,
George B. Mertzios
,
Paul G. Spirakis
Creative Commons Attribution 4.0 International license
In this paper we study two natural models of random temporal graphs. In the first, the continuous model, each edge e is assigned l_e labels, each drawn uniformly at random from (0,1], where the numbers l_e are independent random variables following the same discrete probability distribution. In the second, the discrete model, the l_e labels of each edge e are chosen uniformly at random from a set {1,2,…,T}. In both models we study the existence of δ-temporal motifs. Here a δ-temporal motif consists of a pair (H,P), where H is a fixed static graph and P is a partial order over its edges. A temporal graph 𝒢 = (G,λ) contains (H,P) as a δ-temporal motif if 𝒢 has a simple temporal subgraph on the edges of H whose time labels are ordered according to P, and whose life duration is at most δ. We prove sharp existence thresholds for all δ-temporal motifs, and we identify a qualitatively different behavior from the analogous static thresholds in Erdős-Rényi random graphs. Applying the same techniques, we then characterize the growth of the largest δ-temporal clique in the continuous variant of our random temporal graphs model. Finally, we consider the doubling time of the reachability ball centered on a small set of vertices of the random temporal graph as a natural proxy for temporal expansion. We prove sharp upper and lower bounds for the maximum doubling time in the continuous model.
@InProceedings{austin_et_al:LIPIcs.MFCS.2026.84,
author = {Austin, Henry and Mertzios, George B. and Spirakis, Paul G.},
title = {{Sharp Thresholds for Temporal Motifs and Doubling Time in Random Temporal Graphs}},
booktitle = {51st International Symposium on Mathematical Foundations of Computer Science (MFCS 2026)},
pages = {84:1--84:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-442-0},
ISSN = {1868-8969},
year = {2026},
volume = {386},
editor = {Kouck\'{y}, Michal and Petrișan, Daniela},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2026.84},
URN = {urn:nbn:de:0030-drops-274660},
doi = {10.4230/LIPIcs.MFCS.2026.84},
annote = {Keywords: Random temporal graph, \delta-temporal motif, sharp upper and lower bounds, doubling time}
}