ICM 2026 Invited Section Lecture – Fabio Martinelli

ICM 2026 Invited Section Lecture – Fabio Martinelli

🎙 Fabio Martinelli 👥 61K 📅 October 6, 2026 ⏱ 41 min 👁 389 📄 expert opinion 🧭 2026-10-16
Available in: English (current) Français

Keywords

KCMbootstrap percolationuniversality classesglassy dynamicstime scales

Summary

The talk presents a comprehensive overview of recent advances in the study of kinetically constrained models (KCMs) and their connection to bootstrap percolation. Although KCMs have a trivial equilibrium product measure, they exhibit rich glassy dynamics due to hard kinetic constraints. The speaker explains the general framework, highlighting examples such as the Frederickson-Andersen and East models. A central focus is the universality problem: classifying two-dimensional update families into classes that share the same divergence of the mean hitting time when the vacancy density tends to zero. The talk reviews the three bootstrap percolation universality classes (supercritical, critical, subcritical) and then introduces new results for KCMs. Key findings include a distinction between rooted and unrooted supercritical families, leading to exponential time scales of order beta or beta^2 respectively. For critical families, the exponent in the time scale can double compared to bootstrap percolation depending on whether the set of stable directions is finite or infinite. The speaker gives heuristic arguments, such as the propagation of mobile droplets in the Duarte model, to explain these exponents. The lecture concludes with sharp results and mentions open problems.

184 words

Critical Evaluation

Value of the Information & Strength of the Argument

The talk provides a high-value synthesis of a challenging area, bridging statistical mechanics and probability. The argumentation is rigorous, relying on precise theorem statements and references to recent papers. The speaker effectively contrasts KCM behavior with that of bootstrap percolation, using careful examples and heuristic explanations that clarify the underlying mechanisms. The logical progression from definitions to universality results is well-structured, emphasizing why KCMs require novel treatment of energy barriers and droplet motion. The depth of mathematical reasoning is strong, and the presentation of exact asymptotic constants for representative models adds substantial value.

Scientific Rigor, Source Quality, Title Accuracy

The talk exhibits high scientific rigor, citing the original works of Balogh, Bollobás, Morris, and others, as well as recent collaborations of the speaker. The theoretical results are supported by proof sketches and references to published literature. The title accurately captures the lecture’s scope, which is indeed an invited section lecture focusing on universality for two-dimensional kinetically constrained spin models. No advertising or sponsored content is present. No audience comments were provided for analysis.

182 words

Title / Content Match

The title correctly reflects the content, which is a detailed presentation of universality results for two-dimensional kinetically constrained spin models.

Quality & Reliability

8/10

Invited lecture at ICM 2026, presented by an established researcher, with rigorous mathematical content and clear structure. The talk is based on published, peer-reviewed research and collaborations with leading probabilists.

Key Moments

Contribution & Novelties

The talk presents novel universality results for KCMs, extending the bootstrap percolation classification and highlighting the non-trivial role of energy barriers. It offers a systematic way to predict time-scale divergences based on rootedness and the finite/infinite nature of stable directions. This contributes to a deeper understanding of glassy dynamics and many-body localization.

Pour aller plus loin :

  • Bootstrap percolation — Background on the monotone cellular automaton that is tightly related to KCMs.
  • Universality (physics) — Concept of universality classes, essential to understanding the talk’s unifying framework.
  • Many-body localization — A phenomenon inspired by KCMs, mentioned in the description as a motivation for quantum spin chains.

105 words

Radar Profile

The profile shows exceptional technical depth and information density, with consistently high scores across all dimensions. The slightly lower but still strong reliability score reflects the expertise of the speaker and the rigorous nature of the presentation. This is a dense, specialized talk aimed at a mathematically sophisticated audience.

Reliability 9/10