# Is Gravity Actually the Curvature of Spacetime?

## TL;DR

This paper proposes using a gravitational Casimir effect between superconductors to experimentally determine whether gravity is due to spacetime curvature, torsion, or non-metricity, challenging the traditional view of gravity as spacetime curvature.

## Contribution

It introduces a novel experimental approach using the gravitational Casimir effect to distinguish between different theories of gravity beyond General Relativity.

## Key findings

- Theoretical proposal for gravitational Casimir effect measurement
- Potential to differentiate gravity theories via boundary effects
- Implications for understanding the fundamental nature of gravity

## Abstract

The Einstein equations, apart from being the classical field equations of General Relativity, are also the classical field equations of two other theories of gravity. As the experimental tests of General Relativity are done using the Einstein equations, we do not really know, if gravity is the curvature of a torsionless spacetime, or torsion of a curvatureless spacetime, or if it occurs due to the non-metricity of a curvatureless and torsionless spacetime. However, as the classical actions of all these theories differ from each other by boundary terms, and the Casimir effect is a boundary effect, we propose that a novel gravitational Casimir effect between superconductors can be used to test which of these theories actually describe gravity.