Program summer term 2023
Monday, July 03, 2023, 4:30pm Physics lecture hall
Prof. Dr. Mario Berta (RWTH Aachen University)
Host: Hendrik Bluhm
Monday, June 26, 2023, 4:30pm Physics lecture hall
Prof. Marc Schumann (Universität Freiburg)
Exploring the Dark Universe
Ample of indirect evidence indicates that the vast majority of the matter in the Universe is dark and neither emits nor absorbs light. The existence of this dark matter is one of the strongest hints that our current understanding of the fundamental constituents of the Universe is incomplete, as no known particle has the right properties. We will discuss the evidence for dark matter and the experimental approaches to directly detect the dark matter particles in our galactic neighborhood. These searches are currently led by large low-background detectors using cryogenic liquid xenon as dark matter target. As these instruments get larger and achieve better and better background levels, the sensitivity to dark matter particles increases and additional science channels become accessible.
Host: Christopher Wiebusch
Monday, June 05, 2023, 4:30pm Physics lecture hall
Dr. David Dahmen ( Jülich Research Centre)
Disordered-systems and field-theoretic approach to heterogeneous neural networks
Neural networks in the brain and in machine learning are disordered systems of many interacting nonlinear units. In biological networks one predominant form of disorder is the sparse and heterogeneous local connectivity between neurons; in artificial networks it is the random initialization of couplings before training on a specific task. While the amount of randomness in both systems has been linked to critical behavior and computational performance, a full understanding of the dynamical and functional consequences is currently still lacking. In this talk, I demonstrate how to use field-theoretic tools from statistical physics of spin glasses to obtain predictions for spatio-temporal correlation patterns, the hallmarks of collective behavior and function in biological and artificial neural networks, and compare these predictions to electrophysiological recordings of parallel neural activity in the brain.
Host: Michael Kraemer
Monday, May 22, 2023, 4:30pm Physics lecture hall
Prof. Dr. Hans-Walter Rix (MPI for Astronomy Heidelberg)
Where do black holes in the Universe come from?
Over the last 50 years the existence of black holes has been established by different
astrophysical means: the dynamics of stars and gas, emission from accretion disks
surrounding them and gravitational waves. Black holes appear to exist over a vast range
masses, from a few times the mass of the Sun to a few billion Solar masses. But in many
circumstances black holes have remained undetectable by current detection efforts, and
we may just see the tip of the population iceberg. I’ll discuss some of the ongoing and
upcoming efforts (including our own) to detect new parts of the black hole population. And
I’ll sketch what this implies for their origin: When do massive stars leave black holes behind?
Do all black holes in the Universe ultimately trace back to stellar remnants?
And, can black holes be a significant part of dark matter?
Host: Oliver Pooth
Monday, May 8, 2023, 4:30pm Physics lecture hall
Dr. Axel Lindner (DESY)
Axion searches at DESY: starting now!
The worldwide interest in axions and other weakly interacting slim particles (WISPs) as constituents of a dark sector of nature has strongly increased over the last years. A vibrant community is developing, constructing and operating corresponding experiments, so that promising parameter regions will be probed within the next 15 years.
Many of these approaches rely on WISPs converting to photons. At DESY in Hamburg, larger-scale projects are pursued: the “light-shining-through-a-wall” experiment, ALPS II in the HERA tunnel, is about to start data taking. The solar helioscope BabyIAXO is nearly ready to start construction, while the dark matter haloscope MADMAX is in the prototyping phase.
This presentation will introduce the physics cases and focus on the axion search activities ongoing at DESY in Hamburg.
Host: Lutz Feld
Friday 28th April 2023, 4pm Physics lecture hall
Symposium on the occasion of the 80th birthday of Prof. Gernot Güntherodt
16:05 – 16:15 Opening
16:15 – 16:30 Ulrich Rüdiger (Rector of the RWTH Aachen University)
16:30 – 16:50 Stuart Parkin (Max Planck Institute of Microstructure Physics, Halle (Saale))
Memory on the racetrack
16:50 – 17:10 Werner Hanke (University of Würzburg)
Room-temperature excitons in a topological insulator
17:30 – 17:50 Burkard Hillebrands (TU Kaiserslautern)
Spin waves and magnonics
17:50 – 18:10 Ioana Slabu (Institute of Applied Medical Engineering, RWTH Aachen Univ.)
Precision Medicine with Magnetic Nanomaterials
18:10 – 18:30 Dieter Vollhardt (University of Augsburg)
Theories in the Natural Sciences
18:30 – 18:40 Conclusion
The symposium will take place in the Physics lecture hall (28D 001).