SAMPAIO, T. A. S. M.; http://lattes.cnpq.br/1217707310609408; SAMPAIO, Thiago Alves de Sá Muniz.
Resumo:
Based on the motivation that some quantum gravity theories predict the Lorentz
Invariance Violation (LIV) around Planck-scale energy levels, we propose the construction
of new formalisms that addresses the possible e ects of LIV in Electrodynamics and in
Linearized Gravity. These formalisms are based on e ective eld theories capable to
modify the commonly used lagrangians through high-derivative arbritrary mass dimension
terms that includes a constant background eld controlling the intensity of LIV in the
models. This produces modi cations in the equations of motion and in the dispersion
relations of the theories in a manner that is similar to the Myers-Pospelov approach. We
expect that these operators could be able to describe the typical LIV of the fundamental
quantum gravity high-energy scales. We also studied theoretical aspects related to the
consistency of the modi ed Electrodynamics through the stability, the causality and the
unitarity, with the photon Feynman propagator computation in the presence of LIV. Then
we have studied the phenomenological context of the models considering time delay e ects
between two photons and between two gravitons, as well as e ects of birefringence between two photons, using the data coming from astrophysical events of electromagnetic waves emissions coming from gamma-ray bursts, as well as the gravitational waves emissions detected so far. We also consider the time delay phenomena due to the presence of gravitational lenses. Finally, we discuss the experimental limits on LIV around the Planck energy scale.