English

Missing Scalars at the Cosmological Collider

High Energy Physics - Phenomenology 2022-02-07 v2 Cosmology and Nongalactic Astrophysics

Abstract

Light scalar fields typically develop spatially varying backgrounds during inflation. Very often they do not directly affect the density perturbations, but interact with other fields that do leave nontrivial signals in primordial perturbations. In this sense they become "missing scalars" at the cosmological collider. We study potentially observable signals of these missing scalars, focusing on a special example where a missing scalar distorts the usual oscillatory features in the squeezed bispectrum. The distortion is also a useful signal distinguishing the de Sitter background induced thermal mass from a constant intrinsic mass.

Keywords

Cite

@article{arxiv.2108.11385,
  title  = {Missing Scalars at the Cosmological Collider},
  author = {Qianshu Lu and Matthew Reece and Zhong-Zhi Xianyu},
  journal= {arXiv preprint arXiv:2108.11385},
  year   = {2022}
}

Comments

20 pages, 3 figures, v2: improved discussion, as published in JHEP

R2 v1 2026-06-24T05:25:07.509Z