Report on the seminar “Universality class for driven interfaces and... integrable spin hydrodynamics?” by Kazumasa A. Takeuchi on May 19, 2025

On 19 May 2025, Professor Kazumasa A. Takeuchi (Univ. of Tokyo) gave an iTHEMS hybrid seminar, “Universality class for driven interfaces and… integrable spin hydrodynamics?” He first gave a review of the one-dimensional KPZ universality class, highlighting exact Tracy–Widom statistics, geometry-dependent subclasses, and elegant experiments with electrically driven nematic-liquid-crystal fronts. A “KPZ Huygens principle” was proposed to unify these results. He then unveiled a recent surprise: equilibrium fluctuations of isotropic integrable spin chains display KPZ-type scaling. Two-point correlations match KPZ predictions, though non-2pt quantities are totally different.
Approximately 60 participants, including those on Zoom, attended the seminar, and the Q&A session was lively and engaging.

Reported by Yoshimasa Hidaka