Searching for New Particles with Black Hole Superradiance
Ultralight bosons can induce superradiant instabilities in spinning black holes, tapping their rotational energy to trigger the growth of a bosonic condensate.
Traditionally, searches for continuous gravitational waves have looked for neutron stars with varying mass or current quadrupoles. If information is known about the source — such as a sky position or even a full ephemeris — this information can be used to run a more sensitive search around the known parameters of that source. These directed and targeted searches have set new and ever-improving constraints on the properties of individual neutron stars.
The Continuous Waves (CW) Search Group of the LIGO Scientific Collaboration and Virgo Collaboration carries out a diverse suite of searches for a diverse set of possible CW sources. Assumptions underlying these searches will be discussed, along with strategies used so far to keep our eyes wide open while also giving due attention to the most promising sources. One important assumption to date has been that fast-spinning, non-axisymmetric neutron stars are the most promising class of CW sources.