Theory HEP Seminar

The discovery potential of astrometric weak lensing

Cristina Mondino

PI

Compact structures of dark matter in our Galaxy can induce an apparent motion in background luminous sources through gravitational lensing. These effects can be searched for in precise astrometric surveys, such as Gaia. In this talk, I will focus on a class of observables designed to look for time-domain astrometric lensing effects induced by dark Galactic subhalos. I will present constraints on compact dark structures of ten million to a hundred million solar masses obtained from a search of local proper motion lensing distortions in the newest Gaia data. Future prospects for analyses that leverage on stellar angular acceleration measurements will also be discussed, together with the possibility of calibrating our techniques against known lenses.