In our previous work it has been shown the possibility to use the Aharonov-Anandan invariant as a tool in the analysis of disparate systems, including Hawking and Unruh effects, as well as graphene physics and thermal states. We show that the vacuum
condensation, characterizing such systems, is also related with geometric phases and we analyze the properties of the geometric phase of systems represented by mixed state and undergoing a nonunitary evolution. In particular, we consider two level atoms accelerated by an external potential and interacting with a thermal state. We propose the realization of Mach-Zehnder interferometers which can prove the existence of the Unruh effect and can allow very precise measurements of temperature.
We discuss flavor charges and states for interacting mixed neutrinos in QFT. We show that the Pontecorvo states are not eigenstates of the flavor charges. This implies that their use in describing the flavor neutrinos produces a violation of lepton c
harge conservation in the production/detection vertices. The flavor states defined as eigenstates of the flavor charges give the correct representation of mixed neutrinos in charged current weak interaction processes.
We report on the recent result that a contribution to the dark energy can be achieved by the vacuum condensate induced by neutrino mixing phenomenon.
