Double peaks of gravitational wave spectrum induced from inflection point inflation

Abstract

We investigate the possibility of inducing the gravitational waves (GWs) with double peak energy spectrum from primordial scalar perturbations in inflationary models with three inflection points. Here the inflection points can be generated from a polynomial potential or generated from a Higgs-like $$\phi ^4$$ ϕ 4 potential with the running of quartic coupling. In such models, the inflection point at large scales predicts the scalar spectral index and tensor-to-scalar ratio to be consistent with current CMB constraints, and the other two inflection points generate two large peaks in the scalar power spectrum at small scales, which can induce GWs with a double peak energy spectrum. We find that for some choices of the parameters the double peak spectrum can be detected by future GW detectors, and one of the peaks around $$f\simeq 10^{-9}{-}10^{-8}$$ f ≃ 10 - 9 - 10 - 8 Hz can also explain the recent NANOGrav signal. Moreover, the peaks of the power spectrum allow for the generation of primordial black holes, which accounts for a significant fraction of dark matter.

Induced gravitational waves from multi-sound speed resonances during cosmological inflation

“…Let us mention that the double peak structure of the primordial density power spectrum were also explored in refs. [76][77][78][79][80][81]. Additionally, on top of the main features of the induced GW spectrum, we will show that there are certain fine structures produced by interactions of the multiple peaks of the JCAP08(2022)051 source spectrum or the oscillatory modulation of the envelope of particular resonating modes.…”

Primordial black holes and gravitational waves in teleparallel Gravity

“…The NANOGrav measurements preferred ranges of parameters A GW B [87] while according to [88] α = (5 − γ) ∈ [−1.5, 0.5], f yr is best estimated to f yr ≃ 3.1 × 10 −8 and H 0 is given by H 0 ≡ 100h km/s/M pc. In Fig.…”

Scalar induced gravitational waves review

“…For example, the induced GWs from various inflationary models can be found in Refs. [98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113][114][115][116] and [62,114,117,118] in the context of Higgs inflation. In particular, the large induced GW counterpart to PBH as the totality of dark matter is studied in Refs.…”