Bigravity: a bimetric model of the Universe with variable constants,   inluding VSL (variable speed of light)
  The Universe, far to be homogenous, expands in large empty bubbles of the large-scale structure, but not in mass concentrations like galaxies, so that the Robertson-Walker solution does not fit. We suggest that a symmetry breaking occurred in a distant past, during the radiation-dominated era. Before, the three-dimensional hypersurface was invariant under the action of O(3) and the Robertson-Walker metric could be used. But this obliges the so-called constants and physics, length and time scale factors to be involved through a generalized gauge process, which is built. The subsequent variation of the speed of light solves the horizon problem, while the Planck barrier disappears 
Jean Pierre Petit and Gilles d'Agostini