India has given the green light for the construction of LIGO-India, a replica of the twin Laser Interferometer Gravitational-Wave Observatory (LIGO) facilities that made the first direct detection of gravitational waves in 2015. The new facility will be located in Maharashtra, and it is expected to be operational by the end of the decade. LIGO-India will cost around $320 million, with funding coming from India’s Raja Ramanna Center for Advanced Technology, Institute for Plasma Research, Inter-University Centre for Astronomy and Astrophysics, and the Department of Atomic Energy Directorate of Construction Services and Estate Management, as well as the LIGO Laboratory, which is operated by Caltech and MIT and funded by the National Science Foundation.
The facility will include an L-shaped interferometer with 4-kilometer-long arms and will join a global network of gravitational-wave observatories, including Virgo in Italy and KAGRA in Japan. With its advanced gravitational-wave-sensing technology, LIGO-India will greatly improve the ability of scientists to pinpoint the sky locations of the sources of gravitational waves. It will also fill in blind spots in the current gravitational-wave network.
The LIGO team, in collaboration with Indian scientists, has developed the latest and best techniques that will be incorporated from the beginning at LIGO-India. The new observatory will increase the precision with which scientists can localize gravitational-wave events by an order of magnitude, greatly enhancing our ability to answer fundamental questions about the universe, including how black holes form, the expansion rate of our universe, and to more rigorously test Einstein's general theory of relativity.
LIGO-India will make it easier to spot multi-messenger events, where light and gravitational waves are the messengers. The observatory should also enable researchers around the world to combine observations from optical and radio telescopes with the information from the gravitational-wave network to make new discoveries about the universe.
The international collaboration has already resulted in an exchange of ideas and new relationships between India and the LIGO team. For instance, dozens of Indian students have been chosen to work with the LIGO team as part of Caltech's Summer Undergraduate Research Fellowship (SURF) program. In addition, Caltech plans to invite several visiting scientists from India to work on LIGO at Caltech.