Comparison of global networks of third-generation gravitational-wave detectors

TL;DR

This paper compares different configurations of third-generation gravitational-wave detector networks worldwide, evaluating their performance and potential as intermediate steps toward a full global network.

Contribution

It provides a comparative analysis of various European and international third-generation GW detector configurations and their performance in a global network.

Findings

A single L-shaped underground detector with CE-40km outperforms a 10km triangle in an international network.

A 2L+CE network offers a promising intermediate step toward a full 2L+CE global network.

Networks including LIGO-India show very interesting performance capabilities.

Abstract

We study the performances of a world-wide network made by a European third-generation gravitational-wave (GW) detector, together with a 40km Cosmic Explorer detector in the US, considering three scenarios for the European detector: (1) Einstein Telescope (ET) in its 10km triangle configuration; (2) ET in its configuration featuring two 15km L-shaped detectors in different sites, still taken to have all other ET characteristics (underground, and with each detector made of a high-frequency interferometer and a cryogenic low-frequency interferometer); (3) A single L-shaped underground interferometer with the ET sensitivity curve, either with 15km or with 20km arm length. Overall, we find that, if a configuration with two widely separated L-shaped detectors ("2L") should be retained for ET, the network made by a single-L European underground detector together with CE-40km could already provide a very interesting intermediate step toward the construction of a full 2L+CE network, and is in any case superior to a 10km triangle not inserted in an international network. We also study the performance of a network made by a single L-shaped underground interferometer with the ET sensitivity curve together with a single 40km CE and with LIGO-India (taken at A# sensitivity), and we find that it also has very interesting performances.