Primordial blackholes and gravitational waves for an inflection-point model of inflation

Abstract

In this article we provide a new closed relationship between cosmic abundance of primordial gravitational waves and primordial blackholes originated from initial inflationary perturbations for inflection-point models of inflation where inflation occurs below the Planck scale. The current Planck constraint on tensor-to-scalar ratio, running of the spectral tilt, and from the abundance of dark matter content in the universe, we can deduce a strict bound on the current abundance of primordial blackholes to be within a range, $9.99712\times 10^{-3}<{\Omega }_{PBH}{h}^2<9.99736\times 10^{-3}$.

Comments: 7 pages, 3 figures, Revision accepted by Physics Letters B