Resonant non-gaussianity

By Raphael Flauger, E. Pajer. 2010

214 citations recorded by the source corpus.

We provide a derivation from first principles of the primordial bispectrum of scalar perturbations produced during inflation driven by a canonically normalized scalar field whose potential exhibits small sinusoidal modulations. A potential of this type has been derived in a class of string theory models of inflation based on axion monodromy. We use this model as a concrete example, but we present our derivations and results for a general slow-roll potential with superimposed modulations. We show analytically that a resonance between the oscillations of the background and the oscillations of the fluctuations is responsible for the production of an observably large non-Gaussian signal. We provide an explicit expression for the shape of this resonant non-Gaussianity. We show that there is essentially no overlap between this shape and the local, equilateral, and orthogonal shapes, and we stress that resonant non-Gaussianity is not captured by the simplest version of the effective field theory of inflation. We hope our analytic expression will be useful to further observationally constrain this class of models.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/487ea215d215bd3303b9f384ad417be87e2c2753

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. D. Baumann
2. M. Zaldarriaga
3. L. Senatore
4. E. Pajer
5. Xingang Chen
6. D. Green
7. Marco Peloso
8. E. Komatsu

In Nuclear and High Energy Physics

1. D. Baumann
2. Marco Peloso
3. E. Pajer
4. L. Senatore
5. Xingang Chen
6. M. Zaldarriaga
7. D. Green
8. Liam McAllister

Citations in the corpus

• On soft limits of inflationary correlation functions (2012, background): “mber of e-folds is taken to innity before taking q!0 (see e.g. [36{40]). This is related to the observation that q˝k 1;2 is not a sucient condition for satisfying the consistency relation (see e.g. [6,54,55]). Understanding these nite qeects can be important given that observations will only probe a”
• An ignoble approach to large field inflation (2010, background): “The precise computation in [18, 67, 68, 70, 71] is somewhat complicated.”
• Planck 2018 results. IX. Constraints on primordial non-Gaussianity (2019, background): “This periodic symmetry can cause resonances during inflation, imprinting logarithmically-spaced oscillations in the power spectrum, bispectrum and beyond (Flauger et al. 2010; Hannestad et al. 2010; Flauger & Pajer 2011).”
• A review of axion inflation in the era of Planck (2013, background): “ion to the background dynamics, these terms can imprint a very characteristic oscillating signal in all primordial correlators. The signal, induced by a resonance between background and perturbations [21, 74], has three parameters: the amplitude related to the size of non-perturbative eects; the fre”
• Phenomenology of a pseudo-scalar inflaton: naturally large nongaussianity (2011, background): “In [13], and also in [59], it was shown that axion monodromy models can give rise to large resonant-type nongaussianities [27, 28, 60, 44].”
• Primordial black holes and gravitational waves from parametric amplification of curvature perturbations (2019, background): “Non-Gaussianity is generated in this kind of models [73–75].”
• The (not so) squeezed limit of the primordial 3-point function (2011, methodology): “Reference [25] shows that this expression satisfies the consistency relation at leading order.”
• Planck 2015 results. XVII. Constraints on primordial non-Gaussianity (2015, unknown): “This periodicity can generate resonances in the inflationary fluctuations with logarithmically-spaced oscillations, creating imprints in the power spectrum, the bispectrum and trispectrum (Chen et al. 2008; Flauger et al. 2010; Hannestad et al. 2010; Flauger & Pajer 2011).”
• Planck2018 results (2018, background): “Oscillatory features can appear in multiple correlation functions (Chen et al. 2008; Meerburg et al. 2009; Flauger et al. 2010; Flauger & Pajer 2011; Achúcarro et al. 2011; Adshead et al. 2012; Achúcarro et al. 2014; Flauger et al. 2017a,b) (see, e.g., Chluba et al. (2015) for a recent review).”
• Exploring cosmic origins with CORE: Inflation (2016, background): “Periodic variations in 1(t) (for instance due to monodromy or small-scale structure in the scalar potential) can lead to a resonant enhancement of oscillatory features in the power spectrum or in the non-Gaussianity [148, 149].”
• Galaxy Bias and non-Linear Structure Formation in General Relativity (2011, background): “(10)One can construct examples were there is an intermediate “squeezed regime” over which the scaling is different than k(2) but for sufficiently large ratio the scaling needs to be k(2) [31, 32, 33, 34, 35, 36].”