Felix Issidorowitsch Frankl (12 March 1905, Vienna – 7 Aprile 1961, Nalchik Russian: Феликс Исидорович Франкль) was an Austrian mathematician, who went to live in the Soviet Union where he had an academic career as a university professor.[1]
He studied topology at the Faculty of Mathematics of the University of Vienna under Hans Hahn, gaining his doctorate in 1927.[2]
Frankl went to live in the Soviet Union in 1929. Here he initially collaborated with Lev Pontryagin in topology (they a paper co-authored a paper published in 1930 in the Mathematische Annalen. His interests then shifted to certain particular differential equations which are important for high-speed aerodynamics. These differential equations were of mixed elliptic-hyperbolic type. They determined the transition in aerodynamics between transonic and supersonic speeds.
He attended the First International Topological Conference held in Moscow in 1935.[3] In 1957 he was awarded the Leonhard Euler Gold Medal of the Russian Academy of Sciences.[1]