Many extensions of the Standard Model predict the presence of ultra-light bosons in the low energy theory. If any of these bosons are in the mass range of 10⁻²⁰ to 10⁻¹⁰ eV they will affect the evolution of astrophysical black holes through the superradiance process. When a boson's Compton wavelength is comparable to the size of a black hole, the boson binds to the black hole forming a gravitational atom in the sky. The occupation number of atomic states can grow exponentially to as large as 10⁷⁶, extracting energy and angular momentum from the black hole.
In this talk, I will present the first study of the electromagnetic signals coming from a black-hole superradiance cloud of a light dark photon. I will show how this dark photon superradiance cloud produces and hosts a rotating plasma of Standard Model charged particles. Crudely, this rotating plasma behaves like an electric dipole rotating around the black-hole spin direction. Just like a pulsar, which is qualitatively a rotating magnetic dipole, our system of a rotating electric dipole also produces extremely powerful, and potentially periodic, electromagnetic radiation. I will discuss the similarities and differences between our system and a pulsar, and several search strategies based on detailed numerical simulations.
Biography：黄俊午，2012年获得北京大学学士学位， 2017年获得斯坦福大学博士学位。随后在加拿大Perimeter Institute从事博士后研究，并于2020年9月起为Perimeter Institute助理教授(Faculty)。
Prof. Boqiang Ma