Washington DC, Mar 31 (ANI): India on Thursday signed a memorandum of understanding (MoU) for building a state-of-the-art Laser Interferometer Gravitational-wave Observatory (LIGO) project with the United States. The MoU was signed in presence Prime Minister Narendra Modi, who also met the scientists from LIGO. The MoU has been signed between the National Science Foundation (NSF) of the US and India's Department of Atomic Energy (DAE) and Department of Science and Technology (DST). PM Modi greeted the scientists from LIGO, who proved gravitational waves theory.