Accounting for scalar non-Gaussianity in secondary gravitational waves

Understand

It is well known that enhancement in the primordial scalar perturbations over small scales generates detectable amplitudes of secondary gravitational waves (GWs), by sourcing the tensor perturbations at the second order.

• These stochastic gravitational waves are expected to carry the imprints of primordial non-Gaussianities.
• The scalar bispectrum that is typically produced in models of inflation leading to significant secondary GWs is non-trivial and highly scale dependent.
• In this work, we present a method to account for such general scale dependent scalar bispectrum arising from inflationary models in the calculation of the spectral density of secondary GWs.