5 papers
Time as a test-field: the no-boundary universe in motion and a smooth radiation bounce
Federico Piazza, Siméon Vareilles
The proper time of an observer can be introduced as a degree of freedom in quantum cosmology, additional to the existing fields. We review two arguments for using the Schrödinger…
Moving superfluids in the rotating universe
Jose Beltrán Jiménez, Federico Piazza, Javier Vecino
We study homogeneous cosmological models featuring shift-symmetric scalar fields (or, superfluids) in relative motion. In the presence of anisotropy this universe generally feature…
On the fate of spacetime singularities
Federico Piazza
I investigate spacetime singularities from the point of view of the wavefunction of the universe. In order to extend the classical notion of geodesic incompleteness one has to incl…
Modified Microcausality from Perturbation Theory
Giordano Cintia, Federico Piazza, Samuel Ramos
Relativistic microcausality is the statement that local field operators commute outside the light-cone. This condition is known to break down in low-energy effective theories, such…
Cosmological perturbations meet Wheeler DeWitt
Federico Piazza, Siméon Vareilles
We study approximate solutions of the Wheeler DeWitt (WdW) equation and compare them with the standard results of cosmological perturbation theory. In mini-superspace, we introduce…