,
Vishvajeet N
Creative Commons Attribution 4.0 International license
We give a deterministic polynomial-time approximation scheme (FPTAS) for the volume of the truncated fractional matching polytope for graphs of maximum degree Δ, where the truncation is by restricting each variable to the interval [0,(1+δ)/Δ], and δ ≤ C/Δ for some constant C > 0. We also generalise our result to the fractional matching polytope for hypergraphs of maximum degree Δ and maximum hyperedge size k, truncated by [0,(1+δ)/Δ] as well, where δ ≤ CΔ^{-(2k-3)/(k-1)}k^{-1} for some constant C > 0. The latter result generalises both the first result for graphs (when k = 2), and a result by Bencs and Regts (2024) for the truncated independence polytope (when Δ = 2). Our approach is based on the cluster expansion technique.
@InProceedings{guo_et_al:LIPIcs.ITCS.2025.57,
author = {Guo, Heng and N, Vishvajeet},
title = {{Deterministic Approximation for the Volume of the Truncated Fractional Matching Polytope}},
booktitle = {16th Innovations in Theoretical Computer Science Conference (ITCS 2025)},
pages = {57:1--57:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-361-4},
ISSN = {1868-8969},
year = {2025},
volume = {325},
editor = {Meka, Raghu},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ITCS.2025.57},
URN = {urn:nbn:de:0030-drops-226858},
doi = {10.4230/LIPIcs.ITCS.2025.57},
annote = {Keywords: deterministic volume computation, cluster expansion, explicit polytopes}
}