The science case for LIGO-India
The global network of gravitational-wave detectors has completed three observing runs with ∼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. Such additions to the network increase the number of baselines and the network SNR of GW events. These enhancements help improve the sky-localization of those 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 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.
© 2021 IOP Publishing Ltd. Received 9 June 2021; Revised 3 October 2021; Accepted 19 November 2021; Published 15 December 2021. We would like to thank our colleagues in the LIGO-India Scientific Collaboration and the LIGO-India Project for valuable inputs. We appreciate the several discussions we had with members of the various working groups in the LIGO-Virgo-KAGRA collaborations. In particular, we thank KG Arun, Bala Iyer, Shivaraj Kandhasamy, Jose Matthew, Fred Raab, Rory Smith, and Tarun Souradeep for valuable discussions and inputs. This work makes use of NumPy , SciPy , Matplotlib , AstroPy [156, 157], jupyter , dynesty , bilby  and PESummary  software packages. Thanks are also due to the Department of Science and Technology (DST) and the Department of Atomic Energy (DAE) of India. Specifically, MS acknowledges the support from the Infosys Foundation, the Swarnajayanti fellowship Grant DST/SJF/PSA-01/2017–18, and the support from the National Science Foundation with Grants PHY-1806630 and PHY-2010970, AP acknowledges support from the DST-SERB Matrics Grant MTR/2019/001096 and SERB-Power-fellowship Grant SPF/2021/000036, DST, India. AM acknowledges support from the DST-SERB Start-up Research Grant SRG/2020/001290, and PA, AV, and SG acknowledge support from DAE under Project No. RTI4001. PA's research was also supported by the Max Planck Society through a Max Planck Partner Group at ICTS-TIFR and by the Canadian Institute for Advanced Research through the CIFAR Azrieli Global Scholars program. SS is supported by an Eberly postdoctoral fellowship at Pennsylvania State University and BSS is supported by NSF Grants PHYS-1836779, PHYS-2012083 and AST-2006384. Thanks are due to computational support provided by the Alice (ICTS-TIFR) and Sarathi (IUCAA) clusters and computing resources in SINP. In addition, the authors are also grateful for the computational resources provided by LIGO Laboratory and Leonard E Parker Center for Gravitation, Cosmology and Astrophysics at the University of Wisconsin-Milwaukee and supported by National Science Foundation Grants PHY-0757058, PHY-0823459, PHY-1626190 and PHY-1700765. This paper has been assigned the internal LIGO Preprint Number P2100073. Data availability statement: The data that support the findings of this study are available upon reasonable request from the authors.
Accepted Version - 2105.01716.pdf