Repulsive Casimir force in stationary axisymmetric spacetimes

TL;DR

This paper investigates how stationary axisymmetric spacetimes affect Casimir energy, revealing conditions under which the force can become repulsive, with applications to Kerr and linear motion scenarios.

Contribution

It demonstrates that Casimir energy can change sign and become repulsive depending on apparatus orientation in such spacetimes, a novel insight in the field.

Findings

Casimir energy can be repulsive in certain orientations.

The sign change depends on apparatus orientation relative to dragging direction.

Applications include Kerr geometry and linear motion scenarios.

Abstract

We study the influence of stationary axisymmetric spacetimes on Casimir energy. We consider a massive scalar field and analyze its dependence on the apparatus orientation with respect to the dragging direction associated with such spaces. We show that, for an apparatus orientation not considered before in the literature, the Casimir energy can change its sign, producing a repulsive force. As applications, we analyze two specific metrics: one associated with a linear motion of a cylinder and a circular equatorial motion around a gravitational source described by Kerr geometry.