PBHs and GWs from 𝕋2^{2}-inflation and NANOGrav 15-year data

Jul 13, 2023
8 pages
Published in:
  • JCAP 08 (2023) 067
  • Published: Aug 25, 2023
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Abstract: (IOP)
In this paper, we propose a novel mechanism in 𝕋2^{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 𝕋2^{2} = TμνTμν 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. In addition, the energy spectrum associated with SIGWs can be compatible with the recent NANOGrav 15-year stochastic gravitational wave detection and fall into the sensitivity range of other forthcoming GW observatories.
Note:
  • 8 pages, 7 figures, and one table, references added, accepted by JCAP
  • gravitational waves and CMBR polarization
  • inflation
  • primordial black holes