Subrahmanyan Chandrasekhar, an Indian-American astrophysicist, made seminal contributions to the study of black holes and gravitational waves. His work on the Chandrasekhar limit, which determines the critical mass above which a white dwarf collapses into a neutron star or black hole, earned him the Nobel Prize in Physics in 1983.

Theoretical astrophysics in India encompasses a wide range of research areas, including cosmology and the origin of the universe, stellar evolution and nucleosynthesis, black hole physics and gravitational waves, and more. Indian scientists have made significant contributions to each of these fields.

Jayant V. Narlikar, an Indian astrophysicist and cosmologist, has made significant contributions to the study of the formation and evolution of galaxies. He proposed the Hoyle-Narlikar theory of gravity, which challenges the conventional theory of general relativity.

The Tata Institute of Fundamental Research (TIFR) in Mumbai, India, is a premier research institute dedicated to theoretical astrophysics and other fundamental sciences. It has played a significant role in advancing theoretical astrophysics research in India.

R. K. Manchanda, an Indian astrophysicist, is known for his work on the cosmic microwave background radiation (CMB). He was involved in the analysis of CMB data from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite, which provided valuable insights into the early universe.

Astrosat is an Indian satellite mission dedicated to studying black holes, neutron stars, and other compact objects in the universe. It carries a suite of instruments designed to observe X-rays, ultraviolet, and optical light from these objects.

T. Padmanabhan, an Indian astrophysicist, is known for his work on the theory of quantum gravity. He has proposed several theories, including loop quantum gravity and entropic gravity, which attempt to unify general relativity and quantum mechanics.

The Indian Journal of Astrophysics (IJA) is a peer-reviewed scientific journal that publishes original research in all areas of astrophysics. It is published by the Indian Academy of Sciences and is one of the leading astrophysics journals in India.

D. K. Biswas, an Indian astrophysicist, is known for his work on the evolution of massive stars. He has studied the late stages of stellar evolution, including supernovae and the formation of neutron stars and black holes.

The Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, India, has made significant contributions to the study of gravitational waves. It is home to the Laser Interferometer Gravitational-Wave Observatory (LIGO) India project, which aims to build a gravitational wave detector in India.

Sandip K. Chakrabarti, an Indian astrophysicist, is known for his work on the physics of accretion disks around black holes. He has studied the behavior of matter in these disks and the processes that lead to the emission of high-energy radiation.

PRISM (Polarisation-based Remote Imaging and Spectro-polarimetry Mission) is an Indian satellite mission designed to study the cosmic microwave background radiation. It aims to measure the polarization of the CMB, which can provide valuable insights into the early universe.

Rashmi Sharma, an Indian astrophysicist, is known for her work on the formation of the first stars in the universe. She has studied the conditions necessary for the formation of these stars and the role they played in the early evolution of the universe.

The Tata Institute of Fundamental Research (TIFR) in Mumbai, India, has made significant contributions to the study of dark matter. Its researchers have conducted extensive studies on the properties of dark matter and its role in the formation and evolution of galaxies.

Pankaj Jain, an Indian astrophysicist, is known for his work on the theory of inflation in the early universe. He has studied the conditions necessary for inflation to occur and the implications of inflation for the evolution of the universe.