# Stochastic Gravitational Waves from Inflaton Decays

## TL;DR

This paper investigates the generation of stochastic gravitational waves during inflaton decay into vector particles, predicting high-frequency spectra that challenge current detection capabilities and suggesting the need for advanced high-frequency GW detectors.

## Contribution

It introduces the analysis of gravitational wave production from inflaton decays into vector particles, extending previous models focused on scalar and fermion decay products.

## Key findings

- GW spectra are too high in frequency for current detectors.
- Decays into vector particles produce distinct GW frequency spectra.
- High-frequency GW detection requires new experimental designs.

## Abstract

Due to the universality of gravitational interactions, it is generally expected that a stochastic gravitational wave (GW) background could form during the reheating period when the inflaton perturbatively decays with the emission of gravitons. Previously, only models in which the inflaton dominantly decays into a pair of light scalar and/or fermion particles were considered in the literature. In the present paper, we focus on the cases with a vector particle pair in the final decay product. The differential decay rates for the three-body gravitational inflaton decays are presented for two typical couplings between the inflaton and vector fields, from which we predict their respective GW frequency spectra. It turns out that, similar to the scalar and fermion cases, the obtained GW spectra is too high in frequency to be observed by the current and near-future GW detection experiments and calls for a new design of high-frequency GW detectors.