28 Nov 2022
RIND seminar on Mathematical Physics and String Theory
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna 16 Uhr c.t., None 
Enno Keßler, MPIM Bonn  
Jholomorphic curves or pseudoholomorphic curves are maps from Riemann
surfaces to symplectic manifolds satisfying the CauchyRiemann equations.
Jholomorphic curves are of great interest because they allow to construct
invariants of symplectic manifolds and those invariants are deeply related to
topological superstring theory. A crucial step towards Gromov–Witten
invariants is the compactification of the moduli space of Jholomorphic curves
via stable maps which was first proposed by Kontsevich and Manin.
In this talk, I want to report on a supergeometric generalization of J
holomorphic curves and stable maps where the domain is a super Riemann
surface. Super Riemann surfaces have first appeared as generalizations of
Riemann surfaces with anticommutative variables in superstring theory. Super
Jholomorphic curves couple the equations of classical Jholomorphic curves
with a Dirac equation for spinors and are critical points of the
superconformal action. The compactification of the moduli space of super J
holomorphic curves via super stable maps might, in the future, lead to a
supergeometric generalization of GromovWitten invariants.
Based on arXiv:2010.15634 [math.DG] and arXiv:1911.05607 [math.DG], joint with
Artan Sheshmani and ShingTung Yau.  
at Zoom  

aktuell
29 Nov 2022
TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Markus Fröb, U. Leipzig  
Perturbative Quantum Gravity (pQG), the effective quantum field theory of gravitational fluctuations around a given background, is currently the only experimentally accessible theory of quantum gravity. Its treelevel predictions, in the form of temperature fluctuations of the Cosmic Microwave Background, have been experimentally confirmed, and it is possible that loop corrections are accessible to future experiments. However, while the treelevel results are well understood also from a theoretical point of view, the diffeomorphism symmetry of gravity makes the construction of invariant observables very difficult beyond this. Only recently, this issue has been overcome, and a class of causal invariant observables has been constructed. I will discuss this construction and how it can be related to observations, and present some predictions of pQG for graviton loop corrections to the Newtonian gravitational potential and the Hubble rate, the local expansion rate of the universe. Lastly, I show that pQG also predicts that spacetime becomes noncommutative at the Planck scale, but in a different way from previous approaches. The talk is based (in particular) on the recent papers arXiv:1806.11124, 2108.11960, 2109.09753 and 2207.03345.  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Katrin AmannWinkel, MPI für Polymerforschung Mainz  
Water is ubiquitous and the most important liquid for life on earth. Although the water molecule is seemingly simple, various macroscopic properties of water are most anomalous, such as the density maximum at 4°C or the divergence of the heat capacity upon cooling. Computersimulations suggest that the anomalous behaviour of ambient and supercooled water could be explained by a two state model of water. An important role in this ongoing debate plays the amorphous forms of water. Since the discovery of two distinct amorphous states of ice with different density (high and low density amorphous ice, HDA and LDA) it has been discussed whether and how this phenomenon of polyamorphism at high pressures is connected to the occurrence of two distinct liquid phases (HDL and LDL). Xray free electron laser allow us to investigate metastable states of supercooled water within nano to microseconds. In my talk I will give an overview on our recent Xray experiments on supercooled water and amorphous ices.  

zukünftige Termine
30 Nov 2022
PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Tetyana Galatyuk, GSI Darmstadt  
What happens when gold nuclei, accelerated to about 90% of the speed of light, strike gold nuclei at rest? For an extremely short time, t~10^23 seconds, states of matter at extreme temperatures (10^12 K) and densities (>280 Mt/cm^3) are produced. The microscopic properties of the stronginteraction matter under extreme conditions of temperature and density is a topic of great current interest. Despite 18 orders of magnitude difference in system size and time, the conditions present in heavyion collisions share great overlap with the conditions of the stronginteraction matter in neutronstar mergers. The possibility to form and explore in the laboratory stronginteraction matter under extreme conditions is truly fascinating.
The Compressed Baryonic Matter (CBM) experiment at FAIR has the potential to discover the most prominent landmarks of the QCD phase diagram expected to exist at high net baryon densities. The measurement of comprehensive set of diagnostic probes offers the possibility to find signatures of exotic phases, and to discover the conjectured first order deconfinement phase transition and its critical endpoint.
In this talk the referent will focus on relevant observables to study criticality, emissivity, vorticity and equationofstate of baryon rich matter. Particular emphasis is put on rare probes which are not accessible by other experiments in this energy range.  

SPICESpin+X Seminar
TUK and JGU 15:00 Uhr s.t., Zoom 
Alice Mizrahi, CNRSThales  
Multilayer spintronic neural networks with radiofrequency connections  
at Zoom and SPICE YouTube Channel  

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDynSeminar)
JGU 10:00 Uhr s.t., TUK, Building 76, Room 276 (LASE) 
Prof. Victor L’vov, Dept. of Chemical and Biological Physics, Weizmann Institute of Science  
Hydrodynamic turbulence in superfluid Helium: basic ideas, experiments, and physical models  
at Zoom  

01 Dec 2022
Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDynSeminar)
JGU 16:15 Uhr s.t., 01122 Newton Raum 
Martin Beye, DESY  
Resonant inleastic Xray scattering (RIXS) especially in the soft Xray region has seen a tremendous increase in applicability and scientific insight over the recent years. This was largely enabled by progress in instrumentation and theoretical description. Now the time is ripe to apply RIXS to pressing problems and develop the technique further making full use of the capabilities of novel Xray sources. In my talk, I will address three main themes from my research:
1. Timeresolved RIXS at freeelectron lasers applied to relevant dynamic processes in chemistry (on surfaces, in liquids and in solid catalysts)
2. RIXS with micrometer spatial resolution to resolve domain dynamics in complex materials and on devices inoperando
3. Nonlinear spectroscopies in the soft Xray range to enhance information content and signal levels I will show and discuss experimental results from all research themes and point to future development directions.  
