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Gerrit Wellecke

Publications and source records attributed to Gerrit Wellecke.

4 recordsLinked to original sources

Improving the prediction of spatio-temporal chaos by combining parallel reservoir computing with dimensionality reduction

Reservoir computers can be used to predict time series generated by spatio-temporal chaotic systems. Using multiple reservoirs in parallel has shown improved performances for these predictions, by effectively reducing the input dimensionality of each reservoir. Similarly, one may further reduce the dimensionality of the input data by transforming to a lower-dimensional latent space. Combining both approaches, we show that using dimensionality-reduced latent space predictions for parallel reservoir computing not only reduces computational costs, but also leads to better prediction results for small to medium reservoir sizes. In the combined approach we further demonstrate that dimensionality reduction improves small-reservoir predictions regardless of noise contaminating the training data. The benefit of dimensionality-reduced parallel reservoir computing is illustrated and evaluated on the basis of the prediction of the one-dimensional Kuramoto-Sivashinsky equation.

nlin.CD

Binding and dimerization control phase separation in a compartment

Biological cells exhibit a hierarchical spatial organization, where various compartments harbor condensates that form by phase separation. Cells can control the emergence of these condensates by affecting compartment size, the amount of the involved molecules, and their physical interactions. While physical interactions directly affect compartment binding and phase separation, they can also cause oligomerization, which has been suggested as a control mechanism. Analyzing an equilibrium model, we illustrate that oligomerization amplifies compartment binding and phase separation, which reinforce each other. This nonlinear interplay can also induce multistability, which provides additional potential for control. Our work forms the basis for deriving thermodynamically consistent kinetic models to understand how biological cells can regulate phase separation in their compartments.

physics.bio-ph

Hackathons for biophysics education: simulating the cytoskeleton

Hackathons are intensive innovation-oriented events where participants work in teams to solve problems or create projects in as little as 24 or 48 hours. These events are common in startup culture, open source communities and mainstream industry. Here we examine how hackathons can be ported to academic teaching, specifically in computational biophysics. We propose hackathons as a teaching modality distinct from traditional courses and structured workshops. In particular, we suggest they can offer a low-stakes platform for students to overcome entry barriers to computational tools or to explore new topics, disciplines, and skills beyond their academic comfort zone. We tested this format in two computational biophysics hackathons on the Göttingen campus in 2023 and 2024, providing practical insights and a preliminary evaluation. To the best of our knowledge, the 2024 event is the first public hackathon dedicated to Biophysics. This paper explores the benefits of the hackathon format for teachers and researchers and provides guidelines for running a hackathon adapted to a teaching goal.

physics.ed-ph

Asymmetric Thermal Relaxation in Driven Systems: Rotations go Opposite Ways

It was predicted and recently experimentally confirmed that systems with microscopically reversible dynamics in locally quadratic potentials warm up faster than they cool down. This thermal relaxation asymmetry challenged the local-equilibrium paradigm valid near equilibrium. Because the intuition and proof hinged on the dynamics obeying detailed balance, it was not clear whether the asymmetry persists in systems with irreversible dynamics. To fill this gap, we here prove the relaxation asymmetry for systems driven out of equilibrium by a general linear drift. The asymmetry persists due to a non-trivial isomorphism between driven and reversible processes. Moreover, rotational motions emerge that, strikingly, occur in opposite directions during heating and cooling. This highlights that noisy systems do not relax by passing through local equilibria.

cond-mat.stat-mech