Spinning black holes can transfer a significant fraction of their energy to ultralight bosonic fields via superradiance, condensing them in a corotating structure or “cloud.” This mechanism turns black holes into powerful particle detectors for bosons with extremely feeble interactions. To explore its full potential, the couplings between such particles and the Maxwell field in the presence of plasma need to be understood. In this work, we study these couplings using numerical relativity. We first focus on the coupled axion-Maxwell system evolving on a black hole background. By taking into account the axionic coupling concurrently with the growth of the cloud, we observe for the first time that a new stage emerges: that of a stationary state where a constant flux of electromagnetic waves is fed by superradiance, for which we find accurate analytical estimates. Moreover, we show that the existence of electromagnetic instabilities in the presence of plasma is entirely controlled by the axionic coupling; even for dense plasmas, an instability is triggered for high enough couplings.
Superradiance. Axionic couplings and plasma effects / Spieksma, Thomas F. M.; Cannizzaro, Enrico; Ikeda, Taishi; Cardoso, Vitor; Chen, Yifan. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 108:6(2023), pp. 1-32. [10.1103/PhysRevD.108.063013]
Superradiance. Axionic couplings and plasma effects
Enrico Cannizzaro
;Taishi Ikeda
;Vitor Cardoso
;
2023
Abstract
Spinning black holes can transfer a significant fraction of their energy to ultralight bosonic fields via superradiance, condensing them in a corotating structure or “cloud.” This mechanism turns black holes into powerful particle detectors for bosons with extremely feeble interactions. To explore its full potential, the couplings between such particles and the Maxwell field in the presence of plasma need to be understood. In this work, we study these couplings using numerical relativity. We first focus on the coupled axion-Maxwell system evolving on a black hole background. By taking into account the axionic coupling concurrently with the growth of the cloud, we observe for the first time that a new stage emerges: that of a stationary state where a constant flux of electromagnetic waves is fed by superradiance, for which we find accurate analytical estimates. Moreover, we show that the existence of electromagnetic instabilities in the presence of plasma is entirely controlled by the axionic coupling; even for dense plasmas, an instability is triggered for high enough couplings.File | Dimensione | Formato | |
---|---|---|---|
Spieksma_Superradiance_2023.pdf
solo gestori archivio
Note: Articolo su rivista
Tipologia:
Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza:
Tutti i diritti riservati (All rights reserved)
Dimensione
4 MB
Formato
Adobe PDF
|
4 MB | Adobe PDF | Contatta l'autore |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.