Maria Hasse

Maria-Viktoria Hasse (May 30, 1921 – January 10, 2014) was a German mathematician who became the first female professor in the faculty of mathematics and science at TU Dresden.^[1] She wrote books on set theory and category theory,^[2] and is known as one of the namesakes of the Gallai–Hasse–Roy–Vitaver theorem in graph coloring.

Hasse was born in Warnemünde. She went to the Gymnasium in Rostock, and after a term in the Reich Labour Service from 1939 to 1940, studied mathematics, physics, and philosophy at the University of Rostock and University of Tübingen from 1940 to 1943, earning a diploma in 1943 from Rostock. She continued at Rostock as an assistant and lecturer, earning a doctorate (Dr. rer. nat.) in 1949 and a habilitation in 1954.^[2][1] Her doctoral dissertation, Über eine singuläre Intergralgleichung 1. Art mit logarithmischer Unstetigkeit [On a singular integral equation of the 1st kind with logarithmic discontinuity], was supervised by Hans Schubert;^[3] her habilitation thesis was Über eine Hillsche Differentialgleichung [On Hill's differential equation]. She worked as a professor of algebra at TU Dresden from 1954 until her 1981 retirement.^[4]

With Lothar Michler, Hasse wrote Theorie der Kategorien [Category Theory] (Deutscher Verlag, 1966).^[5] She also wrote Grundbegriffe der Mengenlehre und Logik [Basic Concepts of Set Theory and Logic] (Harri Deutsch, 1968).^[6]

In the theory of graph coloring, the Gallai–Hasse–Roy–Vitaver theorem provides a duality between colorings of the vertices of a graph and orientations of its edges. It states that the minimum number of colors needed in a coloring equals the number of vertices in a longest path, in an orientation chosen to minimize the length of this path. It was stated in 1958 in a graph theory textbook by Claude Berge, and independently published by Hasse, Tibor Gallai, B. Roy, and L. Vitaver. Hasse's publication of this result was the second chronologically, in 1965.^[7]