Searches for Macroscopic Dark Matter: Lensing and Beyond

by Katz Andrey (CERN)

Tuesday 11 Dec 2018, 12:00 → 13:00 Europe/Madrid

IFAE Seminar room (IFAE)

Macroscopic Dark Matter (DM), in particular Primordial Black Holes (PBH)
and the Dark Matter miniclusters are well established dark matter
candidates. I will briefly motivate these scenarios and present the
current observational constraints on these ideas. I will further explain
why the constrains on macroscopic dark with masses below 10^22 gram are
so weak and discuss several ideas that can potentially improve the reach
is this region of parameter space. In particular, I will concentrate on
the femtolensing of the gamma ray bursts (GRBs) that has been put
forward as an exciting idea to probe the exotic astrophysical objects
with masses below 10^19 gram. I will critically review this idea,
properly taking into account the extended nature of of the source as
well as wave optics effects. These effects remove the previously claimed
femtolensing bounds on the primordial black holes, implying that vast
regions of the parameter space are not robustly constrained. I will
further entertain the possibility that a small fraction of GRBs with
short time variability can still be useful, however large number of such
bursts will be needed to be observed to achieve meaningful constraints.
I will present the sensitivity study of future observations. I will also
briefly discuss some other ideas that can be used to probe the
challenging regime of macroscopic DM with masses below 10^22 gram,
including the observations of White Dwarfs, neutron stars , picolensing
and lensing of the X-ray binaries.