Quebra dinâmica de simetria de Lorentz em um modelo de quatro férmions derivativo

Abstract

In this dissertation we investigate spontaneous Lorentz symmetry breaking in a 4-fermion derivative model. The essence of the spontaneous Lorentz symmetry breaking mechanism consists in the coupling of tensor fields through potentials in such a way that, in the minima of the potentials, these fields acquire expected values of non-trivial vacuum, thus introducing privileged space-time directions. For this model we calculate the effective potential in the context of zero temperature and finite temperature, we also investigate the conditions for symmetry restoration. Next, we calculate the corresponding effective action and show that the resulting potential is positively defined and has a continuous set of minima, as well as performing the induction of the second order kinetic action in the auxiliary field.