2023/04/12 by Barnali Das, H. V. Ragavendra, Das, Barnali +1
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Theory (hep-th) #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2304.05941
openalex publication_date 2023/04/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Primordial non-Gaussianity arising from inflationary models is a unique probe of non-trivial dynamics of the inflaton field and its interactions with other fields. Often when examining and constraining the scalar non-Gaussianity arising from inflation, certain templates are adopted for the scalar non-Gaussianity parameter f_\rm NL, in classifying their behaviors in terms of wavenumbers. The current constraints from cosmic microwave background (CMB) on such templates of f_\rm NL are weak and provide rather large bounds on their amplitudes. In this work, we explore a different method of constraining f_\rm NL through their effect on the scalar power. We compute the correction to the scalar power due to f_\rm NL while accounting for its generic scale dependence. We then compute the angular power spectrum of CMB arising from such non-Gaussian corrections to explore possible imprints. We initially illustrate this method using the conventional templates of f_\rm NL such as local, equilateral and orthogonal types, with and without the running of the parameter. We further employ this method to an oscillatory form of f_\rm NL and lastly on a realistic model of inflation proposed by Starobinsky. Though this method does not improve much on the constraints on the first three templates of f_\rm NL, it provides interesting insights on models that do not conform to these templates. We infer that the non-Gaussian correction to the spectrum can be sensitive to model parameters that are degenerate at the level of the original power spectrum. Hence, this method of computing indirect imprints of f_\rm NL on angular power spectrum of CMB provides a new avenue to explore primordial scalar non-Gaussianity and possibly constrain them effectively.