Organizers: Bettina Keller

Abstract: 

This minisymposium focuses on modern AI and machine learning methods for representing, understanding, and simulating complex dynamical systems, with particular relevance to the multiscale challenges addressed within CRC 1114. The session highlights methodological developments that bridge data-driven learning and mathematical modelling and capture essential structures in high-dimensional, stochastic, and multiscale dynamics.

Organizers: Carsten Hartmann, Sebastian Reich

Abstract:

Generative diffusion models can transform a data distribution to noise and remove the noise by a reverse transformation to obtain new data with a distribution similar to the original one; they offer state of the art performance in generative AI for images. Normalizing Flows are deterministic or stochastic generative models that  produce tractable distributions where both sampling and parameter estimation can be exact or efficient; they have strong connections to data assimilation and optimal control. The goal of this minisymposium is to survey recent progress in the aforementioned fields of research and to discuss connections between them. A particular focus is on the application to multiscale problems and stochastic control.

Organizers: Marita Thomas, Timm John

Part A: 

Processes at fluid–solid interfaces fundamentally control mass transfer, reaction kinetics, and permeability evolution in geological materials.

This session focuses on the modeling and mathematical methods for pore-scale mechanisms including fluid-solid element exchange, moving boundary problems during dissolution and precipitation, and fluid liberation from hydrous minerals during metamorphic reactions. Particular attention is given to fluid flow in low-porosity systems and transport in confined geometries, where capillarity, surface energy, and reactive interface dynamics dominate.

Part B: 

Large-scale geodynamic behavior emerges from the interplay between deformation, rheology, and multiphase flow. This session addresses the modeling and mathematical methods with a focus on mechanical aspects of fluid-bearing rocks, including viscous, plastic, and brittle regimes of large scale deformations. This includes two-phase flow systems with dynamically evolving porosity-permeability relationships and feedbacks between compaction, dilation, and fluid pressure.

Organizers: Ana Djurdjevac, Nicolas Perkowski, Rupert Klein

Abstract:

Interacting particle systems serve as powerful and versatile models across various domains, including molecular dynamics, biology, and social sciences. While these systems oer rich modeling capabilities, their analytical and computational complexity grows rapidly with the number of particles. A common approach to overcome this challenge is to derive eective equations for the empirical particle density. This mini-symposium focuses on the derivation and analysis of nonlinear SPDEs that describe uctuations in particle systems. Key topics will include various SPDEs arising from such uctuation descriptions, along with their well-posedness and the error with respect to the particle system.

Organizers: Rupert Klein, Sebastian Reich, Daniel Baum, Stephan Pfahl

This minisymposium is split into two parts:

A: Persistent patterns in atmospheric flows: Heat Waves and atmospheric blockings

B: Persistent patterns in atmospheric flows: Fronts and Vortices

Significant atmospheric phenomena, such as fronts, cyclones, and heat waves, stand out amongst the daily ups and downs of the weather. They are well recognizeable owing to their specific spatial structure and their longevity relative to the ubiquitous much faster transients associated, e.g., with the convection and turbulent processes that constitute them. They are "persistent" in this sense, and it is this persistence that makes these structures identifiable in observational or simulation data and particularly accessible to theoretical analysis, efficient numerical approximation, and data-based tracking or modelling. This minisymposium collects reports from such diverse approaches towards improved scientific understanding of these often severe weather patterns.

Organizers: Luigi Delle Site, Cecilia Clementi, Sara Jand

Abstract:

Molecular modeling based on electronic properties assures the inclusion into effective models of the intrinsic quantum nature of atoms and molecules. The resulting models assure a high computational efficiency in treating large systems for long time with the minimal lost of microscopic accuracy and eventually to go back to the electronic scale. The corresponding scaling up and down of physical accuracy allows to identify the interconnection between different scales and as a consequence to pin point the relevant degrees of freedom that drive properties of systems of interest.  In this minisymposium we will see techniques and applications that realize the idea above.

Organizers: Thomas Eiter, Marita Thomas, Martin Heida

Abstract:

In many problems from material science, geophysics and fluid dynamics, certain material or geometrical properties vary strongly on a local scale. To study their effect on the macroscopic behavior and to obtain effective models, one can derive averaged equations by passage to a homogenized framework. Moreover, by introducing some randomness, one can take into account that the exact distribution of the small-scale fluctuations is usually unknown in applications. This minisymposium brings together experts on the mathematical investigation of such stochastic homogenization problems

Organizers: Marcus Weber

Abstract:

In an era defined by data abundance and complexity, the question of where to sample becomes as critical as how. This minisymposium explores the nuanced interplay between spatial, temporal, and structural dimensions in sampling strategies for complex systems. Speakers will examine adaptive, probabilistic, and machine learning–driven approaches that optimize representativeness, efficiency, and insight. Emphasis will be placed on the challenges of heterogeneity, uncertainty, and evolving system behavior. The symposium aims to foster cross-disciplinary dialogue and spark innovation in the artful science of sampling.

Organizers: Stefanie Winkelmann, Maximilian Engel

Abstract:

Interacting particle systems appear in physics, biology, and social dynamics, often leading to high-dimensional models. This minisymposium focuses on recent advances in model reduction techniques that enable efficient simulation, analysis, and interpretation of such systems. Approaches include mean-field models and stochastic PDEs, transfer-operator frameworks and Markov state models, hybrid multiscale models, coherent structure analysis, as well as data-driven techniques. The session aims to bring together theoretical and applied perspectives on efficient representations of complex, many-body systems.

Organizers: Luigi Delle Site, Carsten Hartmann

Abstract:

The accurate calculation of (relative) free energies is one of the key problems in statistical mechanics. For example, the calculation of interface free energies in situations when there is strong coupling between subsystems can become computationally infeasible by standard thermodynamic integration or particle insertion methods. On the other hand, being able to quantify system-environment interactions is crucial to determine, e.g., the minimum size of a simulation box in a molecular dynamics simulation or to assess the degree on non-Markovianity under coarse-graining. This minisymposium aims at discussing both computational and theoretical challenges related to the micro-macro passage in particle systems. A particular focus will be on estimating thermodynamic potentials and quantifying finite size and memory effects.