Thermal–Temporal Dynamics Investigating S2 Star Velocity Residuals and Irreversibility within the TSU Framework

This paper investigates the dynamical consequences of the Thermal Spacetime Unification (TSU) framework under non-equilibrium thermal conditions, with a focus on astrophysical and fundamental time-related phenomena. By analyzing the coupling between thermal gradients and temporal flow, the study proposes a mechanism capable of accounting for the observed velocity residuals of the S2 star (≈3–4 km/s) near the Galactic Center. In addition, the work examines the emergence of temporal irreversibility through a microscopic thermal–temporal constraint, suggesting that the arrow of time arises from dynamical consistency conditions rather than purely statistical arguments. As an independent observational test, the paper derives a perturbative TSU correction to Mercury’s orbital precession (~0.06 arcsec per century), providing a falsifiable prediction within current measurement capabilities. The manuscript is presented as an open-access theoretical research article and forms part of an ongoing research program on the thermodynamic foundations of spacetime.