Cornelius Lanczos
Cornelius Lanczos ( [ la ː ntsoʃ ]; Kornel also Löwy, Kornel Lanczos; born February 2, 1893 in Székesfehérvár, Austria - Hungary, † June 25, 1974 in Budapest) was a Hungarian mathematician and physicist.
Life
Lanczos was born the son of the lawyer Carolus Loewy, attended the Jewish elementary school and then a Catholic high school. His real name was Kornel Loewy, in the anti-German climate of what was then Hungary but he changed it to Kornel Lanczos, and under this name he published in Germany later. In 1910 he began his studies in Budapest, where he studied with Leopold Fejér and Others physics at Eotvos Lorand and mathematics. After graduating in 1915 he was an assistant at the Polytechnic and obtained his doctorate in 1921 with Rudolf Ortvay at the University of Szeged on a theme of relativity ( " The function-theoretic relations of Maxwell's Aether Equations" ), which he sent to Albert Einstein, who received it favorably. From the politically troubled Hungary - where he also took no position as a Jew - he first went to the University of Freiburg as an assistant to Franz Himstedt, then was at the University of Frankfurt as an assistant to Erwin Madelung, where he was also on the new edition of his " Mathematical tools of the physicist " cooperated, where he also got about Richard Courant contacts Hilbert school in Göttingen. In between, he was after his habilitation in 1927 in Frankfurt 1928/ 29, with a grant from the Emergency Association of German Science Wizard by Einstein in Berlin, with whom he corresponded later and his life he worshiped. He published the general theory of relativity and cosmology, and also tried from the late 1920s to find a unified field theories, which include quantum mechanics. 1922 to 1924 he was secretary of the German Physical Society. In 1931 he was a visiting professor of theoretical physics at Purdue University in West Lafayette, Indiana, where he remained from 1932 entirely, since the return to Germany was impossible due to the persecution of the Jews ( he was still in 1932 associate professor in Frankfurt). From 1938 he turned there to numerical mathematics. Because he felt isolated among physicists at Purdue, he went in 1946 as an applied mathematician at Boeing in Seattle, where he had worked in 1944. In 1949 he went to the Department of Numerical Mathematics of the National Bureau of Standards of the USA in Los Angeles ( where he also already 1943 quarters during the war worked ), as a colleague of Otto Szasz, Olga Taussky - Todd and John Todd. The political atmosphere of the McCarthy years did not suit him, and he went in 1952 at the invitation of Erwin Schrödinger to the Institute for Advanced Study in Dublin, but was often a visiting scholar at American universities or in industry (among Ford Motor Company). In 1974, he died during a research stay at the University of Budapest from a heart attack.
In 1960 he received the Chauvenet Prize of the Mathematical Association of America. In 1958 he gave a plenary lecture at the International Congress of Mathematicians in Edinburgh (Extended boundary value problems ).
He was married twice and had a son from his first marriage.
Work
Lanczos also dealt with mathematical physics, especially with general relativity. In 1925, he learned early on the quantum theoretical matrix mechanics of Werner Heisenberg, Max Born and Pascual Jordan know and tried it a " field uniform " representation with integral equations to give the corresponding to the eigenvalues of the matrices eigenfunctions as core functions. Here it but Erwin Schrödinger came before, instead of integral equations used differential equations. Lanczos ' work has been recognized by Bartel Leendert later van der Waerden. 1930/1931, he investigated the Stark effect in strong electric fields. He wrote in 1949 a book on the variational principles of mechanics.
Lanczos made numerous contributions to numerical mathematics. He brought out in the years 1950 and 1952zwei article about a method he called the minimized iterates method for solving Fredholm integral equations, systems of linear equations and eigenvalue problems. The two articles form the basis of today's so-called class of Lanczos method and were the first of the Krylov subspace method still used today. The older Krylov subspace method of Alexei Nikolaevich Krylov of 1931 and Karl Hessenberg from 1940 are not as efficient to implement; the method of Lanczos represents a significant improvement
In 1964 Lanczos his methods for the approximation of the gamma function. He also dealt with Chebyshev functions. In 1940 he published what was later rediscovered by John W. Tukey as a Fast Fourier Transform.