Citation

BibTex format

@article{Jazayeri:2023:10.1007/jhep12(2022)137,
author = {Jazayeri, S and Renaux-Petel, S},
doi = {10.1007/jhep12(2022)137},
journal = {The Journal of High Energy Physics},
title = {Cosmological bootstrap in slow motion},
url = {http://dx.doi.org/10.1007/jhep12(2022)137},
volume = {2022},
year = {2023}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Speed matters. How the masses and spins of new particles active during inflation can be read off from the statistical properties of primordial density fluctuations is well understood. However, not when the propagation speeds of the new degrees of freedom and of the curvature perturbation differ, which is the generic situation in the effective field theory of inflationary fluctuations. Here we use bootstrap techniques to find exact analytical solutions for primordial 2-,3- and 4-point correlators in this context. We focus on the imprints of a heavy relativistic scalar coupled to the curvature perturbation that propagates with a reduced speed of sound cs, hence strongly breaking de Sitter boosts. We show that akin to the de Sitter invariant setup, primordial correlation functions can be deduced by acting with suitable weight-shifting operators on the four-point function of a conformally coupled field induced by the exchange of the massive scalar. However, this procedure requires the analytical continuation of this seed correlator beyond the physical domain implied by momentum conservation. We bootstrap this seed correlator in the extended domain from first principles, starting from the boundary equation that it satisfies due to locality. We further impose unitarity, reflected in cosmological cutting rules, and analyticity, by demanding regularity in the collinear limit of the four-point configuration, in order to find the unique solution. Equipped with this, we unveil that heavy particles that are lighter than H/cs leave smoking gun imprints in the bispectrum in the form of resonances in the squeezed limit, a phenomenon that we call the low speed collider. We characterise the overall shape of the signal as well as its unusual logarithmic mass dependence, both vividly distinct from previously identified signatures of heavy fields. Eventually, we demonstrate that these features can be understood in a simplified picture in which the heavy field is integrated out, albeit
AU  - Jazayeri,S
AU  - Renaux-Petel,S
DO  - 10.1007/jhep12(2022)137
PY  - 2023///
SN  - 1029-8479
TI  - Cosmological bootstrap in slow motion
T2  - The Journal of High Energy Physics
UR  - http://dx.doi.org/10.1007/jhep12(2022)137
UR  - http://hdl.handle.net/10044/1/112615
VL  - 2022
ER  -
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