Poincar\'e, Scale and Conformal Symmetries: Gauge Perspective and Cosmological Ramifications

Understand

In the first part of the thesis we focus on local symmetries.

• We review a self-consistent framework that we employed in order to discuss the dynamics of the theories of interest.
• Its merit lies in that we can make the symmetry group act internally and thus be effectively separated from coordinate transformations.
• We investigate under which conditions it is not needed to introduce extra compensating fields to make relativistic as well as nonrelativistic theories invariant under local symmetries and more precisely under scale transformations.