Kerékjártó in 1923.
Princeton University Princeton, New Jersey, United States
Kerékjártó at Princeton, 1924.
Kerékjártó in Szeged, June 1928.
Kerékjártó at Lillafüred, 1934.
Kerékjártó with Paul Valéry, 1936.
Kerékjártó in 1937.
Kerékjártó with J Piaget, 1938.
Corvinus University of Budapest, Budapest, Hungary
Kerékjártó studied at Corvinus University of Budapest, and after only five semesters he was granted permission to submit his doctoral thesis. He earned his Ph.D. in 1920.
Hungarian Academy of Sciences, Budapest, Hungary
Kerékjártó was a corresponding member of the Hungarian Academy of Sciences from 1934 and a full member from 1945.
Kerékjártó studied at the Corvinus University of Budapest, and after only five semesters he was granted permission to submit his doctoral thesis. He earned his Ph.D. in 1920.
Kerékjártó became a privatdocent at Szeged University in 1922, an extraordinary professor in 1925, and professor Ordinarius in 1929. In 1938 he became professor Ordinarius at Budapest University. From 1922 to 1926 he had also traveled abroad: in 1922-1923 he stayed at Göttingen University where he gave lectures on topology and mathematical cosmology; in 1923 he taught geometry and function theory at the University of Barcelona; and from 1923 to 1925 he was at Princeton University, where he lectured on topology and continuous groups. When he returned to Europe he lectured in Paris. In 1938 he returned to Budapest to teach at Eötvös Loránd University.
After Max Dehn and P. Heegaard’s article “Analysis situs” (1907), in Encyklopädie der mathematischen Wissenschaften and Schönflies’ Die Entwicklung der Lehre von den Puktmannigfaltigkeiten (1908), the first three monographs on topology to appear were Veblen’s “Analysis situs,” in American Mathematical Society Colloquium Publications (1922), Kerékjártó's (1923), and S. Lefschetz’s “L’analysis situs et la géométrie algébrique” (1924). Kerékjártó's probably sold best and was the most widely known, but it has exerted much less (if any) influence than the two others.
Kerékjártó's papers written around 1940 make a more favorable impression. In general, they are correct. They deal with his earlier problems on topological groups but use methods which in the meantime had become obsolete. It is quite probable that he did not know the developments in topology after 1923. The strangest feature is that he never used set-theory symbols, such as the signs for belonging to a set, inclusion, union, and intersection. Apparently, he did not know of their existence.
Kerékjártó mainly continued the work of Brouwer and Hilbert on mappings of surfaces and topological groups acting upon surfaces. The undeniable merits of his work are obscured by the manner of presentation. The classification of open surfaces is usually ascribed to Kerékjártó, but the exposition of this subject in his book hardly justifies this claim. It was probably his greatest accomplishment that he became interested in groups of locally equicontinuous mappings (of a surface), although his definition of this notion did not match the way in which it was applied; strangely enough, he did not notice that this notion had already been fundamental in Hilbert’s work. The best result in studying such groups with Kerékjártó's methods has recently been achieved by I. Fary, who proved that equicontinuous, orientation-preserving groups of the plane are essentially subgroups of the Euclidean or of the hyperbolic group.
In addition to the work on topology in German and a work on foundations of geometry in Hungarian, which has been translated into French, Kerékjártó wrote some sixty papers, most of them comprising only a few pages.
Kerékjártó was a corresponding member of the Hungarian Academy of Sciences from 1934 and a full member from 1945. He was also a member of several foreign mathematical societies.
Kerékjártó was married and had a son and, supposedly, a daughter.