Review of local non-Gaussianity from multi-field inflation

By C. Byrnes, Kiwoon Choi. 2010

182 citations recorded by the source corpus.

We review models which generate a large non-Gaussianity of the local form. We first briefly consider three models which generate the non-Gaussianity either at or after the end of inflation; the curvaton scenario, modulated (p)reheating, and an inhomogeneous end of inflation. We then focus on ways of generating the non-Gaussianity during inflation. We derive general conditions which a product or sum separable potential must satisfy in order to generate a large local bispectrum during slow-roll inflation. As an application, we consider two-field hybrid inflation. We then derive a formalism not based on slow roll which can be applied to models in which the slow-roll parameters become large before inflation ends. An exactly soluble two-field model is given in which this happens. Finally, we also consider further non-Gaussian observables, a scale dependence of fNL and the trispectrum.

Subfields: Astronomy and Astrophysics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/98df8ab56191b74076cc80e705ab8bc9f2686a29

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. L. Senatore
2. M. Zaldarriaga
3. Xingang Chen
4. D. Green
5. D. Baumann
6. A. Banday
7. H. Eriksen
8. Uros Seljak

In Statistical and Nonlinear Physics

1. L. Senatore
2. M. Zaldarriaga
3. E. Shellard
4. J. Fergusson
5. Will Handley
6. A. Banday
7. D. Green
8. M. Liguori

Citations in the corpus

• Testing Inflation with Large Scale Structure: Connecting Hopes with Reality (2014, background): “For reviews of multiple field inflation models, including several which are not discussed here, see for example [24, 25].”
• Constraining primordial non-Gaussianity with future galaxy surveys (2011, background): “This changes however in most generalisations: many models, and especially multi-field inflation, produce non-Gaussianities (see e.g. the recent review by Byrnes & Choi 2010).”
• Large-Angle Anomalies in the CMB (2010, background): “Moreover, many inflationary models predict small deviations from Gaussianity; these are described in other contributions to this volume [9, 10].”
• Planck 2018 results. IX. Constraints on primordial non-Gaussianity (2019, methodology): “(3) mainly 2 See, e.g., Byrnes & Choi (2010) for a review on this type of model in the context of primordial NG.”
• Primordial bispectrum from multifield inflation with nonminimal couplings (2012, background): “) On the other hand, much as in [15, 27, 29, 30], we find a strong sensitivity of the magnitude of the bispectrum to the fields’ initial conditions.”
• Infrared effects in inflationary correlation functions (2010, background): “Even where a terminal vacuum can be selected in advance, it was shown by Byrnes, Choi and Hall that the final fluctuations may depend sensitively on the path by which the fields arrive at the minimum [134, 135] (reviewed in [136]).”