General Estimate for the Graviton Lifetime

TL;DR

This paper derives a general formula for the graviton's lifetime based on kinematic principles and estimates it using quantum gravity data, suggesting gravitons may have a very short lifetime.

Contribution

It introduces a general estimate for graviton lifetime and applies non-perturbative quantum gravity results to evaluate its magnitude.

Findings

Graviton lifetime depends on energy and fundamental constants.

Short graviton lifetime cannot be ruled out based on current estimates.

The formula involves a series expansion in the product of the cosmological constant and Newton's constant.

Abstract

By means of general kinematical arguments, the lifetime $\tau$ of a graviton of energy $E$ for decay into gravitons is found to have the form $\tau^{-1} = \frac{1}{EG} \sum_{j=1,2,...} c_j (\Lambda G)^j$. Some recent, preliminary results of non perturbative simplicial quantum gravity are then employed to estimate the effective values of $G$ and $\Lambda G$. It turns out that a short lifetime of the graviton cannot be excluded.