Possible Connection between Dark Energy and Electromagnetic Interactions
  This paper has been withdrawn by the authors. Please see [arXiv:1208.3224]. We investigate a model where dark energy is caused by the photon field coupling to gravitation. The cosmological background expectation value of the electromagnetic scalar potential generates the Planck mass as well as causing an exponential expansion which is identified with dark energy. The Higgs-like mechanism for the vector potential predicts the photon mass to be exactly zero. 
Metin Arik, N. Katirci
gr-qc hep-th