A Smoking-Gun Signature for Ultralight Scalar Dark Matter: 21-cm Oscillation Prediction for the Square Kilometre Array (SKA)

This preprint presents a robust, parameter-free prediction of the Unary Field Theory (UFT): a specific oscillation in the 21-cm brightness temperature power spectrum at a comoving wavenumber of kJ(z=10)=1.34Mpc−1. The oscillation originates from the same physical mechanism—quantum pressure suppression at the Jeans scale—that produces the weak lensing oscillation at ℓ0=3608(at z=1). The prediction adheres to the kJ∝a1/4scaling law and is fully testable with the upcoming Square Kilometre Array (SKA-Low). Key Parameters: Scalar Field Mass (mϕ): 1.1×10−22eV Jeans Scale (z=10): kJ=1.34Mpc−1 Oscillation Amplitude (B): 0.049 Cosmological Model: ΛCDM with specific parameters (Ωϕ=0.2693, H0=70.2km/s/Mpc) This work outlines the observational strategy for detecting this signal using SKA-Low, highlighting its discriminatory power against ΛCDM and astrophysical foregrounds. A joint detection with weak lensing would provide an irrefutable confirmation of ultralight scalar dark matter. Related Publication DOI: [在此处填入主论文的DOI,例如 10.5281/zenodo.21186809]