Hunting for ultralight fields with galactic dynamics
by Dr. Kfir Blum
at Particles and Fields Seminar
Mon, 09 Nov 2020, 14:00
Ultralight dark matter (ULDM) would form cores at the centres of galaxies, allowing to detect (or constrain) the lowest allowed mass for dark matter using gravity alone. Numerical simulations of ULDM galactic halos found empirical scaling relations between the mass of the host galaxy and the mass of the core. We show that this empirical result amounts to an equality between the specific kinetic energy in the core and in the host halo. Contrasting this prediction to the measured rotation curves of low surface-brightness galaxies, we show that ULDM in the mass range m < 10^-21eV, which has been invoked as a possible solution of small-scale puzzles of LCDM, is in tension with the data. We discuss additional phenomena including gravitational lensing, stellar dynamics near supermassive black holes, and runaway stars in dwarf galaxies, that probe ULDM from m ~ 10^-25eV up to m ~ 10^-18eV even if it makes up only a fraction of the total DM density.
Created on 04-11-2020 by Palti, Eran (palti)
Updaded on 04-11-2020 by Palti, Eran (palti)