About Ivan Petrovsky
Ivan Georgiyevich Petrovsky (Russian: Иван Георгиевич Петровский; 18 January 1901 – 15 January 1973) was a Soviet mathematician working mainly in the field of partial differential equations. He greatly contributed to the solution of Hilbert's 19th and 16th problems, and discovered what are now called Petrovsky lacunas. He also worked on the theories of boundary value problems, probability, and on the topology of algebraic curves and surfaces. He was a member of the Academy of Sciences of the Soviet Union since 1946 and was awarded Hero of Socialist Labour in 1969. A. (2001), "Ivan Georgievich Petrovskii", in Osipov, Yu.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.