Primordial power spectrum from an objective collapse mechanism: the simplest case

OCAMPO, MARTIN MIGUEL; PALERMO, OCTAVIO; LEÓN, GABRIEL; BENGOCHEA, GABRIEL R.

Buenos Aires

Workshop; Giambiagi Winter School on Cosmology; 2023

International Centre for Theoretical Physics (ICTP) and Depto. de Física (UBA)

In this presentation we will analyze the physical origin of the primordial inhomogeneities during the inflation era. The proposed framework is based on semiclassical gravity, in which one only focuses on quantizing the matter fields, but the spacetime metric is always treated in a classical manner. The objective collapse mechanism is based on the Continuous Spontaneous Localization (CSL) model, and we apply it to the wave function associated to the inflaton field. The collapse given by the CSL model provides a satisfactory mechanism of breaking the initial symmetries of the Bunch-Davies vacuum. Additionally, we obtain a primordial spectrum that has the same distinctive features as the standard one, and which is consistent with the observations from the Cosmic Microwave Background (CMB). The novel aspect in this work is that the constructed CSL model arises from the simplest choices for the collapse parameter and operator.