Speaker
Florian Niedermann
Description
I will discuss how emerging observational tensions can be interpreted as signs of new dark-sector microphysics. In particular, I will present a model in which a symmetry-breaking phase transition reheats the dark sector after Big Bang nucleosynthesis, with dark matter coupled to dark radiation through a gauge force. This interaction generates dark acoustic oscillations on scales close to the baryon acoustic scale, leaving a distinctive and testable imprint in the matter power spectrum. The same physics also offers an early-Universe alternative to evolving dark energy as a way of addressing recent anomalies in late-time cosmological data.