Second-Order Cosmological Perturbations from Inflation

By V. Acquaviva, N. Bartolo, S. Matarrese, A. Riotto. 2002

564 citations recorded by the source corpus.

We present the first computation of the cosmological perturbations generated during inflation up to second order in deviations from the homogeneous background solution. Our results, which fully account for the inflaton self-interactions as well as for the second-order fluctuations of the background metric, provide the exact expression for the gauge-invariant curvature perturbation bispectrum produced during inflation in terms of the slow-roll parameters or, alternatively, in terms of the scalar spectral $n_S$ and and the tensor to adiabatic scalar amplitude ratio $r$. The bispectrum represents a specific non-Gaussian signature of fluctuations generated by quantum oscillations during slow-roll inflation. However, our findings indicate that detecting the non-Gaussianity in the cosmic microwave background anisotropies emerging from the second-order calculation will be a challenge for the forthcoming satellite experiments.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/172c4375284cfe77efed5b99f3d5e8a618179c25

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

In Nuclear and High Energy Physics

Citations in the corpus

Signatures of Initial State Modifications on Bispectrum Statistics (2009, unknown): “40 44 v2 [ he p- th ] Contents”
General CMB and primordial bispectrum estimation: Mode expansion, map making, and measures of F NL (2009, background): “01 [1, 2], possessing a characteristic scale-invariant local shape.”
Observational signatures and non-Gaussianities of general single-field inflation (2006, background): “The elegant, gauge invariant calculation of the non-Gaussianities for slow-roll models appeared first in [7, 8].”
Primordial non-Gaussianities in single-field inflation (2005, unknown): “We obtain an explicit expression for the three-point correlation function in a self-consistent approximation scheme where the expansion rate varies slowly, analogous to the slow-roll limit in standard, singlefield inflation.”
DBI in the sky (2004, methodology): “ar X”
Primordial Non-Gaussianities from Inflation Models (2010, background): “4 A no-go theorem Simplest inflation models generate negligible amount of non-Gaussianities that are well below our current experimental abilities [47, 48].”
Gravitational Wave Spectrum Induced by Primordial Scalar Perturbations (2007, background): “The second-order Einstein tensor and energy-momentum tensor are [15] G (2)i j = a −2 [”
Gauge fields and inflation (2012, background): “Therefore, in single-field slow-roll inflation, non-Gaussianity is predicted to be unobservably small [24, 25], while it can be significant in models with multiple fields, higherderivative interactions or nonstandard initial states [21, 26, 27].”
Non-Gaussianities in single field inflation and their optimal limits from the WMAP 5-year data (2009, background): “This means that time translations are spontaneously broken, and that therefore there is a Goldstone boson associated with this symmetry breaking.”