Résumé |
I will argue that many theories in which the dark matter is a light boson (with a mass < eV) lead to theoretically and observationally interesting dark matter small-scale structure. As a particular, directly calculable, example I will show that this is the case for any new vector boson with non-zero mass (a âdark photonâ or âProca bosonâ) that is present during inflation, at which time a relic abundance is automatically produced purely from vacuum fluctuations. Due to a remarkable parametric coincidence between the size of the primordial density perturbations and the scale at which quantum pressure is relevant, a substantial fraction of the dark matter inevitably collapses into gravitationally bound solitons. The central densities of these âdark photon starâ, or âProca starâ, solitons are typically a factor 10^6 larger than the local background dark matter density today. I will also mention some possible observational consequences and directions for future work. |