Casimir effect around an Ellis wormhole

Abstract

We discuss the Casimir effect in a small cavity, moving in a circular orbit around an Ellis wormhole. We show that the interplay between the spacetime geometry and the cavity orbital motion gives rise to a distortion in the Casimir energy density, causing a reduction of its absolute value. Quite interestingly, such effect can be observed also when the cavity moves on a circular geodesic (albeit unstable) orbit at the wormhole throat, where a comoving observer becomes locally inertial (namely, the observer’s reference frame reduces to a geodesic, Fermi-Walker transported one). In that respect, the discussed effect appears as a nonlocal quantum effect by means of which some properties of the underlying spacetime geometry, hidden to local classical measurements, can be captured and unveiled.