Perfect Matching in Random Graphs is as Hard as Tseitin

We study the complexity of proving that a sparse random regular graph on an odd number of vertices does not have a perfect matching, and related problems involving each vertex being matched some pre-specified number of times. We show that this requires proofs of degree $\Omega(n / \log n)$ in the Po...

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Main Authors: Per Austrin, Kilian Risse
Format: Article
Language:English
Published: TheoretiCS Foundation e.V. 2022-12-01
Series:TheoretiCS
Subjects:
Online Access:https://theoretics.episciences.org/9012/pdf
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author Per Austrin
Kilian Risse
author_facet Per Austrin
Kilian Risse
author_sort Per Austrin
collection DOAJ
description We study the complexity of proving that a sparse random regular graph on an odd number of vertices does not have a perfect matching, and related problems involving each vertex being matched some pre-specified number of times. We show that this requires proofs of degree $\Omega(n / \log n)$ in the Polynomial Calculus (over fields of characteristic $\ne 2$) and Sum-of-Squares proof systems, and exponential size in the bounded-depth Frege proof system. This resolves a question by Razborov asking whether the Lov\'asz-Schrijver proof system requires $n^\delta$ rounds to refute these formulas for some $\delta > 0$. The results are obtained by a worst-case to average-case reduction of these formulas relying on a topological embedding theorem which may be of independent interest.
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spelling doaj.art-35253e7d95504ac0bec3a7362c7737b92024-02-02T12:31:07ZengTheoretiCS Foundation e.V.TheoretiCS2751-48382022-12-01Volume 110.46298/theoretics.22.29012Perfect Matching in Random Graphs is as Hard as TseitinPer AustrinKilian RisseWe study the complexity of proving that a sparse random regular graph on an odd number of vertices does not have a perfect matching, and related problems involving each vertex being matched some pre-specified number of times. We show that this requires proofs of degree $\Omega(n / \log n)$ in the Polynomial Calculus (over fields of characteristic $\ne 2$) and Sum-of-Squares proof systems, and exponential size in the bounded-depth Frege proof system. This resolves a question by Razborov asking whether the Lov\'asz-Schrijver proof system requires $n^\delta$ rounds to refute these formulas for some $\delta > 0$. The results are obtained by a worst-case to average-case reduction of these formulas relying on a topological embedding theorem which may be of independent interest.https://theoretics.episciences.org/9012/pdfcomputer science - computational complexityf.2.2f.1.3i.2.3f.4.1
spellingShingle Per Austrin
Kilian Risse
Perfect Matching in Random Graphs is as Hard as Tseitin
TheoretiCS
computer science - computational complexity
f.2.2
f.1.3
i.2.3
f.4.1
title Perfect Matching in Random Graphs is as Hard as Tseitin
title_full Perfect Matching in Random Graphs is as Hard as Tseitin
title_fullStr Perfect Matching in Random Graphs is as Hard as Tseitin
title_full_unstemmed Perfect Matching in Random Graphs is as Hard as Tseitin
title_short Perfect Matching in Random Graphs is as Hard as Tseitin
title_sort perfect matching in random graphs is as hard as tseitin
topic computer science - computational complexity
f.2.2
f.1.3
i.2.3
f.4.1
url https://theoretics.episciences.org/9012/pdf
work_keys_str_mv AT peraustrin perfectmatchinginrandomgraphsisashardastseitin
AT kilianrisse perfectmatchinginrandomgraphsisashardastseitin