Driving the Unruh Response

Abstract: The Unruh effect, central to quantum field theory in curved spacetime, states that uniformly accelerated observers perceive the Minkowski vacuum as a thermal ensemble of Rindler excitations. Building on this foundation and drawing analogies from squeezing in quantum optics, we investigate how entangled, non-thermal excitations generated by bilocal driving sources contribute to the accelerated response. These paired excitations act as inertial microstates within the thermal Unruh ensemble, suggesting that portions of the effect can be interpreted as source-driven. To capture this, we employ modular automorphisms from algebraic QFT to track localization of modes and observers across nested Rindler wedges. We then construct compact wave-packet approximations using parabolic cylinder functions, providing a smooth interpolation between wedge-supported thermal modes and fully localized non-thermal excitations. This approach situates the Unruh response within a broader framework where standard thermality emerges alongside, and sometimes from, localized source-induced structure.