The (not so) squeezed limit of the primordial 3-point function

By P. Creminelli, Guido D'Amico, M. Musso, J. Noreña. 2011

146 citations recorded by the source corpus.

We prove that, in a generic single-field model, the consistency relation for the 3-point function in the squeezed limit receives corrections that vanish quadratically in the ratio of the momenta, i.e. as (k L/k S) 2. This implies that a detection of a bispectrum signal going as 1/k L 2 in the squeezed limit, that is suppressed only by one power of k L compared with the local shape, would rule out all single-field models. The absence of this kind of terms in the bispectrum holds also for multifield models, but only if all the fields have a mass much smaller than H. The detection of any scale dependence of the bias, for scales much larger than the size of the haloes, would disprove all single-field models. We comment on the regime of squeezing that can be probed by realistic surveys. © 2011 IOP Publishing Ltd and SISSA.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/507b17715061698585a8bee46710dcb7501861e0

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Citations in the corpus

On soft limits of inflationary correlation functions (2012, background): “See [6] for an alternative derivation of this result.”
An infinite set of Ward identities for adiabatic modes in cosmology (2013, background): “It has been argued recently that the order q behavior of soft correlators is also fixed by consistency relations [47, 70].”
Testing Inflation with Large Scale Structure: Connecting Hopes with Reality (2014, background): “The scaling of the f loc NL-dependent term approaches 1/k 2 at low-k making it a dramatic signature of non-Gaussian primordial statistics that, if detected, would rule out single-clock inflationary models [81].”
Conformal consistency relations for single-field inflation (2012, background): “As the conformal variation of the 2-point function trivially vanishes, we recover the known result that the 3-point function does not contain terms going as 1/q2 in the squeezed limit [13].”
The clustering of galaxies in the SDSS-III DR9 Baryon Oscillation Spectroscopic Survey: constraints on primordial non-Gaussianity (2012, background): “Komatsu (2010) and Creminelli et al. (2011) have shown that, for standard, single-field inflation, the amplitude of the bispectrum in the “squeezed” limit becomes vanishingly small, and thus any detected scale-dependent bias at large-scales would disprove all single-field models, subject to the…”
Signature of supersymmetry from the early universe (2011, background): “Here, single-field inflation corresponds to α = 1 [9], while multiple light fields with m H can lead to non-Gaussianity with α = 3 [10].”