We investigate the constraint on the abundance of primordial black holes (PBHs) and the spectral index n of primeval density perturbations given by the ionizing photon background at the epoch of reionization. Within the standard inflationary cosmogony, we show that the spectral index n of the power-law power spectrum of primeval density perturbations should be n <1.27. Since the universe is sti...

1 Graduate Program in Life Sciences, Microbiology and Immunology Program, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America, 2 Department of Microbial Pathogenesis, Dental School, University of Maryland, Baltimore, Maryland, United States of America, 3 Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryla...

We show that deviations of the quantum state of the inflaton from the thermal vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum dynamics of the inflaton in such a state produces corrections to the inflationary fluctuations, which may be observable. Because these effects originate from IR physics below the Planck scale, they will dominate over any trans-Planckian impr...