Stability of Black Hole Solutions in Unified Quantum Gravity: The Role of Thermodynamic Dissipation

Here, we investigate the stability of black hole solutions in Unified Quantum Gravity (UQG) under linear perturbations. Without dissipation, we find marginal stability with purely real eigenfrequencies ($\text{Im}(\omega) = 0$), indicating critical damping. Including physical dissipation mechanisms—Hawking radiation, horizon absorption, quantum decoherence, and crucially, thermodynamic dissipation from the fundamental UQG relation $H \propto dS/dt$—we achieve full stability with $\text{Im}(\omega) < 0$ for all modes. The thermodynamic dissipation mechanism is dominant, with damping timescales $\tau \sim 300\text{-}600\,M$, and provides a natural, universal stabilization unique to UQG. This mechanism emerges directly from entropy production driving cosmic expansion, establishing a deep connection between black hole dynamics and thermodynamics. Our results demonstrate that UQG solutions are physically viable and make testable predictions for gravitational wave ringdown observations with LIGO, Virgo, and future detectors.