http://arxiv.org/pdf/1301.3923v1.pdf
A sum rule for charged elementary particles This paper draws a connection between charge and the behavior of the vacuum in a region. Charge and dipoles shapes the vacuum and also the speed that light travels through it. Increase the charge in a vacuum and the speed of light slows. Other fundamental constants also change. The fine structure constant is a function of the volume of particle-antiparticle pairs. This paper is a must read for the vacuum energy folks.
