Generalized local ansatz for scale-dependent primordial non-Gaussianities and future galaxy surveys

Daisuke Yamauchi, Shuichiro Yokoyama, Tomo Takahashi

We revisit a possible scale-dependence of local-type primordial non-Gaussianities induced by super-horizon evolution of scalar field perturbations. We develop the formulation based on δN formalism and derive the generalized form of the local-type bispectrum and also trispectrum which allows us to implement the scale-dependence and suitably compare model prediction with observational data. We propose simple but phenomenologically meaningful expressions, which encompass the information of a wide range of physically motivated models. We also formulate large-scale power spectrum and bispectrum of biased objects in the presence of the scale-dependent primordial non-Gaussianities. We perform the Fisher analysis for future galaxy surveys and give the projected constraints on the parameters of the generalized local-form of primordial non-Gaussianities.

Publications of the Astronomical Society of Japan

75

1

S181

S195

https://doi.org/10.1093/pasj/psab108

2108.12123