Pith. sign in

Probing Axions via Spectroscopic Measurements of S-stars at the Galactic Center

6 Pith papers cite this work. Polarity classification is still indexing.

6 Pith papers citing it
abstract

Axions, encompassing both QCD axions and axion-like particles, can generate loop-induced quadratic couplings to electromagnetic field strength tensors, resulting in oscillatory shifts of the fine-structure constant. Near a Kerr black hole, an axion field with a Compton wavelength comparable to the event horizon can exponentially grow through the superradiance mechanism, potentially reaching a maximum amplitude near the decay constant, provided this scale is below approximately $10^{16}$ GeV. The saturated axion cloud formed around the black hole induces characteristic oscillations in the fine-structure constant, with a period of $10$-$40$ minutes determined by the axion mass, and a spatial profile governed by the axion wavefunction and its coupling strength. At lower axion masses, axion dark matter can form a soliton-like core characterized by a nearly constant amplitude, extending measurable variations of the fine-structure constant to greater distances. Precise spectroscopic measurements of S-stars orbiting the supermassive black hole Sgr A$^*$ provide a powerful probe of these predictions, potentially excluding substantial regions of parameter space for quadratic scalar couplings to photons, owing to the high boson density near the Galactic Center.

citation-role summary

background 2

citation-polarity summary

years

2026 3 2025 3

roles

background 2

polarities

background 2

representative citing papers

Stellar Superradiance and Low-Energy Absorption in Dense Nuclear Media

hep-ph · 2025-12-15 · unverdicted · novelty 6.0

Collective nucleon scattering in neutron-star matter suppresses the effective absorption of ultralight bosons at the long wavelengths relevant for superradiance, weakening the link between stellar cooling bounds and superradiant instability rates.

citing papers explorer

Showing 6 of 6 citing papers.