English

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

Cosmology and Nongalactic Astrophysics 2014-01-16 v2 General Relativity and Quantum Cosmology High Energy Physics - Theory

Abstract

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.

Keywords

Cite

@article{arxiv.1106.1462,
  title  = {The (not so) squeezed limit of the primordial 3-point function},
  author = {Paolo Creminelli and Guido D'Amico and Marcello Musso and Jorge Noreña},
  journal= {arXiv preprint arXiv:1106.1462},
  year   = {2014}
}

Comments

18 pages, 2 figures. v2: minor changes to match JCAP published version

R2 v1 2026-06-21T18:19:12.724Z