Black Hole Shadow Asymmetry as a Probe of Quantum Hair: Predictions for Next-Generation Event Horizon Telescope

Here, we predict observable deviations from General Relativity in black hole shadows within Unified Quantum Gravity (UQG), where quantum hair $\Pi(r)$ modifies the near-horizon geometry. While the shadow size correction is subtle ($\approx 0.002\%$), we predict a measurable azimuthal asymmetry $\varepsilon \approx 0.3\%$ arising from the same quantum rigidity parameter $\xi \approx 0.0023$ that resolves the information paradox by accelerating the Page time. This establishes a monolithic connection: the mechanism that preserves thermodynamic unitarity (faster information release, $\tau_{\text{Page}}^{\text{UQG}} = 0.423$ vs $\tau_{\text{Page}}^{\text{GR}} = 0.500$) simultaneously generates observable geometric deviations in the photon sphere. We show that next-generation EHT (ngEHT, operational $\approx 2030$) with precision $\approx 0.1\%$ can test this prediction, providing a direct observational link between black hole thermodynamics and horizon geometry. For M87* and Sgr A*, we predict asymmetry amplitudes of $\Delta\theta \approx 0.13$ and $0.16 \mu\text{as}$ (microarcsegundos) respectively, testable at $\approx 3\sigma$ with ngEHT. This represents a falsifiable prediction that can distinguish UQG from GR under extreme gravitational conditions.