Bipartite-Finsler spaces and the bumblebee model

We present a proposal to include Lorentz-violating effects in gravitational field by means of the Finsler geometry. In the Finsler set up, the length of an event depends both on the point and the direction in the space-time. We briefly review the bumblebee model, where the Lorentz violation is induced by a spontaneous symmetry breaking due to the bumblebee vector field.The main geometrical concepts of the Finsler geometry are outlined. Using a Finslerian Einstein-Hilbert action we derive the bumblebee action from the bipartite Finsler function with a correction to the gravitational constant.