Determine the physical origin of HFQPOs and identify the correct QPO model

Determine the physical origin of high-frequency quasi-periodic oscillations and establish which of the eleven considered kinematic and resonance models provides the correct description for each black-hole source.

Background

The paper compares nine resonance models with two kinematic models because the observed HFQPOs can be represented by several competing combinations of orbital and epicyclic frequencies. Statistical fits and spin comparisons do not uniquely identify one mechanism, and the available data generally cannot distinguish Kerr from hairy Kerr geometries.

Consequently, the physical mechanism producing HFQPOs and the correct model for each source remain unresolved. Resolving this issue is important because inferred black-hole hair and spin constraints depend strongly on how the observed frequencies are identified.

References

Since the physical origin of the HFQPOs is not yet conclusively established, it is not possible to identify apriori which model provides the most appropriate description for a given source.

— Probing hairy Kerr black holes through quasi-periodic oscillations II: a study based on the resonance models  (2610.11378 - Dasgupta et al., 8 Oct 2026) in Section 6, paragraph beginning “We now compare the performance” and Section 7, first paragraphs