Jayant Vishnu Narlikar (born 19 July 1938) is an Indian astrophysicist and emeritus professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA).[1] He developed with Sir Fred Hoyle the conformal gravity theory, known as Hoyle–Narlikar theory. It synthesises Albert Einstein's theory of relativity and Mach's principle. It proposes that the inertial mass of a particle is a function of the masses of all other particles, multiplied by a coupling constant, which is a function of cosmic epoch.