,
Yuval Nidam
,
Rachel Saban
,
Micha Sharir
Creative Commons Attribution 4.0 International license
Let P be a set of n points in ℝ^d, d ≥ 2, and let t ≥ 2 be an integer. Let H_t(P) denote the t-uniform hypergraph on P, whose hyperedges consist of all t-tuples T ⊂ P for which ‖p-q‖ ≤ 1, for any two points p,q ∈ T. A matching in H_t(P) is a collection of vertex-disjoint hyperedges. We present a PTAS for finding a maximum matching in H_t(P). In particular, we present the first PTAS for the well-studied problem known as maximum (vertex-disjoint) triangle packing in unit disk graphs. Our approach consists of a sparsification stage, which replaces P by a subset Q with favorable properties, followed by an implementation of a PTAS for a maximum matching in H_t(Q). The two stages follow the high-level machinery in [Édouard Bonnet et al., 2023] and [Rom Aschner et al., 2013], respectively, but are considerably more involved.
@InProceedings{katz_et_al:LIPIcs.ESA.2026.48,
author = {Katz, Matthew J. and Nidam, Yuval and Saban, Rachel and Sharir, Micha},
title = {{Matching in Geometric Uniform Hypergraphs}},
booktitle = {34th Annual European Symposium on Algorithms (ESA 2026)},
pages = {48:1--48:15},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-445-1},
ISSN = {1868-8969},
year = {2026},
volume = {388},
editor = {Bille, Philip and Pettie, Seth and Storandt, Sabine},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ESA.2026.48},
URN = {urn:nbn:de:0030-drops-271848},
doi = {10.4230/LIPIcs.ESA.2026.48},
annote = {Keywords: Geometric hypergraphs, maximum matching, PTAS, sparsification, local search}
}