Signatures of primordial non-Gaussianities in the matter power-spectrum and bispectrum: the time-RG approach
- Dipartimento di Fisica ''G. Galilei'', Università degli Studi di Padova, via Marzolo 8, I-35131 Padova (Italy)
- Instituto de Física Teórica, UNESP — Universidade Estadual Paulista, Caixa Postal 70532-2, 01156-970 São Paulo, SP (Brazil)
- INFN, Sezione di Padova, via Marzolo 8, I-35131 Padova (Italy)
We apply the time-renormalization group approach to study the effect of primordial non-Gaussianities in the non-linear evolution of cosmological dark matter density perturbations. This method improves the standard perturbation approach by solving renormalization group-like equations governing the dynamics of gravitational instability. The primordial bispectra constructed from the dark matter density contrast and the velocity fields represent initial conditions for the renormalization group flow. We consider local, equilateral and folded shapes for the initial non-Gaussianity and analyze as well the case in which the non-linear parameter f{sub NL} parametrizing the strength of the non-Gaussianity depends on the momenta in Fourier space through a power-law relation, the so-called running non-Gaussianity. For the local model of non-Gaussianity we compare our findings for the power-spectrum with those of recent N-body simulations and find that they accurately fit the N-body data up to wave-numbers k ∼ 0.25 h/Mpc at z = 0. We also present predictions for the (reduced) matter bispectra for the various shapes of non-Gaussianity.
- OSTI ID:
- 22273010
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 03; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Planck 2015 results: XVII. Constraints on primordial non-Gaussianity
Shape of primordial non-Gaussianity and the CMB bispectrum