Testing the arrow of time at the cosmo collider
Abstract
Abstract Normal particles carry a microscopic arrow of causality. Lee-Wick ghosts carry the reversed arrow, mediating characteristic collider signals in flat space: opposite-sign scattering amplitudes that violate positivity bounds; acausality on time scales set by their negative decay rate. During inflation, the corresponding cosmo-collider ghost signals are: opposite-sign non-Gaussianities; Boltzmann-unsuppressed local oscillatory signals without their non-local counterparts; IR-enhanced bi-spectrum and power spectrum, depending on the dimension of the interaction operator, which decreases if the ghost decay rate is comparable to the Hubble rate.
Fields of Study & Subjects
Cosmology and Gravitation Theories
Dark Matter and Cosmic Phenomena
Particle physics theoretical and experimental studies
Publication details
- Journal / source
- Journal of Cosmology and Astroparticle Physics
- Publisher
- IOP Publishing
- Volume
- 2026
- Issue
- 03
- Pages
- 067–067
- Publication date
- 1 March 2026