Astrophysics Seminar

Recent results from the DESI survey provide compelling evidence for a dynamical dark energy component, challenging the long-standing cosmological constant paradigm. In this talk, I will present a mechanism based on an interacting quintessential scalar field dark energy and dark matter model mediated by a Yukawa-type coupling.

This fifth-force framework not only allows for a natural phantom crossing in the dark energy equation of state, as favored by DESI data, but also offers the first statistically evidence of dark sector interaction. I will discuss the theoretical foundation of this model and its observational signatures, emphasizing how it aligns with the latest DESI constraints. In the end, I will discuss about possible ways of looking for observational signatures of interacting dark sector in non-linear regime by studying how screening mechanisms affect halo structure and clustering through splashback radius in galaxy clusters.