In this paper, we review in detail different mechanisms of generation of large primordial
fluctuations and their implications for the production of primordial black holes (PBHs) and …

The pulsar timing array (PTA) collaborations have recently suggested the presence of a
gravitational wave background at nano-Hertz frequencies. In this paper, we explore potential …

The stochastic signal detected by pulsar timing arrays (PTAs) has raised great interest in
understanding its physical origin. Assuming the signal is a cosmological gravitational-wave …

The stochastic signal detected by NANOGrav, PPTA, EPTA, and CPTA can be explained by
the scalar-induced gravitational waves. In order to determine the scalar-induced …

We investigate the explicit role of negative local non-Gaussianity, f NL, in suppressing the
abundance of primordial black holes (PBHs) in the single-field model of Galileon inflation …

Recently released data from pulsar timing array (PTA) collaborations provide strong
evidence for a stochastic signal consistent with a gravitational-wave background, potentially …

Recently the international pulsar timing array collaboration has announced the first strong
evidence for an isotropic gravitational-wave background (GWB). We propose that rapid …

A stochastic gravitational wave background is a prediction of a number of astrophysical and
cosmological phenomena including early Universe cosmology. Recently, the NANOGrav …

Recently, several major pulsar timing array (PTA) collaborations have assembled strong
evidence for the existence of a gravitational-wave background at frequencies around the …

The recent detection of a stochastic signal in the NANOGrav 15-year dataset has aroused
great interest in uncovering its origin. However, the evidence for the Hellings-Downs …