Freitag, 10. Juli 2026 17:00 Uhr KINDERKOLLOQUIUM: Regenbogen, teile Deine Farben!
Selim Jochim, Universität Heidelberg
Selim Jochim, Universität Heidelberg
Prof. Ph.D. Stefan Hollands , Theoretische Physik, Universtät Leipzig Negative Energy Prof. Ph.D. Stefan Hollands Theoretische Physik, Universtät Leipzig Ordinarily, the actual energy is not physically significant but only energy differences are. But in general relativity, the absolute energy (density) appears on the right side of the Einstein equations as a component of the stress tensor. In this colloquium I explore how negative energy densities are thereby related to exotic phenomena such as warp drive spacetimes or wormholes. I outline how quantum fluctuations enable negative energies and can be tiny, e.g. in the halos of black holes, or astronomical, e.g. inside black holes. In many interesting cases, the laws of physics limit the amount of possible negative energy. Such laws, such as the quantum null- or quantum dominant energy conditions, can be seen as a fundamental bridge between gravity and quantum information.
Prof. Dr. Daniel Bemmerer, HZDR Helmholtz Zentrum Dresden Rossendorf Overview of the solar model and LUNANOVA Daniel Bemmerer Helmholtz-Zentrum Dresden-Rossendorf (HZDR) The standard solar model describes the physics of the solar interior. Input parameters include the solar elemental composition, the total energy radiated from the sun, and microphysics such as nuclear reactions and radiation transport. The model can be validated observing the fluxes of neutrinos produced in the solar core and the sound waves at the solar surface. There were two main challenges to the model. First, the solar neutrino problem, which was solved by the discovery of neutrino flavour oscillations. Second, the solar abundance puzzle, caused by discrepant data on the solar composition. In order to solve this puzzle, we will build a new laboratory, LUNANOVA, and measure the rates of several neutrino-producing reactions in the sun. The new data will break the degeneracy between abundances and radiation transport, enable to use the sun as a calibrated particle source, and decisively improve the models of solar-like stars in general.
Yuan-Sen Ting , OSU The expansive, interdisciplinary nature of astronomy, combined with its open-access culture, makes it an ideal testing ground for exploring how Large Language Models (LLMs) can accelerate scientific discovery. Recent developments in LLM reasoning capabilities have shown substantial progress — our work demonstrates that AI agents can now achieve gold medal performance on International Olympiad on Astronomy and Astrophysics (IOAA) problems, indicating their growing analytical abilities. In this talk, I will present our recent advances in applying LLMs as agents to real-world astronomical challenges. We demonstrate how LLM agents can conduct end-to-end research tasks in galaxy spectral fitting — encompassing data analysis, strategy refinement, and knowledge accumulation — approaching capabilities similar to human intuition and domain knowledge, and extending to spectroscopic measurements that once took months of expert effort and to sifting hundreds of millions of light curves for rare systems. However, limitations remain. The Moravec paradox manifests clearly in astronomy: tasks requiring abstract reasoning may be easier for AI than seemingly simple perceptual tasks, and current models still struggle with chart reading, multi-modal data interpretation, and other fundamental astronomical workflows. To make large-scale applications viable, we developed lightweight, open-source specialized models (AstroSage) that match frontier models on astronomy Q&A at a fraction of the cost, evaluated against carefully curated astronomical benchmarks. Looking ahead, the path forward involves not just better models but a comprehensive ecosystem — rigorous benchmarks, literature-scale retrieval, and agent-ready tools. I will close by reflecting on what this transformation means for scientific understanding itself, and why understanding the universe remains a distinctly human project, even with non-human collaborators. To arrange a visit with the speaker during the visit, please contact their host: Hans-Walter Rix
Dr. Florian Meinert, 5th Institute of Physics, University of Stuttgart Circular Rydberg Atoms for Quantum Simulation Dr. Florian Meinert 5th Institute of Physics, University of Stuttgart Highly excited atoms named after Janne Rydberg have played an important role throughout the history of atomic physics. In recent years, their strong mutual interaction was key to realize quantum computers and simulators with individual atoms trapped in optical tweezer arrays. Coherence times or gate fidelities reached on these devices are, however, fundamentally limited by the lifetime of the Rydberg electron. Orders of magnitude longer lived Rydberg states can be created by spinning up the electron as much as quantum mechanics allows for. Such circular Rydberg states have already led to Nobel-prize winning works on fundamentals of atom-light interaction. In our experiments, we generate, coherently control, and trap individual Strontium circular Rydberg atoms in optical tweezer arrays. Along this endeavor, we have recently gained access to giant trapped circular Rydberg states with principal quantum numbers up to n=103 and measured record lifetimes of more than 10 milliseconds. This is achieved via Purcell suppression of blackbody radiation at room temperature. Exploiting the second valence electron available in Strontium further allowed us to couple the circular Rydberg electron to inner shell excitations, which can be used for local optical control. These results now pave the way for quantum information processing and sensing utilizing the combination of extreme lifetimes and giant Rydberg blockade.
