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The online stochastic matching problem was introduced by [Feldman et al., 2009], together with the (1-1/e)-competitive Suggested Matching algorithm. In the most general edge-weighted setting, this ratio has not been improved for more than one decade, until recently [Yan, 2024] beat the 1-1/e bound and [Qiu et al., 2023] further improved it to 0.650. Both works measure the online competitiveness against the offline LP relaxation introduced by Jaillet and Lu [Jaillet and Lu, 2014]. The same LP has also played an important role in other settings as it is a natural choice for two-choice online algorithms. In this paper, we prove an upper bound of 0.663 and a lower bound of 0.662 for edge-weighted online stochastic matching under Jaillet-Lu LP. We propose a simple hard instance and identify the optimal online algorithm for this specific instance which has a competitive ratio of < 0.663. Despite the simplicity of the instance, we then show that a near-optimal algorithm for it, which has a competitive ratio of > 0.662, can be generalized to work on all instances without any loss. As our algorithm is generalized from a real near-optimal algorithm instead of manually combining trivial strategies, it has two natural advantages compared with previous works: (1) its matching strategy varies from time to time; (2) it utilizes global information about offline vertices. On the other hand, the upper bound suggests that more powerful LPs and multiple-choice strategies are needed if we want to further improve the ratio by > 0.001. In addition to our main result, we also generalize the asymptotic equivalence between the Poisson arrival model and the original online stochastic matching established by [Huang and Shu, 2021], removing the requirement of approximate monotonicity for the online algorithm.
@InProceedings{yan:LIPIcs.ICALP.2026.156,
author = {Yan, Shuyi},
title = {{Edge-Weighted Online Stochastic Matching Under Jaillet-Lu LP}},
booktitle = {53rd International Colloquium on Automata, Languages, and Programming (ICALP 2026)},
pages = {156:1--156:18},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-428-4},
ISSN = {1868-8969},
year = {2026},
volume = {374},
editor = {Bhattacharya, Sayan and Nanongkai, Danupon and Benedikt, Michael and Puppis, Gabriele},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2026.156},
URN = {urn:nbn:de:0030-drops-265450},
doi = {10.4230/LIPIcs.ICALP.2026.156},
annote = {Keywords: Online stochastic matching}
}