ERIK MCLEAN / UNSPLASH

Physikalisches Kolloquium

Friday, 10. May 2024 5:00 pm  Machines that Learn via Physical Dynamics

Prof. Dr. Florian Marquardt, Institut für Theoretische Physik, Universität Erlangen

Recent rapid progress in applications of machine learning has also illustrated that there is an exponential growth of required resources, especially for advanced applications like large-language models. This makes it all the more urgent to explore possible alternatives to current digital artificial neural networks. The field of neuromorphic computing sets itself the goal to identify suitable physical architectures that enable us to perform machine learning tasks in a highly parallel and much more energy-efficient manner. In this talk, I will present two examples from our research in this domain. One important goal is physics-based training. I will introduce the idea of Hamiltonian Echo Backpropagation, which allows to perform both a physics-based version of backpropagation and parameter updates purely via physical dynamics, making it unique among proposed physical learning techniques. In the second part, I will present our recent idea on implementing fully nonlinear neuromorphic computing based on any purely linear wave scattering platform.

Self-Learning Machines Based on Hamiltonian Echo Backpropagation, Víctor López-Pastor and Florian Marquardt, Phys. Rev. X 13, 031020 (2023) https://journals.aps.org/prx/abstract/10.1103/PhysRevX.13.031020

Fully Non-Linear Neuromorphic Computing with Linear Wave Scattering, Clara C. Wanjura, Florian Marquardt, arXiv:2308.16181 https://arxiv.org/abs/2308.16181

Particle Colloquium

The Triplet Track Trigger Concept for the FCC-hh

Dr. Tamasi Kar, Physikalisches Institut Universität Heidelberg

Astronomy colloquium

Tuesday, 7. May 2024 4:30 pm  Deciphering the properties and impact of hot and massive stars with detailed stellar atmosphere modelling

Dr Andreas Sander, Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg Massive stars are astrophysical keystones, shaping our cosmic history. As the progenitors of neutron stars and black holes, massive stars reach all nuclear burning stages and - before eventually collapsing - greatly enrich their surrounding medium with momentum, matter, and ionizing radiation. This feedback of massive stars is a building block for the evolution of galaxies, initiating and inhibiting further star formation. In the "afterlives" of massive stars, black holes and neutron stars can merge with each other, giving rise a to Gravitational Wave events. Yet, the overall picture of massive stars we draw in textbooks is rather sketchy and new observational frontiers such as the strong metal-enrichment in high-redshift galaxies discovered by JWST or the black hole statistics obtained from Gravitational Waves only add further pieces to the engmatic massive star puzzle. For a better understanding of massive stars, it is essential to properly determine their parameters and feedback. For young and hot massive stars, many properties are only accessible via spectroscopy. Their quantitative measurements and predictions rely on suitable models for stellar atmospheres, which requires sophisticated simulations to account for their non-equilibrium conditions and strong stellar winds. In this talk, I will introduce the techniques and challenges of atmosphere modelling for hot, massive stars and their winds. Afterwards, I will present a selection of the research efforts within my group demonstrating the range of empirical and theoretical applications of modern non-LTE stellar atmosphere models, such as the analysis of important landmarks of massive star evolution, the search for "hidden" post-interaction binaries, or theoretical insights on radiation-driven winds. Those unable to attend the colloquium in person are invited to participate online through Zoom (Meeting ID: 942 0262 2849, passcode 792771) using the link: https://eu02web.zoom-x.de/j/94202622849?pwd=dGlPQXBiUytzY1M2UE5oUDRhbzNOZz09

Center for Quantum Dynamics Colloquium

Wednesday, 8. May 2024 2:00 pm  Tracking the confinement-induced hybridization of the Higgs mode in a strongly interacting superfluid

Dr. Cesar Cabrera, Institute for Quantum Physics, Universität Hamburg