We review numerous arguments for primordial black holes (PBHs) based on observational
evidence from a variety of lensing, dynamical, accretion and gravitational-wave effects. This …

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 …

Abstract Recently, the NANOGrav, PPTA, EPTA, and CPTA Collaborations independently
reported their evidence of the Stochastic Gravitational Waves Background (SGWB). While …

Pulsar timing arrays gathered evidence of the presence of a gravitational wave background
around nHz frequencies. If the gravitational wave background was induced by large and …

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 …

The stochastic gravitational wave background (SGWB) detected recently by the pulsar timing
arrays (PTAs) observations may have cosmological origins. In this work we consider a …

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 …

Recently, multiple pulsar timing array collaborations have presented compelling evidence
for a stochastic signal at nanohertz frequencies, potentially originating from cosmic strings …

There is controversy surrounding the origin and evolution of our universe's largest
supermassive black holes (SMBHs). In this study, we consider the possibility that some of …