By: Carla Sofia Carvalho
At: Complexo Interdisciplinar, Anfiteatro
We consider the mechanism of spontaneous symmetry breaking of a bulk vector field to study signatures of bulk dimensions invisible to the standard model confined to the brane. By assigning a non-vanishing vacuum expectation value to the vector field, a direction is singled out in the bulk vacuum, thus breaking the bulk Lorentz symmetry.
We present the condition for induced Lorentz symmetry on the brane, as phenomenologically required. We also show that the requirement for Lorentz symmetry is related to the value of the cosmological constant observed on the brane.