[Lecture] Black-hole superradiance: probing the dark universe with compact objects and gravitational waves
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Online (zoom)
KIAS
Title: Black-hole superradiance: probing the dark universe with compact objects and gravitational waves
Speaker: Prof. Paolo Pani (Universita` di Roma & Sezione INFN Roma1)
Abstract:
Ultralight bosonic fields (e.g. stringy axions, axion-like particles, dark photons, light spin-2 fields) are compelling dark-matter candidates and provide an interesting alternative to the WIMP paradigm. These fields have eluded particle detectors so far, but can dramatically affect the strong-gravity dynamics of compact objects (black holes and compact stars) in various detectable ways. Light bosonic fields can trigger superradiant instabilities which have peculiar signatures, e.g. they produce ``gaps'' in the mass-spin diagram of astrophysical black holes and predict a measurable spin-down rate of pulsars. These effects can be used to constrain axion-like particles, dark photons, and massive gravitons. Because of their tiny mass and coupling to the Standard Model, detecting axions and other light bosons in the lab is extremely challenging. However, boson condensates formed through superradiance would emit a periodic gravitational-wave signal (whose frequency is related to the boson mass) which can be detected with present and future gravitational-wave interferometers, either as stochastic background or as continuous resolvable sources. I will review recent results and almost-model-independent smoking guns for physics beyond the Standard Model in this scenario.
