Cosmological collider signals of modular spontaneous CP breaking
High Energy Physics - Phenomenology
2026-04-08 v1 Cosmology and Nongalactic Astrophysics
High Energy Physics - Theory
Abstract
We consider a modular-invariant extension of the Standard Model. Assuming that the modulus is the inflaton, the CP-violating phases of the Yukawa couplings evolve during inflation. This dynamics favours a Higgs condensate, so that Standard Model fermions mediate a one-loop cosmological collider signal enhanced by chemical potentials. Next-generation experiments can probe sub-Planckian values of the modulus decay constant. We provide precise expressions for Dirac fermions with chemical potentials in de Sitter.
Cite
@article{arxiv.2604.05548,
title = {Cosmological collider signals of modular spontaneous CP breaking},
author = {Shuntaro Aoki and Alessandro Strumia},
journal= {arXiv preprint arXiv:2604.05548},
year = {2026}
}
Comments
19 pages, 3 figures. Webinar presentation: https://youtu.be/ToUNLzRl8Pc