**76**: 106

https://doi.org/10.1140/epjc/s10052-016-3948-5

Regular Article - Theoretical Physics

## The minimum mass of a charged spherically symmetric object in *D* dimensions, its implications for fundamental particles, and holography

^{1}
High Energy Physics Theory Group, Department of Physics, Faculty of Science, Chulalongkorn University, Phyathai Rd., Bangkok, 10330, Thailand

^{2}
Theoretical Physics Group, Blackett Laboratory, Imperial College, London, SW7 2AZ, UK

^{3}
Department of Physics, Babes-Bolyai University, Kogalniceanu Street, 400084, Cluj-Napoca, Romania

^{4}
Department of Mathematics, University College London, Gower Street, London, WC1E 6BT, UK

^{5}
The Institute for Fundamental Study, “The Tah Poe Academia Institute”, Naresuan University, Phitsanulok, 65000, Thailand

^{6}
Thailand Center of Excellence in Physics, Ministry of Education, Bangkok, 10400, Thailand

^{*} e-mail: t.harko@ucl.ac.uk

Received:
24
December
2015

Accepted:
11
February
2016

Published online:
27
February
2016

We obtain bounds for the minimum and maximum mass/radius ratio of a stable, charged, spherically symmetric compact object in a *D*-dimensional space-time in the framework of general relativity, and in the presence of dark energy. The total energy, including the gravitational component, and the stability of objects with minimum mass/radius ratio is also investigated. The minimum energy condition leads to a representation of the mass and radius of the charged objects with minimum mass/radius ratio in terms of the charge and vacuum energy only. As applied to the electron in the four-dimensional case, this procedure allows one to re-obtain the classical electron radius from purely general relativistic considerations. By combining the lower mass bound, in four space-time dimensions, with minimum length uncertainty relations (MLUR) motivated by quantum gravity, we obtain an alternative bound for the maximum charge/mass ratio of a stable, gravitating, charged quantum mechanical object, expressed in terms of fundamental constants. Evaluating this limit numerically, we obtain again the correct order of magnitude value for the charge/mass ratio of the electron, as required by the stability conditions. This suggests that, if the electron were either less massive (with the same charge) or if its charge were any higher (for fixed mass), a combination of electrostatic and dark energy repulsion would destabilize the Compton radius. In other words, the electron would blow itself apart. Our results suggest the existence of a deep connection between gravity, the presence of the cosmological constant, and the stability of fundamental particles.

*© The Author(s), 2016*