Inflationary and hence quantum origin of primordial perturbations is on a firmer ground than ever post the BICEP2 observations of primordial gravitational waves. One crucial ingredient of the success of this paradigm rests on explaining the observed classicality of cosmological inhomogeneities despite their quantum origin. Although decoherence provides a partial understanding of this issue, the question of single outcome motivates the analysis of quantum collapse models in cosmological context which generically modify the dynamics of primordial perturbations and hence can leave their imprints on observables. We revisit one such recently proposed working model of classicalization by spontaneous collapse [S. Das et al., Phys. Rev. D 88, 085020 (2013)] in the light of BICEP2 observations to look for possible modifications to tensor power spectra and their implications. We show that it can potentially change the consistency relation of single-field models, and a precise measurement of $n_T$ and its running could serve as a test of such dynamics in the early universe.

• Received 1 May 2014

DOI:https://doi.org/10.1103/PhysRevD.90.043503