Rapidly rotating black holes are known to develop instabilities in the presence of a sufficiently light boson, a process which becomes efficient when the boson's Compton wavelength is roughly the size of the black hole. This phenomenon, known as black hole superradiance, generates an exponentially growing boson cloud at the expense of the rotational energy of the black hole. For astrophysical black holes with $M \sim \mathcal{O}(10) \, M_\odot$, the superradiant condition is achieved for bosons with $m_b \sim \mathcal{O}(10^{-11} ) \, {\rm eV}$; intriguingly, photons traversing the intergalactic medium (IGM) acquire an effective mass (due to their interactions with the ambient plasma) which naturally resides in this range. The implications of photon superradiance, i.e. the evolution of the superradiant photon cloud and ambient plasma in the presence of scattering and particle production processes, have yet to be thoroughly investigated. Here, we enumerate and discuss a number of different processes capable of quenching the growth of the photon cloud, including particle interactions with the ambient electrons and back-reactions on the effective mass (arising e.g. from thermal effects, pair-production, ionization of of the local background, and modifications to the dispersion relation from strong electric fields). This work naturally serves as a guide in understanding how interactions may allow light exotic bosons to evade superradiant constraints.
Enlightening dark moments of neutrino with superradiance
Institute of Mathematical Sciences, HBNI（数学科学研究所，HBNI）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Indian Institute of Science Education and Research Berhampur（贝赫拉普尔印度科学教育研究学院）
Vacuum-Triggered Instability in Paired Superradiance
State Key Laboratory of Ultraintense Laser Science and Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences（中国科学院上海光学精密机械研究所）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；State Key Laboratory of Dark Matter Physics, Shanghai Jiao Tong University（上海交通大学）；Shanghai Normal University（上海师范大学）；ShanghaiTech University（上海科技大学）
Stellar Superradiance and Low-Energy Absorption in Dense Nuclear Media
Weizmann Institute of Science（魏茨曼科学研究所）；Niels Bohr Institute（尼尔斯·玻尔研究所）；CENTRA, Departamento de Física, Instituto Superior Técnico (IST), Universidade de Lisboa (UL)（里斯本大学高级技术学院物理系中心引力研究中心）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）；Shanghai Jiao Tong University（上海交通大学）；University of Manchester（曼彻斯特大学）；The Hong Kong University of Science and Technology（香港科技大学）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）
