Non-relativistic Cosmological Collider Signals
Abstract
We investigate a non-relativistic realization of the boostless cosmological collider in a scenario where inflationary interactions are mediated by a massive tilted-ghost spectator field. Unlike standard boostless collider constructions, in which the characteristic non-Gaussian signatures are mainly generated by boost-breaking interaction vertices, the dominant effect in the present framework arises directly from the propagation of the spectator modes. Non-relativistic corrections deform the bulk mode functions, inducing a tilt that modifies the in-in correlators and generates a distinctive collider signal. The resulting squeezed-limit non-Gaussianity reproduces the qualitative structure of boostless cosmological-collider signals while originating from a fundamentally different dynamical mechanism. A central feature of the construction is the emergence of an effective chemical-potential-like parameter that controls the relative weight of the two late-time oscillatory branches. However, the tilted-ghost mode exhibits distinctive dynamical features and does not correspond to a conventional chemical-potential deformation. Depending on the sign of the tilt, the corresponding non-Gaussian signal can be either enhanced or suppressed. We show that the tilted-ghost scenario provides a simple effective framework in which boostless-collider phenomenology and chemical-potential-like branch asymmetries arise naturally from non-relativistic propagation effects.
Versions
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BibTeX
@misc{ferreira2026nonrelativistic,
title = {{Non-relativistic Cosmological Collider Signals}},
author = {Matheus C. Ferreira and Felipe T. Falciano},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.20102},
eprint = {2605.20102},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.20102},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Non-relativistic Cosmological Collider Signals
AU - Matheus C. Ferreira
AU - Felipe T. Falciano
PY - 2026
DA - 2026/09/13
PB - arXiv
DO - 10.48550/arxiv.2605.20102
UR - https://arxiv.org/abs/2605.20102
AB - We investigate a non-relativistic realization of the boostless cosmological collider in a scenario where inflationary interactions are mediated by a massive tilted-ghost spectator field. Unlike standard boostless collider constructions, in which the characteristic non-Gaussian signatures are mainly generated by boost-breaking interaction vertices, the dominant effect in the present framework arises directly from the propagation of the spectator modes. Non-relativistic corrections deform the bulk mode functions, inducing a tilt that modifies the in-in correlators and generates a distinctive collider signal. The resulting squeezed-limit non-Gaussianity reproduces the qualitative structure of boostless cosmological-collider signals while originating from a fundamentally different dynamical mechanism. A central feature of the construction is the emergence of an effective chemical-potential-like parameter that controls the relative weight of the two late-time oscillatory branches. However, the tilted-ghost mode exhibits distinctive dynamical features and does not correspond to a conventional chemical-potential deformation. Depending on the sign of the tilt, the corresponding non-Gaussian signal can be either enhanced or suppressed. We show that the tilted-ghost scenario provides a simple effective framework in which boostless-collider phenomenology and chemical-potential-like branch asymmetries arise naturally from non-relativistic propagation effects.
ER -