Constraining quantum collapse inflationary models with current data: The semiclassical approach

PICCIRILLI, MARÍA PÍA; LEON, GABRIEL; LANDAU, SUSANA J.; BENETTI, MICOL; SUDARSKY, DANIEL

INTERNATIONAL JOURNAL OF MODERN PHYSICS D

WORLD SCIENTIFIC PUBL CO PTE LTD

Año: 2018 vol. 28

0218-2718

The hypothesis of the self-induced collapse of the inflaton wave function was introduced as a candidate for  the physical process responsible for the emergence of inhomogeneity and anisotropy at all scales.  In particular, we consider  different proposal for the precise form of the dynamics of the inflaton wave function: i) the   GRW-type collapse schemes proposals  based on spontaneous   individual  collapses   which   generate non-vanishing expectation  values   of  various   physical quantities  taken as emph{ansatz}  modifications   of the standard inflationary scenario; ii) the proposal   based on   a Continuous Spontaneous Localization (CSL)   type modification of the Schrödinger   evolution  of   the inflaton wave function, based on a  natural choice  of collapse  operator. We perform a  systematic    analysis   within  the    semi-classical gravity approximation,  of  the  standing of those  models considering  a full quasi-de sitter expansion scenario. We note that  the predictions for the Cosmic Microwave Background (CMB) temperature and polarization spectrum differ slightly from those of the standard cosmological model. We  also analyse these proposals with a Bayesian model comparison using recent CMB and Baryonic Acoustic Oscillations (BAO) data. Our results show a moderate preference of the joint CMB and BAO data for one of the studied collapse schemes model over the LCDM one, while there is no preference when only CMB data are considered. Additionally, analysis using CMB data provide the same Bayesian evidence for both the CSL and standard models, i.e. the data have not preference between the simplicity of the LCDM model and the complexity of the collapse scenario.