STFC Capacity Building with LIGO-India With the first direct observation of gravitational waves from coalescing black holes and neutron stars by the LIGO/VIRGO Scientific collaborations (2015-present) there has been great interest around the world in extending the reach of the future detector network, as gravitational wave astronomy breaks open a new window on the Universe. Indeed with the detection of a gravitational and electromagnetic signature from GW170817, a binary neutron start inspiral, the era of multi-messenger astronomy is truly here.  With the siting of the 3rd aLIGO detector in India there is an essential need for critically skilled students, postdocs and early career researchers to be trained at the highest level in gravitational wave astronomy, for construction of the infrastructure & technology, development of high performance computing/machine learning algorithms and efficient data pipelines. In turn, the LIGO India project will help Indian scientific community to be a major player in the emerging research frontier of GW astronomy. Based on the model of the LIGO Scientific Collaboration, there is a huge potential for inclusive growth across many areas of industry, academia and society. The UK consortia also have a strong track record of outreach & public engagement, which will be shared with our Indian collaborators.   The Indian partners will be those institutions jointly coordinating and executing the LIGO-India project and their associates: the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, the Indian Institute for Science Education & Research (IISER) and the TIFR Center for Interdisciplinary Sciences, Hyderabad. Over the coarse of the project we will also develop linkages with the Department of Atomic Energy organisations: Institute for Plasma Research (IPR), Gandhinagar and the Raja Ramanna Centre for Advanced Technology (RRCAT), Indore who will be leading the development of infrastructure (laser, vacuumm system, suspensions and seismic isolation).  The main objectives of this proposal are to build up technical capacity and capability in India in a broad range of multidisciplinary fields associated with gravitational wave detection. This field is very wide in nature and the technologies required range from delicate mechanical instrumentation, through high and low power laser optics to signal processing and large data handling, and thus capacity built up from the work of this proposal will have wide application in other fields. We have already identified several UK-India comapny linkages in the areas of machine learning, sensors & autonomous systems & data algorithms, and we propose to share our experience of methods to spin-out high technology research into applied fields.  The consortium behind this proposal in the UK - the Universities of the West of Scotland, Glasgow, Cardiff, Birmingham, Southampton, and Sheffield - has a strong and extensive track record in detector development, data analysis and background theory and astrophysics for the gravitational wave field, as well as working with industry, in public outreach and school teacher CPD. Thus it is ideally suited to provide training for PhD students, research assistants and early career researchers in the ODA country of India to build capacity and make these countries major contributors to the international community and to provide dedicated summer schools/workshops in the UK utilising the expansive UK training network, for training the incoming members from the ODA countries in the necessary data analysis and experimental hardware techniques. Further the consortium will arrange opportunities for researchers to travel to/from India and the UK to capacity build and perform on-site training of researchers. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.