# The shape of non-Gaussianities

@article{Babich2004TheSO, title={The shape of non-Gaussianities}, author={Daniel Babich and Paolo Creminelli and Matias Zaldarriaga}, journal={Journal of Cosmology and Astroparticle Physics}, year={2004}, volume={2004}, pages={009-009} }

We study the dependence on the configuration in momentum space of the primordial three-point function of density perturbations in several different scenarios: standard slow-roll inflation, curvaton and variable decay models, ghost inflation, models with higher derivative operators and the DBI model of inflation. We define a cosine between the distributions using a measure based on the ability of experiments to distinguish between them. We find that models fall into two broad categories with…

## 430 Citations

Large non-Gaussianities in single-field inflation

- Computer Science
- 2007

While adding features to a potential can improve the fit to the two-point function, these are generically associated with a greatly enhanced signal at the three-point level, which may lead to a consistency check on models of inflation with non-smooth potentials.

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We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including…

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We investigate the primordial non-Gaussianities from the trispectra in multi-field inflation models, which can be seen as generalization of multi-field k-inflation and multi-DBI inflation. We derive…

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- Physics
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We study the bispectrum of the curvature perturbation on uniform energy density hypersurfaces in models of inflation with two scalar fields evolving simultaneously. In the case of a separable…

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- Physics
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We consider whether the non-Gaussian scale-dependent halo bias can be used not only to constrain the local form of non-Gaussianity but also to distinguish among different shapes. In particular, we…

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- Computer Science
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Using the recently developed Effective Field Theory of Inflation, it is shown that it is possible to impose an approximate parity symmetry and an approximate continuos shift symmetry on the inflaton fluctuations that allow a unique quartic operator, while approximately forbidding all the cubic ones.

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- 2006

We develop a method for constraining the level of non-Gaussianity of density perturbations when the three-point function is of the 'equilateral' type. Departures from Gaussianity of this form are…

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Heavy scalar fields can undergo an instability during inflation as a result of their kinetic couplings with the inflaton. This is known as the geometrical destabilization of inflation, as it relies…

Consistency relation and non-Gaussianity in a Galileon inflation

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We study a particular Galileon inflation in the light of Planck2015 observational data in order to constraint the model parameter space. We study the spectrum of the primordial modes of the density…

Testing an Inflation Model with Nonminimal Derivative Coupling in the Light of PLANCK 2015 Data

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We study the dynamics of a generalized inflationary model in which both the scalar field and its derivatives are coupled with the gravity. We consider a general form of the nonminimal derivative…

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