Black hole superradiance is a powerful tool in the search for ultra-light bosons. Constraints on the existence of such particles have been derived from the observation of highly spinning black holes, absence of continuous gravitational-wave signals, and of the associated stochastic background. However, these constraints are only strictly speaking valid in the limit where the boson's interactions can be neglected. In this work we investigate the extent to which the superradiant growth of an ultra-light dark photon can be quenched via scattering processes with ambient electrons. For dark photon masses $m_{γ^\prime} \gtrsim 10^{-17}\,{\rm eV}$, and for reasonable values of the ambient electron number density, we find superradiance can be quenched prior to extracting a significant fraction of the black-hole spin. For sufficiently large $m_{γ^\prime}$ and small electron number densities, the in-medium suppression of the kinetic mixing can be efficiently removed, and quenching occurs for mixings $χ_0 \gtrsim \mathcal{O}(10^{-8})$; at low masses, however, in-medium effects strongly inhibit otherwise efficient scattering processes from dissipating energy. Intriguingly, this quenching leads to a time- and energy-oscillating electromagnetic signature, with luminosities potentially extending up to $\sim 10^{57}\,{\rm erg / s}$, suggesting that such events should be detectable with existing telescopes. As a byproduct we also show that superradiance cannot be used to constrain a small mass for the Standard Model photon.
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）
Signatures of High-Frequency Gravitational Waves in Electromagnetic Cavities
Institute for Astroparticle Physics, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院天体粒子物理研究所）；Physikalisches Institut, Rheinische Friedrich-Wilhelms-Universität Bonn（波恩大学物理研究所）
Simulating Binary Neutron Stars with Hybrid Equation of States: Gravitational Waves, Electromagnetic Signatures, and Challenges for Numerical Relativity
Neutrino and electromagnetic signatures from Superluminous Supernovae: a case study for SN 2017egm
Fermi National Accelerator Laboratory（费米国家加速器实验室）；University of Chicago（芝加哥大学）；Tohoku University（东北大学）；University of Tartu（塔尔图大学）；Columbia University（哥伦比亚大学）；Flatiron Institute（平顿研究所）
Electromagnetic probes as signatures for a first-order QCD phase transition
University of Malaya（马来亚大学）；GSI Helmholtzzentrum für Schwerionenforschung GmbH（GSI亥姆霍兹重离子研究中心有限公司）；Frankfurt Institute for Advanced Studies（法兰克福高级研究所）；Johann Wolfgang Goethe-Universität（约翰·沃尔夫冈·歌德大学）；Helmholtz Research Academy Hessen for FAIR (HFHF)（黑森亥姆霍兹FAIR研究院）；Suranaree University of Technology（素拉那瑞理工大学）
