,
Ivor van der Hoog
,
Eva Rotenberg
,
Johanne Müller Vistisen
,
Sampson Wong
Creative Commons Attribution 4.0 International license
We maintain a (1+ε)-spanner over the disk intersection graph of a dynamic set of disks. We restrict all disks to have their diameter in [4,Ψ] for some fixed and known Ψ. The resulting (1+ε)-spanner has size O(n ε^{-2} log Ψ log(ε^{-1})), where n is the present number of disks.
We develop a novel use of persistent data structures to dynamically maintain our (1+ε)-spanner. Our approach requires O(ε^{-2} n log⁴n log Ψ) space and has an O((Ψ/ε)² log⁴n log²Ψ log²(ε^{-1})) expected amortised update time. For constant ε and Ψ, this spanner has near-linear size, uses near-linear space and has polylogarithmic update time. Furthermore, we observe that for any ε < 1, our spanner also serves as a connectivity data structure. With a slight adaptation of our techniques, this leads to better bounds for dynamically supporting connectivity queries in a disk intersection graph. In particular, we improve the space usage when compared to the dynamic data structure of (Baumann et al., DCG'24), replacing the linear dependency on Ψ by a polylogarithmic dependency. Finally, we generalise our results to d-dimensional hypercubes.
@InProceedings{deberg_et_al:LIPIcs.ESA.2026.52,
author = {de Berg, Sarita and van der Hoog, Ivor and Rotenberg, Eva and Vistisen, Johanne M\"{u}ller and Wong, Sampson},
title = {{A Dynamic (1+\epsilon)-Spanner for Disk Intersection Graphs}},
booktitle = {34th Annual European Symposium on Algorithms (ESA 2026)},
pages = {52:1--52:23},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-445-1},
ISSN = {1868-8969},
year = {2026},
volume = {388},
editor = {Bille, Philip and Pettie, Seth and Storandt, Sabine},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ESA.2026.52},
URN = {urn:nbn:de:0030-drops-271880},
doi = {10.4230/LIPIcs.ESA.2026.52},
annote = {Keywords: intersection graphs, dynamic data structures, spanners}
}