ V of size at least (1-δ)|V| such that the induced subgraph of G on V' is k-colorable. We prove that for all k, there exists δ > 0 such for all ε > 0, given a graph G it is NP-hard (under randomized reductions) to distinguish between:
1) Yes case: G is (3,ε) almost colorable.
2) No case: G is not (k,δ) almost colorable. This improves upon an earlier result of Khot et al. [Irit Dinur et al., 2018], who showed a weaker result wherein in the "yes case" the graph is (4,ε) almost colorable.

BibTeX - Entry

  author =	{Hecht, Yahli and Minzer, Dor and Safra, Muli},
  title =	{{NP-Hardness of Almost Coloring Almost 3-Colorable Graphs}},
  booktitle =	{Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2023)},
  pages =	{51:1--51:12},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-296-9},
  ISSN =	{1868-8969},
  year =	{2023},
  volume =	{275},
  editor =	{Megow, Nicole and Smith, Adam},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{},
  URN =		{urn:nbn:de:0030-drops-188761},
  doi =		{10.4230/LIPIcs.APPROX/RANDOM.2023.51},
  annote =	{Keywords: PCP, Hardness of approximation}

Keywords: PCP, Hardness of approximation
Collection: Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2023)
Issue Date: 2023
Date of publication: 04.09.2023

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