István Fáry

István Fáry

István Fáry (born June 30, 1922 in Gyula , † November 2, 1984 in El Cerrito , California ) was a native of Hungary , American mathematician and university professor .

Life and career

The information on the life of István Fáry is sparse. He began studying at the Eötvös Loránd University in Budapest in 1940 and obtained his doctorate in 1948 from the University of Szeged . In the same year he moved to the Center national de la recherche scientifique in Paris . There he achieved the degree of Docteur ès sciences in 1953 under the guidance of Jean Leray . Then he went to the University of Montreal . From 1957 to 1971 he worked at the University of California at Berkeley , where he became full professor in 1962 .

Fáry married his wife Therese while in Montreal and had a daughter named Kataline.

Scientific work

István Fáry worked in geometry on algebraic geometry , differential geometry and the geometry of convex bodies , in topology on algebraic topology and knot theory and also on combinatorics and graph theory . He was the author or co-author of more than 40 scientific publications .

So he proved - independently of Klaus Wagner - the important theorem of Wagner and Fáry for the four-color problem .

He also received a lot of recognition with a result presented in 1949, which was found again in 1950 by John Milnor and is therefore mostly known today as the Fáry and Milnor theorem ( English Fáry-Milnor theorem ). It says:

In every closed twofold continuously differentiable space curve , which is knotted in the sense of the knot theory, has at least the total curvature . ${\displaystyle {\mathbb {R} }^{3}}$ ${\displaystyle 4\pi }$

Web links

• Web link to "A Panorama of Hungarian Mathematics in the Twentieth Century, I"
• List of Fáry's works on MathSciNet
• Entry in "The Mathematics Genealogy Project"
• Statement by the University of California in memory of István Fáry (1985)

References and footnotes

1. ↑ Some dates are uncertain. There are discrepancies between the information in A Panorama of Hungarian Mathematics in the Twentieth Century, I and in the statement of the University of California (see below). Furthermore, in the announcement, contrary to the information in the “Mathematics Genealogy Project”, the year 1955 is shown instead of the year 1953 for obtaining the Docteur ès sciences .
2. ↑ Detlef Laugwitz : Differentialgeometrie (=  mathematical guidelines ). 2nd revised edition. Teubner Verlag , Stuttgart 1968, p. 161 .
3. ^ Wilhelm Klingenberg : A lecture on differential geometry (=  Heidelberger Taschenbücher . Volume 107 ). Springer Verlag , Berlin (among others) 1973, ISBN 3-540-06253-X , p. 24 .
4. ↑ Such a space curve is therefore not ambient isotopic to the trivial node .