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 (kL/k S)2. This implies that a detection of a bispectrum signal going as 1/kL2 in the squeezed limit, that is suppressed only by one power of kL 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.
The (not so) squeezed limit of the primordial 3-point function / Creminelli, Paolo; D'Amico, Guido; Musso, Marcello; Norem̃a, Jorge. - In: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. - ISSN 1475-7516. - 2011:11(2011), pp. 038-038. [10.1088/1475-7516/2011/11/038]
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