pH Seminar
This online seminar provides the opportunity to engage with cutting-edge research and connect with the pH community!
The pH seminar takes place monthly, usually first Wednesday, 4 pm (CET) via Zoom.
Meeting-ID: 687 5689 8101
Passwort: mV0dd94q
The abstracts and slides of all previous talks can be found on researchseminars.org or here.
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Next Talk
06.05.2026 - 4 pm (CEST) - Carsten Hartmann (BTU Cottbus-Senftenberg)
Title:
Stochastic port-Hamiltonian systems of Langevin-type: realisation of constraints
Abstract:
The realisation of constraints by strong confining forces is a classical theme in mechanics. Recently, there has been a growing interest in studying constrained stochastic differential equations, due to their relevance in molecular dynamics, power network modelling, or machine learning.
In this talk, we will discuss the realisation of algebraic constraints on so-called underdamped Langevin systems that are a special kind of stochastic port-Hamiltonian systems, the key property being that the noise coefficient is degenerate and acts only on those states that are subject to friction. Physically, constraints can be realised by different mechanisms, such as strong forces or large friction, but also small or large masses. We will discuss limit theorems for several of these confinement mechanisms from both physical and mathematical perspective, including quantitative convergence results. It turns out that some of the confinement mechanisms provide uniform-in-time approximations of the limiting differential-algebraic (i.e. constrained) system, but others do not, and we will explain why this observation is relevant for Monte-Carlo sampling of high-dimensional probability distributions.
This is joint work with Lara Neureither (Cottbus) and Upanshu Sharma (Sydney).
References:
[1] Hartmann, C., Neureither, L., & Sharma, U. (2025). Affine constraints in non-reversible diffusions with degenerate noise. arXiv preprint arXiv:2505.00243 (to appear in SIADS).
[2] Hartmann, C., Neureither, L., & Sharma, U. (2026). Realisation of constraints in underdamped Langevin dynamics. arXiv preprint arXiv:2604.02129.
Upcoming Talks
June 03, 2026- Anthony Hastir
July 01, 2026- Antoine Tordeux
Sep 02, 2026- Sebastian Schöps
