PBHs and GWs from $\mathbb{T}^2$-inflation and NANOGrav 15-year data

Understand

In this paper, we propose a novel mechanism in $\mathbb{T}^2$-inflation to enhance the power spectrum large enough to seed primordial black holes (PBHs) formation.

• To accomplish this, we consider the coupling function between the inflaton field and $\mathbb{T}^2= T_{\mu \nu}T^{\mu \nu}$ term.
• PBHs formed within this scenario can contribute partially or entirely to dark matter (DM) abundance.
• Furthermore, the amplification in the scalar power spectrum will concurrently produce significant scalar-induced gravitational waves (SIGWs) as a second-order effect.