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RMK Darmstadt

Rhein-Main-Kolloquium

Date: 13.02.2026

Time: 15:15–18:00 h

Quirin Vogel: Title: Loop Representations for the Bose Gas

Abstract: The Bose gas is a fundamental model in quantum statistical mechanics. It admits a representation in terms of interacting Brownian bridges. We review this connection and discuss the connection between condensation and the appearance of long loops/random interlacements. We also review some progress made recently for the interacting Bose gas concerning Gibbs measures and large deviations.

 

 Maximilian Fels: Titel: Gaussian Free Field Subject to a Hard Wall

Abstract: The Discrete Gaussian Free Field (DGFF) serves as a canonical model for random interfaces in statistical mechanics. When conditioned to stay non-negative on a domain—an event known as the "hard wall" constraint—the field undergoes entropic repulsion, lifting away from the wall to accommodate its fluctuations. The study of this phenomenon in two dimensions was pioneered by Bolthausen, Deuschel, and Giacomin (2001), who established the leading-order asymptotics for the probability of the hard wall event. In this talk, I will present two major recent advancements that significantly refine our understanding of this problem: The Binary Tree (Fels, Hartung, Louidor 2024): We first discuss the case of the DGFF on the binary tree, where the hierarchical structure permits a complete derivation of the conditioned field's behavior. We will show that the hard wall constraint leads to a repulsion profile that makes the conditioned law asymptotically mutually singular with respect to the unconditioned law. The 2D Plane (Fels, Louidor, Wu 2026): Turning to the Euclidean lattice $\mathbb{Z}^2$, I will present very recent work that improves upon the classical BDG result by capturing the subleading order of the probability asymptotics. The analysis relies on a novel orthogonal decomposition of the field into a "constant" component and a conditioned remainder, handled via multi-scale analysis and double-exponential tail bounds.

Speakers

Quirin Vogel, Universität Klagenfurt
Maximilian Fels, Universität zu Köln

Place

S2|15 Raum 244
Schlossgartenstraße 7, 64289 Darmstadt

Organizers

Technische Universität Darmstadt

Fachbereich Mathematik - Stochastik
Schlossgartenstraße 7
64289 Darmstadt
Telefon: +49 6151 16-23380
Telefax: +49 6151 16-23381
info(at)stochastik-rhein-mainde


Organizing partners

Goethe-Universität Frankfurt am Main, Johannes Gutenberg-Universität Mainz, Justus-Liebig-Universität Gießen

For this event, no registration is necessary. PDF- Link