Issai Schur: Ramsey theory before Ramsey.

*(English)*Zbl 0845.01018The article sketches the life of the famous German algebraist, Issai Schur (1875-1941), until his dismissal from the University of Berlin by the racist laws of the Nazis in 1935. The paper then tries to solve the ‘mystery’, raised by L. Mirsky, why Schur never returned to combinatorics which he had entered via his classic lemma on partitions of integers in 1916, “which gave birth (in the opinion of the author) ... to a new direction in mathematics; now called Ramsey Theory.” The author solves it in the negative sense by giving strong evidence, that Schur, in fact, did retain his interest in that part of combinatorics. As Schur’s student, Alfred Brauer, had pointed out before, it was probably Schur who created the conjecture, usually attributed to the Dutch P. J. H. Baudet (1891-1921), and proven by B. L. van der Waerden in 1926. The author supports Brauers assertion, partly using biographical material on Baudet which was provided to him by the Dutch historian of mathematics, Gerard Alberts. The question whether Baudet created the conjecture independently remains open.

Reviewer: R.Siegmund-Schultze (Berlin)

##### MSC:

01A70 | Biographies, obituaries, personalia, bibliographies |

01A60 | History of mathematics in the 20th century |