Binding in charged spherically symmetric objects

TL;DR

This paper investigates the gravitational binding of charged, spherically symmetric objects, extending previous results to anisotropic fluids, and concludes that objects with purely electromagnetic mass cannot be gravitationally bound.

Contribution

It generalizes earlier findings by including anisotropic fluids and analyzes the Oppenheimer-Volkov equation to understand binding contributions.

Findings

Pure electromagnetic mass objects cannot be gravitationally bound.

Localized mass contributes to gravitational binding in charged objects.

Anisotropic fluids do not alter the fundamental binding limitations.

Abstract

We consider the subject of self--binding in static, spherically symmetric objects consisting of a charged fluid. We have shown previously that in the case of a perfect fluid, only the localized part of the mass contributes to gravitational self--binding of such objects and that in the limiting case of objects comprised purely of electromagnetic mass, there is no gravitational binding. Here, we extend this result to the more general case of an anisotropic fluid. Our inspection of the Oppenheimer--Volkov equation allows tracking of both gravitational and non-gravitational contributions to binding of spherically symmetric objects and shows that those with pure electromagnetic mass cannot exist.