The Science Case for LIGO-India

TL;DR

Expanding the global gravitational-wave detector network with LIGO-India will significantly enhance detection rates, sky localization, and the precision of source property measurements, advancing astrophysics and fundamental physics tests.

Contribution

This paper quantifies the improvements in detection capabilities and source characterization resulting from adding LIGO-India to the existing gravitational-wave detector network.

Findings

Improved sky localization of GW events.

Enhanced detection rates and survey completeness.

Better constraints on fundamental physics tests.

Abstract

The global network of gravitational-wave detectors has completed three observing runs with $\sim 50$ detections of merging compact binaries. A third LIGO detector, with comparable astrophysical reach, is to be built in India (LIGO-Aundha) and expected to be operational during the latter part of this decade. Multiple detectors operating at different parts of the globe will provide several pairs of interferometers with longer baselines and an increased network SNR. This will improve the sky localisation of GW events. Multiple detectors simultaneously in operation will also increase the baseline duty factor, thereby, leading to an improvement in the detection rates and, hence, the completeness of surveys. In this paper, we quantify the improvements due to the expansion of the LIGO Global Network (LGN) in the precision with which source properties will be measured. We also present examples of how this expansion will give a boost to tests of fundamental physics.