DeCAF Seminar Series:

Abstract: Cosmological phase transitions are a frequent phenomenon in particle physics models beyond the Standard Model, and the corresponding gravitational wave signal offers a key probe of new physics in the early Universe. Depending on the underlying microphysics, the transition can exhibit either direct or inverse hydrodynamics, leading to a different phenomenology. Most studies to date have focused on direct transitions, where the cosmic fluid is pushed or dragged by the expanding vacuum bubbles. In contrast, inverse phase transitions are characterized by fluid profiles where the plasma is sucked in by the expanding bubbles. Using the sound shell model, we derive and compare the gravitational wave spectra from sound waves for direct and inverse phase transitions, providing new insights into the potential observable features and the possibility of discriminating among the various fluid solutions in gravitational wave experiments.

Speaker Bio: Eric completed his BSc and MSc degrees at RWTH Aachen University, including a one-year ERASMUS exchange at the IFT in 2014. He obtained his PhD in 2020 from the University of Mainz under the supervision of Pedro Schwaller, working on probes of new physics at colliders and in gravitational waves. He subsequently moved to a postdoctoral position at the Weizmann Institute of Science in the group of Gilad Perez, where he worked on quantum precision probes of ultralight dark matter. In 2024, he joined the IFT as a postdoctoral researcher, where he is currently working on cosmological phase transitions and gravitational wave signals in LISA. His research interests span the phenomenology of new physics and particle cosmology, in particular dark matter and stochastic gravitational wave backgrounds.