@inproceedings{1529fede06f14730ac52e0a29cd502f2,
title = "Exponential resolution lower bounds for weak pigeonhole principle and perfect matching formulas over sparse graphs",
abstract = "We show exponential lower bounds on resolution proof length for pigeonhole principle (PHP) formulas and perfect matching formulas over highly unbalanced, sparse expander graphs, thus answering the challenge to establish strong lower bounds in the regime between balanced constant-degree expanders as in [Ben-Sasson and Wigderson'01] and highly unbalanced, dense graphs as in [Raz'04] and [Razborov'03,'04]. We obtain our results by revisiting Razborov's pseudo-width method for PHP formulas over dense graphs and extending it to sparse graphs. This further demonstrates the power of the pseudo-width method, and we believe it could potentially be useful for attacking also other longstanding open problems for resolution and other proof systems.",
keywords = "Perfect matching, Proof complexity, Resolution, Sparse graphs, Weak pigeonhole principle",
author = "{de Rezende}, {Susanna F.} and Jakob Nordstr{\"o}m and Kilian Risse and Dmitry Sokolov",
year = "2020",
month = jul,
day = "1",
doi = "10.4230/LIPIcs.CCC.2020.28",
language = "English",
series = "Leibniz International Proceedings in Informatics, LIPIcs",
publisher = "Schloss Dagstuhl - Leibniz-Zentrum f{\"u}r Informatik",
editor = "Shubhangi Saraf",
booktitle = "CCC '20: Proceedings of the 35th Computational Complexity Conference 2020",
note = "35th Computational Complexity Conference, CCC 2020 ; Conference date: 28-07-2020 Through 31-07-2020",
}