,
Yash Pote
,
Jonathan Scarlett
,
Joy Qiping Yang
Creative Commons Attribution 4.0 International license
We introduce the problem of entropy equivalence testing for probability distributions, a relaxation of the well-studied closeness testing problem, where the distribution testing algorithm is now only required to distinguish, given samples from two unknown distributions p,q and a parameter ε ∈ (0,1/2], between p = q and |H(p)-H(q)| ⩾ ε (where H denotes the Shannon entropy). We provide a time- and sample-efficient algorithm for this task, showing that the optimal sample complexity for this task can be significantly lower than that of closeness testing. As an application, we leverage this result to provide the first non-trivial testing algorithm for (standard) closeness of low-degree Bayesian networks, which significantly improves on either the sample or time complexity of a baseline based on full learning.
@InProceedings{canonne_et_al:LIPIcs.APPROX/RANDOM.2026.50,
author = {Canonne, Cl\'{e}ment L. and Pote, Yash and Scarlett, Jonathan and Yang, Joy Qiping},
title = {{Entropy Equivalence Testing}},
booktitle = {Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques (APPROX/RANDOM 2026)},
pages = {50:1--50:23},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-449-9},
ISSN = {1868-8969},
year = {2026},
volume = {392},
editor = {Singh, Mohit and Gur, Tom},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.APPROX/RANDOM.2026.50},
URN = {urn:nbn:de:0030-drops-277676},
doi = {10.4230/LIPIcs.APPROX/RANDOM.2026.50},
annote = {Keywords: Entropy, distribution testing, sublinear algorithm, Bayesian network}
}