Hans Petersson

Hans Petersson was a German mathematician, known for his research on modular and automorphic forms. He introduced the Petersson [inner product] and is also known for the Ramanujan–Petersson conjecture.
He received his doctorate in 1925 from the University of Hamburg. His thesis advisor was Erich Hecke.
In a series of papers, Petersson used the Poincaré [series |Poincaré series] to give a complete construction of all meromorphic functions and differentials on a compact Riemann surface.