# A Cosmological Higgs Collider

## TL;DR

This paper proposes the Cosmological Higgs Collider (CHC), a method to probe Higgs interactions at high energies through primordial non-Gaussianities generated during inflation, focusing on Higgs-modulated reheating and its observable signatures.

## Contribution

It introduces the CHC concept, modeling Higgs-inflaton interactions and calculating observable signals in the bispectrum, extending collider ideas to cosmological scales.

## Key findings

- CHC signals can produce large imprints in the squeezed bispectrum.
- Higgs interactions during inflation can be probed via primordial non-Gaussianities.
- The model demonstrates how Higgs fluctuations influence reheating and observable cosmological signatures.

## Abstract

The quantum fluctuations of the Higgs field during inflation could be a source of primordial density perturbations through Higgs-dependent inflaton decay. By measuring primordial non-Gaussianities, this so-called Higgs-modulated reheating scenario provides us a unique chance to probe Higgs interactions at extremely high energy scale, which we call the Cosmological Higgs Collider (CHC). We realize CHC in a simple scenario where the inflaton decays into Higgs-portal scalars, taking account of the decay of the Higgs fluctuation amplitude after inflation. We also calculate the CHC signals of Standard Model particles, namely their imprints in the squeezed bispectrum, which can be naturally large. The concept of CHC can be straightforwardly generalized to cosmological isocurvature colliders with other types of isocurvature perturbations.