Speaker
Description
In the standard Fuzzy Dark Matter (FDM) scenario, the dark matter is composed of an ultra-light scalar field with coherence length and wave interference on astrophysical scales. However, scalar fields generically have quartic self-interactions that modify their dispersion relation and the associated evolution of density perturbations. I will begin by presenting the first dedicated analysis of the relationship between wave interference and the evolution due to self-interactions. For warm FDM, density perturbations are unable to grow on the expected self-interaction time scale because of interference effects, instead saturating on the much shorter de Broglie crossing time, with a dependence on the sign of the interaction. I will then introduce the Fuzzy Dark Sector (FDS) as a model extension with multiple interacting fuzzy degrees of freedom that interfere with each other. Remarkably, the FDS can recover a single cutoff scale in cosmology while generating a great diversity of halos at late times. Finally, I will discuss how these interference effects might be observed across a range of astrophysical environments and shed further light on interacting FDM.
