Abstract
Long-short mode coupling during inflation, encoded in the squeezed bispectrum of curvature perturbations, induces a dependence of the local, small-scale power spectrum on long-wavelength perturbations, leading to a scale-dependent halo bias. While this scale dependence is absent in the large-scale limit for single-field inflation models that satisfy the consistency relation, certain models such as resonant non-Gaussianity show a peculiar behavior on intermediate scales. We reconsider the predictions for the halo bias in this model by working in Conformal Fermi Coordinates, which isolate the physical effects of long-wavelength perturbations on short-scale physics. We find that the bias oscillates with scale with an envelope similar to that of equilateral non-Gaussianity. Moreover, the bias shows a peculiar modulation with the halo mass. Unfortunately, we find that upcoming surveys will be unable to detect the signal because of its very small amplitude. We also discuss non-Gaussianity due to interactions between the inflaton and massive fields: our results for the bias agree with those in the literature.
Original language | English |
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Article number | 003 |
Journal | Journal of Cosmology and Astroparticle Physics |
Volume | 2018 |
Issue number | 9 |
DOIs | |
Publication status | Published - 3 Sept 2018 |
Funding
It is a pleasure to thank Lorenzo Bordin, Paolo Creminelli, Dionysios Karagiannis, Titouan Lazeyras, Hayden Lee, Michele Liguori and Marko Simonovićfor useful discussions. G. C. and F. S. acknowledge support from the Starting Grant (ERC-2015-STG 678652)“GrInflaGal” from the European Research Council. E. P. is supported by the Delta-ITP consortium, a program of the Netherlands Organization for Scientific Research (NWO) that is funded by the Dutch Ministry of Education, Culture and Science (OCW). This work is part of the research programme VIDI with Project No. 680-47-535, which is (partly) financed by the Netherlands Organisation for Scientific Research (NWO).
Keywords
- ination
- power spectrum