Speaker
Description
My work investigates the Casimir energy and its associated macroscopic mechanical torque between two microscopic parallel plates immersed in a spatially varying axionic background. Extending foundational models in axion electrodynamics, we evaluate the effective action of the photon and ghost sectors by calculating the eigenvalues of the inverse propagator and performing rigorous vacuum energy renormalization. We demonstrate that an axion gradient breaks the perfect rotational symmetry of the vacuum, causing zero-point fluctuations to exert a mechanical twist that attempts to align the parallel-plate cavity with the external field. In a perfectly purely spatial axion gradient $\vec{b}$, we show that the unperturbed isotropic vacuum yields no torque, and the leading-order physical effect emerges at $O(\vec{b}^2)$.
Furthermore, we generalize the framework to include a non-zero temporal axion gradient. Operating in the heavy temporal limit where the temporal gradient heavily dominates the spatial gradient ($b_4 \gg |\vec{b}|$) and the inverse cavity size ($b_4 \gg L_z^{-1}$), we derive a novel closed-form analytical expression for the resulting torque. These highlight macroscopic mechanical responses as a compelling phenomenological pathway for probing axion-like particles and mapping vacuum anisotropies.
| Primary Abstract Topic | Theory: Axions and Wave-Like-DM |
|---|