,
Asif Khan
,
Felix Tschirbs
,
Nils Vortmeier
,
Thomas Zeume
Creative Commons Attribution 4.0 International license
Consider two planar graphs which are subject to edge insertions and deletions. We show that whether the two graphs are isomorphic can be maintained with first-order logic formulas and auxiliary data of polynomial size. This places the dynamic planar graph isomorphism problem into the dynamic descriptive complexity class DynFO. As a consequence, there is a dynamic constant-time parallel algorithm with polynomial-size auxiliary data which maintains whether two dynamic planar graphs are isomorphic.
@InProceedings{datta_et_al:LIPIcs.LICS.2026.36,
author = {Datta, Samir and Khan, Asif and Tschirbs, Felix and Vortmeier, Nils and Zeume, Thomas},
title = {{Dynamic Planar Graph Isomorphism Is in DynFO}},
booktitle = {41st Annual Symposium on Logic in Computer Science (LICS 2026)},
pages = {36:1--36:25},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-434-5},
ISSN = {1868-8969},
year = {2026},
volume = {380},
editor = {Faggian, Claudia and Katoen, Joost-Pieter},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.LICS.2026.36},
URN = {urn:nbn:de:0030-drops-268233},
doi = {10.4230/LIPIcs.LICS.2026.36},
annote = {Keywords: Dynamic complexity theory, parallel computation, dynamic algorithms}
}