Wochenübersicht für die Woche vom

01 Jul 2024 bis 07 Jul 2024 (KW 27)

KW27 - KW28 - KW29 - KW30

02 Jul 2024

Physikalisches Kolloquium

Institut für Physik

16:15 Uhr s.t., HS KPH

Prof. Dr. Laura Kreidberg, Max Planck Institute for Astronomy, Heidelberg
The recent launch of the James Webb Space Telescope (JWST) has revolutionized the field of exoplanet atmosphere characterization, thanks to its unprecedented sensitivity and broad wavelength coverage. In this talk, I will give a tour of the latest JWST results for transiting exoplanets, from gas giants down to rocky worlds. For the largest planets, I'll focus on the complex physical processes recently revealed in their atmospheres, including photochemistry, 3D effects, and cloud formation. Pushing down to smaller worlds, I'll share the first measurements of chemical composition for the elusive sub-Neptune population; and finally give an update on which (if any) rocky planets have atmospheres at all.
Slides here...

Theorie-Palaver

Institut für Physik

14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor)

Jorinde van de Vis, Leiden U.
In many extensions of the Standard Model, the universe underwent one or several first order phase transitions. Such phase transitions proceed via the formation and collision of bubbles. The bubble collisions can source a stochastic gravitational wave background signal. In the case of the electroweak phase transition, the characteristic frequency would fall right in the sensitivity band of LISA. We can thus use data from gravitational wave experiments to probe physics beyond the standard model. In this talk, I will discuss the contribution to the gravitational wave signal from sound waves, which is often the dominant contribution. Predictions of the gravitational wave spectrum typically rely on hydrodynamic lattice simulations of the scalar-plasma system. Hydrodynamic solutions of a single expanding bubble provide a bridge between the particle physics model and the hydrodynamic lattice simulation and encode much of the underlying particle physics information. Two relevant quantities in this computation are the bubble expansion velocity and the kinetic energy budget. I will discuss the computation of both quantities and present two approximation schemes for computing the wall velocity: the scenario of local thermal equilibrium and of a large enthalpy jump between the two phases.

03 Jul 2024

PRISMA+ Colloquium

Institut für Physik

13:00 Uhr s.t., Lorentz-Raum, 05-127, Staudingerweg 7

PD Dr. Teresa Marrodan, MPI Heidelberg
The nature of dark matter is one of the most important open questions in modern physics. Astronomical and cosmological measurements provide strong evidence for its existence. Despite the many hypothetical candidate particles that have been proposed, experimental efforts have so far yielded only null results. Direct detection is a promising method for determining the nature of this dark component of the Universe. It allows, for example, to probe the existence of WIMPs (Weakly Interacting Massive Particles) via their elastic scattering off target nuclei down to tiny interaction cross sections. Several experimental strategies have been developed to measure the small recoil induced by dark matter interactions, with liquid xenon TPCs being one of the most successful. This talk will discuss the status and main results of XENONnT and outline future plans with the DARWIN/XLZD observatory.
Slides here...