Gustav Roch

Gustav Roch (1839 to 1866) was a German mathematician best remembered for the Riemann-Roch theorem, which links the topological genus of a Riemann surface to purely algebraic properties of that surface. He began at the Polytechnic Institute in Dresden, where his father expected him to train as a chemist, but his teacher Oscar Schlömilch recognised his gift for mathematics and mathematical physics and steered him away from chemistry. While still a student he was already publishing work on the mathematical theory of electricity and magnetism. He went on to study at Leipzig, Göttingen, where he attended lectures by Bernhard Riemann, and Berlin, and took his doctorate at Leipzig in 1862. After a habilitation at Halle he published, in Crelle's Journal, the paper on the number of arbitrary constants in algebraic functions that contains the theorem now bearing his name; Max Noether and Alexander von Brill later gave it the name Riemann-Roch and refined it. Roch was appointed extraordinary professor at Halle in August 1866, but ill health sent him to Venice, where he died of tuberculosis in November 1866 at the age of 26, only a few months after Riemann himself.