We are very excited that Hidetoshi Omiya from Kyoto University will join us and present his work on the self-interacting axion condensate around spinning black holes. More information of the talk and the paper can be found below
Title: Impact of multiple modes on the evolution of self-interacting axion condensate around rotating black holes
Abstract:
Ultra-light particles, such as axions, form a macroscopic condensate around a highly spinning black hole by the superradiant instability. Due to its macroscopic nature, the condensate opens the possibility of detecting the axion through gravitational wave observations. However, the precise evolution of the condensate must be known for the actual detection. For future observation, we numerically study the influence of the self-interaction, especially interaction between different modes, on the evolution of the condensate in detail. First, we focus on the case when condensate starts with the smallest possible angular quantum number. For this case, we perform the non-linear calculation and show that the dissipation induced by the mode interaction is strong enough to saturate the superradiant instability, even if the secondary cloud starts with quantum fluctuations. Our result indicates that explosive phenomena such as bosenova do not occur in this case. We also show that the condensate settles to a quasistationary state mainly composed of two modes, one with the smallest angular quantum number for which the superradiant instability occurs and the other with the adjacent higher angular quantum number. We also study the case when the condensate starts with the dominance of the higher angular quantum number. We show that the dissipation process induced by the mode coupling does not occur for small gravitational coupling. Therefore, bosenova might occur in this case.
After Hidetoshi’s talk, William will introduce any of the following papers:
[1] Limits on Neutrino Emission from GRB 221009A from MeV to PeV using the IceCube Neutrino Observatory
[2] Hunting for Neutral Leptons with Ultra-High-Energy Cosmic Ray
[3] Observation of Seasonal Variations of the Flux of High-Energy Atmospheric Neutrinos with IceCube