Dark compact objects can arise naturally in a variety of dark sectors. Clouds of dark matter between a source star and an observer could effectively act as a "lampshade" and dim starlight if the dark sector couples to the Standard Model photon. These dimming effects can be searched for in microlensing surveys, which measure the brightness of stars as a function of time. By considering the...
Primordial black hole (PBH) dark matter (DM) can be probed by "picolensing". Widely spatially separated gamma-ray detectors near Earth would observe parallax of an intervening PBH lens with respect to a cosmologically distant gamma-ray burst (GRB). This parallax can be of order the Einstein angle of the lens, resulting in differential magnification of the source as viewed from the two...
