In the 1970s, Starobinsky worked on the theory of particle creation in the early universe and particle generation and radiation from rotating black holes (1973/74), a precursor of the theory of Hawking radiation. He was also, in 1979, a pioneer in the theory of cosmic inflation in the Russian scientific literature. The phase of inflation postulates that the universe size grew quadrillion times faster that the speed of light.[1] Starobinsky worked on Starobinsky inflation, a modification to general relativity which attempts to explain inflation. In the American and western European physics literature, Alan Guth was considered a pioneer of the theory during the same time period.