Why Is India Building A Gravitational Wave Detector?

Key takeaways

LIGO's discovery of gravitational waves confirmed Einstein's theories and earned a Nobel Prize in 2017.
India is establishing its own gravitational wave detector, IndiGO, in collaboration with LIGO.
IndiGO involves prominent Indian institutions, enhancing global gravitational wave detection efforts.
The Michelson Interferometer, known for its extreme sensitivity, will be the core instrument for IndiGO.

The great discovery of gravitational waves was by LIGO of Livingston and Hanford detectors, which also won the 2017 nobel prize, which included Karan Jani, a LIGO scientist of Indian origin. It can be called the most remarkable discoveries of today’s time, confirming Einstein’s idea of their existence. India is also on its mission to built such a highly sensitive interferometry to detect gravitational waves and is already on its way to build one.

IndiGO - Built In Collaboration With LIGO

IndiGO is an international collaboration between the LIGO Laboratory and three lead institutions in the IndIGO consortium: Institute of Plasma Research (IPR) Gandhinagar, Inter University Centre for Astronomy and Astrophysics (IUCAA), Pune and Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. The institute will add to an already established network of the LIGO detectors.

Understanding the Instrument

When even a few molecules bounce off of LIGO's mirrors, it could induce vibrations that could mask a gravitational wave signal. Therefore,for the detectors to detect these waves, they have to be extremely sensitive. What better option than the michelson Interferometer, which are the most sensitive devices to be ever built? The instrument invented by the American physicist Albert Michelson in the 1880’s has a number of applications today and the gravitational wave detection is one of them. [caption id="attachment_10000799" align="alignnone" width="500"]

Basic configuration of a Michelson Interferometer.[/caption] IndiGO will have the interferometer with Fabry-Perot enhanced arms of 4 km length. The motive of the setup is to detect differential changes in the arm-lengths as small as 10-23 Hz-1/2 in the frequency range between 30 to 800 Hz. The design would be identical to that of Advanced LIGO detectors that are being commissioned in the US.

Why We Need To Detect GW At All?

The first plot shows the combined antenna-pattern functions (a measure of the sensitivity of the network) of a network consisting of two LIGO detectors in Hanford, one LIGO in Livingston and the Virgo detector in Italy (HHLV). The second plot shows the same for a network consisting of one LIGO detector in Hanford, LIGO Livingston, Virgo and LIGO-India (HLVI). Redder regions correspond to regions of higher sensitivity and bluer regions to regions of poorer sensitivity. Locations of the detectors (LIGO-Hanford, LIGO-Livingston, Virgo, LIGO-India, KAGRA) are marked by filled black circles. The scientific benefits of LIGO-India are enormous. Adding a new detector to the existing network will increase the expected event rates. By adding a new detector in the network, the sensitivity, sky coverage and the duty cycle will automatically be increased and will therefore boost the detection confidence of new gravitational wave sources. The improvement from LIGO-India would come in the ability of localizing these sources in the sky. It was important to add this new detector in Aundh in Hingoli district of Maharashtra, so that it is geographically well-separated for the rest of the detectors, thereby improving the source-location accuracies dramatically, by about 5-10 times, thus enabling us to use GW observations as an excellent astronomical tool.

Impact Of IndiGO On Indian Research

Research: There is currently no research in gravitational wave in India based on Indian instrument. The development of this LIGO-India project will open many opportunities for the coming generation of scientists to do research in the field. It will bring together scientists and engineers from different fields like optics, lasers, gravitational physics, astronomy and astrophysics, cosmology, computational science, mathematics and various branches of engineering. In order to fully realize the potential of multi-messenger astronomy, the LIGO-India project will join forces with several Indian astronomy projects. Potential collaborators include the Astrosat project, future upgrades of the India-based Neutrino Observatory and optical/radio telescopes. Industry: LIGO project has facilitated major industry-academic research partnerships in USA and Europe, and has produced several important technological spin offs . LIGO-India will provide similar opportunities to Indian industry. This new project to be completed by 2025 will certainly bring many research opportunities in the country that were never open before and the setup will allow us to contribute to groundbreaking discoveries, in partnership with the other LIGO collaborators.

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