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 …

In this paper, we propose a novel mechanism in Bbb T 2-inflation to enhance the power
spectrum large enough to seed primordial black holes (PBHs) formation. To accomplish this …

In this Letter, we derive for the first time a characteristic three-peaked GW signal within the
framework of no-scale Supergravity, being the low-energy limit of Superstring theory. We …

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 …

Recent observations from several pulsar timing array (PTA) collaborations have unveiled
compelling evidence for a stochastic signal in the nanohertz band. This signal aligns …

In order to unravel the present situation of the PBH overproduction problem, our study
emphasizes the critical role played by the equation of state (EoS) parameter w within the …

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

The recent detection of a stochastic gravitational wave background (SGWB) at nanohertz
frequencies by pulsar timing arrays (PTAs) has sparked a flurry of interest. Beyond the …

We show that, when connected with monopoles, the flat D-flat direction breaking the local U
(1) BL symmetry as an extension of the minimal supersymmetric standard model can be …