Bound of Casimir Effect by Holography

TL;DR

This paper proposes that holography sets a universal lower bound on the Casimir effect, verified across various models including free theories, critical models, and non-conformal quantum field theories.

Contribution

It introduces a holographic lower bound on the Casimir effect and demonstrates its validity across multiple models and dimensions, extending beyond conformal theories.

Findings

Holography imposes a universal lower bound on the Casimir effect.

The bound is verified in free theories, Ising, and O(N) models at criticality.

The bound applies to non-conformal quantum field theories as well.

Abstract

Inspired by the Kovtun-Son-Starinet bound, we propose that holography imposes a lower bound on the Casimir effect. For simplicity, we focus on the Casimir effect between parallel planes for three-dimensional conformal field theories and briefly comment on the generalizations to other boundary shapes and higher dimensions. Remarkably, the ghost-free holographic models impose a universal lower bound on the Casimir effect. We verify the holographic bound by free theories, the Ising model, and $O(N)$ models with $N=2,3$ at critical points and prove it for the two-dimensional case. Remarkably, a general class of quantum field theories without conformal symmetries also obeys the holographic bound.