Gravitational theories with augmented covariance.

Toller M.
  Mercoledì 13/09   09:00 - 13:00   Aula A203   III - Astrofisica
We summarize some recent progress in the construction of gravitational theories with a covariance group "augmented" with respect to the Lorentz group. We briefly recall the old arguments that suggest the choice of the augmented group $GL(4, R)$. A theory covariant under the symplectic subgroup $Sp(4, R)$ has been developed recently. A complete theory fully covariant under $GL(4, R)$ is not yet available. Presumably, it will include some quantum concepts, in particular the vacuum states are described by vectors in a Hilbert space. The unitary irreducible representation of the covariance group operating in this space is briefly described.