2025/10/13 by --, Vladimir Toussaint · 1 citation
#FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc)
paper · doi:10.48550/arxiv.2510.11460
The Unruh effect--the prediction that an accelerated observer perceives the vacuum as a thermal bath--remains one of the most profound yet experimentally unverified consequences of quantum field theory. This work analyzes a model for the decay of an excited state within a uniformly accelerated cavity to address the historical null results and to identify an alternative, non-thermal signature. In our framework, a massless Dirac field confined to a cavity is coupled to an external massive Dirac field of mass M. Our analysis reveals that for fundamental fermions (such as the electron), the condition Mc2 ≫ ℏ a/c is satisfied at all achievable accelerations, placing the system in a regime of exponential suppression, Γacc/Γin ∼ exp(-2 M c2 / (ℏ a/c)) (with Γin the inertial decay rate). This suppression holds universally across all cavity sizes and experimental designs, providing a potential explanation within this model for the non-observation of Unruh effects. Furthermore, for intermediate-sized cavities (a l ∼ c2) with light external fields (Mc2 ≪ ℏ a/c), the model predicts a geometric enhancement of the decay rate, scaling as Γacc/Γin ∼ (a l/c2)/(ln(1 + a l/c2)), which arises from kinematic constraints rather than thermal stimulation. This enhancement, reaching up to 26% for realistic parameters (a∼ 1020 m/s2, l∼ 500~μm), is presented as a measurable signature accessible through quantum simulation platforms. Our results propose a unified framework that explains past experimental challenges and suggests a viable path forward for detecting non-inertial quantum effects.