Probing for massive stochastic gravitational-wave background with a detector network

TL;DR

This paper extends correlation analysis methods to detect a massive stochastic gravitational-wave background, demonstrating that a network of ground-based detectors can identify additional polarization modes and measure graviton mass around 10^{-14} eV.

Contribution

It introduces a framework for probing massive gravitational waves and polarization modes using detector networks, enabling model-independent tests of gravity theories.

Findings

A detector network can detect massive stochastic gravitational waves with mass ~10^{-14} eV.

More than three detectors can separate polarization modes and determine graviton mass.

The method extends previous correlation analysis to include massive gravity scenarios.

Abstract

In a general metric theory of gravitation in four dimensions, six polarizations of a gravitational wave are allowed: two scalar and two vector modes, in addition to two tensor modes in general relativity. Such additional polarization modes appear due to additional degrees of freedom in modified gravity theories. Also graviton mass, which could be different in each polarization, is another characteristic of modification of gravity. Thus, testing the existence of additional polarization modes and graviton mass can be a model-independent test of gravity theories. Here we extend the previous framework of correlation analysis of a gravitational-wave background to the massive case and show that a ground-based detector network can probe for massive stochastic gravitational waves with its mass around ~10^{-14} eV. We also show that more than three detectors can cleanly separate the mixture of polarization modes in detector outputs and determine the graviton mass.