Trispectrum estimator in equilateral type non-Gaussian models

Shuntaro Mizuno, Kazuya Koyama

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We investigate an estimator to measure the primordial trispectrum in equilateral type non-Gaussian models such as k-inflation, single field DBI inflation and multi-field DBI inflation models from Cosmic Microwave Background (CMB) anisotropies. The shape of the trispectrum whose amplitude is not constrained by the bispectrum in the context of effective theory of inflation and k-inflation is known to admit a separable form of the estimator for CMB anisotropies. We show that this shape is 87% correlated with the full quantum trispectrum in single field DBI inflation, while it is 33% correlated with the one in multi-field DBI inflation when curvature perturbation is originated from purely entropic contribution. This suggests that gequil NL , the amplitude of this particular shape, provides a reasonable measure of the non-Gaussianity from the trispectrum in equilateral non-Gaussian models. We relate model parameters such as the sound speed, cs and the transfer coefficient from entropy perturbations to the curvature perturbation, T RS with gequil NL , which enables us to constrain model parameters in these models once gequil NL is measured in WMAP and Planck.

Original languageEnglish
Title of host publicationProceedings of the 20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010
Pages278-281
Number of pages4
Publication statusPublished - 2010
Externally publishedYes
Event20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010 - Kyoto
Duration: 2010 Sep 212010 Sep 25

Other

Other20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010
CityKyoto
Period10/9/2110/9/25

    Fingerprint

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

Mizuno, S., & Koyama, K. (2010). Trispectrum estimator in equilateral type non-Gaussian models. In Proceedings of the 20th Workshop on General Relativity and Gravitation in Japan, JGRG 2010 (pp. 278-281)