Fri, 06 Mar 2026
13:15
L6

Geometric and topological potentials driving self-assembly

Ivan Spirandelli
(University of Potsdam)
Abstract
The assembly of molecular building blocks into functional complexes is a central theme in biology and materials science. In this talk, we showcase the generative and thermodynamically predictive capabilities of a geometric model, the morphometric approach to solvation free energy, applied to spherical particles, tubes, and protein subunits. We demonstrate that this purely geometric description is sufficient to generate biologically relevant structural motifs and identify native nucleation states in simulation.
 
However, relying solely on local geometric fit often leads to optimization challenges. Molecular simulations frequently become trapped in local minima because the model lacks global structural information. To address this, we introduce a global bias based on persistent homology. By incorporating a weighted sum of total persistence as an active potential, we obtain an efficient simulation strategy, significantly increasing success rates. Integrating topological descriptions into energy functions offers a general strategy for overcoming kinetic barriers in molecular simulations, with potential applications in drug design, material development, and the study of complex self-assembly processes.
Thu, 19 Jun 2025

16:00 - 17:00
C1

Unusual transport in odd-diffusive systems

Erik Kalz
(University of Potsdam)
Abstract

Odd systems, characterised by broken time-reversal or parity symmetry, 
exhibit striking transport phenomena due to transverse responses. In this 
talk, I will introduce the concept of odd diffusion, a generalisation of 
diffusion in two-dimensional systems that incorporates antisymmetric tensor 
components. Focusing on systems of interacting particles, I adapt a 
geometric approach to derive effective transport equations and show how 
interactions give rise to unusual transport in odd systems. I present 
effects like enhanced self-diffusion, reversed Hall drift and even absolute 
negative mobility that solely originate in odd diffusion. These results 
reveal how microscopic symmetry-breaking gives rise to emergent, equilibrium 
and non-equilibrium transport, with implications for soft matter, chiral 
active systems, and topological materials.

 

Further Information

Erik Kalz is a PhD student at U Potsdam in the group of Ralf Metzler. The group focuses on nonequilibrium statistical physics and anomalous stochastic processes, with applications to biological and soft matter systems.

Mon, 22 Feb 2021
14:15
Virtual

Spaces of metrics of positive scalar curvature on manifolds with boundary

Christian Bär
(University of Potsdam)
Abstract

Unlike for closed manifolds, the existence of positive scalar curvature (psc) metrics on connected manifolds with
nonempty boundary is unobstructed. We study and compare the spaces of psc metrics on such manifolds with various
conditions along the boundary: H ≥ 0, H = 0, H > 0, II = 0, doubling, product structure. Here H stands for the
mean curvature of the boundary and II for its second fundamental form. "Doubling" means that the doubled metric
on the doubled manifold (along the boundary) is smooth and "product structure" means that near the boundary the
metric has product form. We show that many, but not all of the obvious inclusions are weak homotopy equivalences.
In particular, we will see that if the manifold carries a psc metric with H ≥ 0, then it also carries one which is
doubling but not necessarily one which has product structure. This is joint work with Bernhard Hanke.

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