,
Pasin Manurangsi
,
Raghu Meka
,
Warut Suksompong
Creative Commons Attribution 4.0 International license
We consider a setting where we have a ground set ℳ together with real-valued set functions f₁, … , f_n, and the goal is to partition ℳ into two sets S₁,S₂ such that |f_i(S₁) - f_i(S₂)| is small for every i. Many results in discrepancy theory can be stated in this form with the functions f_i being additive. In this work, we initiate the study of the unstructured case where f_i is not assumed to be additive. We show that even without the additivity assumption, the upper bound remains at most O(√{n log n}).
Our result has implications on the fair allocation of indivisible goods. In particular, we show that a consensus halving up to O(√{n log n}) goods always exists for n agents with monotone utilities. Previously, only an O(n) bound was known for this setting.
@InProceedings{hollender_et_al:LIPIcs.ITCS.2026.77,
author = {Hollender, Alexandros and Manurangsi, Pasin and Meka, Raghu and Suksompong, Warut},
title = {{Discrepancy Beyond Additive Functions with Applications to Fair Division}},
booktitle = {17th Innovations in Theoretical Computer Science Conference (ITCS 2026)},
pages = {77:1--77:1},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-410-9},
ISSN = {1868-8969},
year = {2026},
volume = {362},
editor = {Saraf, Shubhangi},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2026.77},
URN = {urn:nbn:de:0030-drops-253641},
doi = {10.4230/LIPIcs.ITCS.2026.77},
annote = {Keywords: Discrepancy Theory, Fair Division}
}