,
Melvin Kallmayer
,
Alexander Leonhardt
,
Ulrich Meyer
,
Ryan O'Connor
,
Manuel Penschuck
Creative Commons Attribution 4.0 International license
The Fixed Degree Sequence Model (FDSM) asks for a uniform sample from the set of all simple graphs that match a prescribed degree sequence. It is typically implemented using Markov-Chain Monte-Carlo (MCMC) processes, such as Edge Switching or Curveball (and their variants). Yet despite decades of research, rigorous bounds on the mixing times of such processes remain impractical. Consequently, several experimental techniques have been used to derive "empirical lower bounds" on the mixing time. We address the following research questions: (1) Which commonly studied graph-theoretic properties serve as reliable empirical predictors for mixing of FDSM MCMC processes? (2) At what structural scales do these properties operate primarily (i. e., are they predominantly local or global in nature)? (3) How can these properties be characterised and quantified most effectively? To this end, we propose Claim, a novel systematic method to establish empirical lower bounds using learnt classifiers, and compare it to existing methods. Apart from interesting insights into the usage of machine learning for this problem, we also derive robust graph properties with respect to different randomisation algorithms. Although experimental in nature, these results may influence both theorist’s and algorithm engineer’s work on improved bounds and better algorithm respectively.
@InProceedings{ajwani_et_al:LIPIcs.SEA.2026.2,
author = {Ajwani, Deepak and Kallmayer, Melvin and Leonhardt, Alexander and Meyer, Ulrich and O'Connor, Ryan and Penschuck, Manuel},
title = {{Different Scales of Randomness: Empirical Mixing Times of the Edge Switching and Curveball MCMC}},
booktitle = {24th International Symposium on Experimental Algorithms (SEA 2026)},
pages = {2:1--2:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-422-2},
ISSN = {1868-8969},
year = {2026},
volume = {371},
editor = {Aum\"{u}ller, Martin and Finocchi, Irene},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SEA.2026.2},
URN = {urn:nbn:de:0030-drops-260062},
doi = {10.4230/LIPIcs.SEA.2026.2},
annote = {Keywords: Mixing Time, Graph Randomization, Machine Learning, Edge Switching}
}