On the Equivalence Principle and a Unified Description of Gravitation and Electromagnetism

TL;DR

This paper explores a unified framework for gravity and electromagnetism based on an extended equivalence principle, proposing that different charge-to-mass ratios lead to distinct spacetime metrics, and discusses experimental implications.

Contribution

It introduces a novel equivalence principle for electromagnetism and develops a unified spacetime description of gravitation and electromagnetic fields.

Findings

Electric field outside a charged sphere acts independently of gravity.

The metric outside a charged sphere depends on the charge-to-mass ratio of test particles.

Existing experiments can be explained by the proposed electromagnetic equivalence principle.

Abstract

We first investigate the form the General Relativity Theory would have taken had the gravitational mass and the inertial mass of material objects been different. We then extend this analysis to electromagnetism and postulate an equivalence principle for the electromagnetic field. We argue that to each particle with a different electric charge-to-mass ratio in superimposed gravitational and electromagnetic fields there corresponds a spacetime manifold whose metric tensor $g_{\mu\nu}$ describes the dynamical actions of gravitation and electromagnetism. The electric field outside a charged sphere asserts itself independently rather than contributing to the gravitational field. The contribution of the electric field to the spacetime metric outside the charged sphere is shown to be similar to the gravitational one in the Schwartzschild metric but with a charge-to-mass ratio dependence of the test particle instead of the Reissner - Nordstr\"om metric, resulting in a unified description of gravitation and electromagnetism. We point out that there are existing experiments whose results can be explained by the equivalence principle for the electromagnetic field presented here. Additional experimental predictions of the theory are mentioned.