ABSTRACT:

I will discuss how black holes can become nature’s laboratories for new ultralight bosons and ongoing observations of gravitational waves can inform beyond the standard model theories. When a particle’s Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons. Theories beyond the Standard Model often include new, light, feebly interacting particles — including the QCD axion — whose discovery requires novel observations and search strategies. I will show how previously open parameter space of axions, as well as vector particles, can be constrained by observations of rapidly spinning black holes. I will also show how such black hole-boson systems may source up to thousands of monochromatic gravitational wave signals, and discuss my work to search for these signals in current data, enabling LIGO to discover or exclude new particles.