Harry Ernest Rauch (November 9, 1925 – June 18, 1979) was an American mathematician, who worked on complex analysis and differential geometry.
He was born in Trenton, New Jersey, and died in White Plains, New York.
Rauch earned his PhD in 1948 from Princeton University under Salomon Bochner with thesis Generalizations of Some Classic Theorems to the Case of Functions of Several Variables.
His research was on differential geometry (especially geodesics on n-dimensional manifolds), Riemann surfaces, and theta functions.
In the early 1950s Rauch made fundamental progress on the quarter-pinched sphere conjecture in differential geometry.