Emergence of Time from Quantum Decoherence in Curved Spacetime

We develop a theoretical framework that links relativistic acceleration, quantum decoherence, and entropy production to define an emergent concept of time. A formula for the decoherence rate of a two-level quantum system under constant acceleration is proposed, derived from the Unruh effect and thermal detailed balance. From this rate, we derive a cumulative phase shift associated with the loss of coherence, which we interpret as an intrinsic marker of thermodynamic time. This approach suggests that time arises as a consequence of irreversible quantum processes in curved spacetime.