APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Mateja Gonseca (University of Vienna)
Title: Multifield ultralight dark matter
Date (JST): Thu, Jul 25, 2024, 13:30 - 15:00
Place: Seminar Room A
Abstract: The ultralight dark matter (ULDM) model presents one of the most
compelling alternatives to cold dark matter due to the wave interference
effects which are potentially observable on cosmological scales. In the
simplest ULDM scenario, dark matter is described by a single scalar
field with a characteristic de Broglie wavelength scale which depends on
the mass of the corresponding dark matter particle. This is manifested
as dark matter halos having a central soliton, surrounded by order-one
granular fluctuations. In its simplest form and for the lightest
particle masses which display wave effects on the largest scales, this
model is by now tightly constrained by observations. However, extensions
involving more than one field or even self interactions have the
possibility to relax these constraints. Due to the non-linear nature of
the Schrödinger-Poisson system, this has to be explored with numerical
simulations. In my talk, I will present results from simulations
involving multiple fields or mixed scenarios. In particular, I will show
that dark matter halos composed of more fields are smoother which has
important implications for observable phenomena.