,
Simon Weber
Creative Commons Attribution 4.0 International license
Schaefer’s dichotomy theorem states that a Boolean constraint satisfaction problem (CSP) is polynomial-time solvable if one of four given conditions holds for every type of constraint allowed in its instances. Otherwise, it is NP-complete. In this paper, we analyze Boolean CSPs in terms of their topological complexity, instead of their computational complexity. Motivated by complexity and topological universality results in computational geometry, we attach a natural topological space to the set of solutions of a Boolean CSP and introduce the notion of projection-universality. We prove that a Boolean CSP is projection-universal if and only if it is categorized as NP-complete by Schaefer’s dichotomy theorem, showing that the dichotomy translates exactly from computational to topological complexity. We show a similar dichotomy for SAT variants and homotopy-universality.
@InProceedings{schnider_et_al:LIPIcs.SoCG.2024.77,
author = {Schnider, Patrick and Weber, Simon},
title = {{A Topological Version of Schaefer’s Dichotomy Theorem}},
booktitle = {40th International Symposium on Computational Geometry (SoCG 2024)},
pages = {77:1--77:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-316-4},
ISSN = {1868-8969},
year = {2024},
volume = {293},
editor = {Mulzer, Wolfgang and Phillips, Jeff M.},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SoCG.2024.77},
URN = {urn:nbn:de:0030-drops-200220},
doi = {10.4230/LIPIcs.SoCG.2024.77},
annote = {Keywords: Computational topology, Boolean CSP, satisfiability, computational complexity, solution space, homotopy universality, homological connectivity}
}