 Cornelius Lanczos

"Lanczos" redirects here. For resampling method, see Lanczos resampling.
Cornelius Lanczos Born February 2, 1893
SzékesfehérvárDied June 25, 1974 (aged 81)
BudapestNationality Hungarian Jewish Fields Mathematics
Theoretical physicsAlma mater University of Szeged Doctoral advisor Rudolf Ortvay Other academic advisors Loránd Eötvös, Leopold Fejér, Franz Himstedt, Erwin Madelung Cornelius (Cornel) Lanczos (Hungarian: Lánczos Kornél, Hungarian pronunciation: [ˈlaːntsoʃ]) (until 1906) Löwy (Lőwy) Kornél was a HungarianJewish mathematician and physicist, who was born on February 2, 1893, and died on June 25, 1974.
He was born in Székesfehérvár to Karl Löwy (Lőwy Károly) and Adél Hahn.
Lanczos' Ph.D. thesis (1921) was on relativity theory. In 1924 he discovered an exact solution of the Einstein field equation which represents a cylindrically symmetric rigidly rotating configuration of dust particles. This was later rediscovered by Willem Jacob van Stockum and is known today as the van Stockum dust. It is one of the simplest known exact solutions in general relativity and regarded as an important example, in part because it exhibits closed timelike curves. Lanczos served as assistant to Albert Einstein during the period of 1928–29.
He did pioneering work along with G.C. Danielson on what is now called the fast Fourier transform (FFT, 1940), but the significance of his discovery was not appreciated at the time and today the FFT is credited to Cooley and Tukey (1965). (As a matter of fact, similar claims can be made for several other mathematicians, including Carl Friedrich Gauss.^{[1]})
Working in Washington DC at the U.S. National Bureau of Standards after 1949 Lanczos developed a number of techniques for mathematical calculations using digital computers, including:
 the Lanczos algorithm for finding eigenvalues of large symmetric matrices.
 the Lanczos approximation for the gamma function.
 the conjugate gradient method for solving systems of linear equations
In 1962, Lanczos showed that the Weyl tensor, which plays a fundamental role in general relativity, can be obtained from a tensor potential which is now called the Lanczos potential.
Lanczos resampling is based on a windowed sinc function as a practical upsampling filter approximating the ideal sinc function. Lanczos resampling is widely used in video upsampling for digital zoom applications.
Lanczos was an outstanding physics teacher. Books such as The Variational Principles of Mechanics (1949) show his explanatory ability and enthusiasm for the subject.
During the McCarthy era Lanczos came under suspicion for possible Communist links. In 1952 he chose to leave the U.S. and move to the School of Theoretical Physics at the Dublin Institute for Advanced Studies in Ireland where he succeeded Schrödinger^{[2]}. When at D.I.A.S. he wrote the classic book, "Applied Analysis" (1956).
According to a short speech delivered Oct 1, 2010 during Lanczos' induction to the NIST Portrait Gallery of Distinguished Staff, his daughterinlaw described his return to Hungary in 1939 from his thenposition at Purdue University, when he attempted to convince his family to return to the US with him due to the antiJewish Nazi threat. His wife was too ill to travel, and died several weeks later from tuberculosis. He was only able to extricate his 5 year old son and return to the US just before the war began. When the Nazis purged Hungary of Jews in 1944, only his aunt and a nephew survived. That son married, moved to Seattle and raised two sons. Upon hearing of the birth of his first grandson by letter while in Ireland, he replied in his own letter that the boy "was proof that Hitler did not win."
References
 Lanczos, Cornelius; and William R. Davis (ed.) (1998). Collected published papers with commentaries. Raleigh, N.C.: North Carolina State University. ISBN 092949301X.
 Lanczos, Cornelius (1970). The Variational Principles of Mechanics. Toronto: University of Toronto Press. ISBN 0802017436.
 Lanczos, Cornelius (1962). "The splitting of the Riemann tensor". Rev. Modern Phys. 34 (3): 379. Bibcode 1962RvMP...34..379L. doi:10.1103/RevModPhys.34.379.
 Lanczos, Cornelius (1924). "Über eine stationäre Kosmologie im Sinne der Einsteinischen Gravitationstheorie". ZeitschrARRAY. Phys. 21: 73. Bibcode 1924ZPhy...21...73L. doi:10.1007/BF01328251.
 Brendan Scaife (1974). Studies in Numerical Analysis: Papers in Honour of Cornelius Lanczos. Dublin; London ; New York: Academic Press. ISBN 0126211507.
External links
 O'Connor, John J.; Robertson, Edmund F., "Cornelius Lanczos", MacTutor History of Mathematics archive, University of St Andrews, http://wwwhistory.mcs.standrews.ac.uk/Biographies/Lanczos.html.
 Cornelius Lanczos, Collected published papers with commentaries, published by North Carolina State University
 Photo gallery of Lanczos by Nicholas Higham
Categories: 20thcentury mathematicians
 American expatriates in Ireland
 American people of HungarianJewish descent
 American Jews
 Jewish scientists
 Hungarian mathematicians
 Hungarian physicists
 Irish Jews
 Irish mathematicians
 Numerical analysts
 Hungarian emigrants to the United States
 Hungarian Jews
 People from Székesfehérvár
 1893 births
 1974 deaths
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Cornelius Lanczos — ((hu) Lánczos Kornél) (né Kornél Löwy le 2 février 1893 à Székesfehérvár – 25 juin 1974 à Budapest) était un mathématicien et physicien hongrois. Sommaire 1 Biographie 2 Annexes … Wikipédia en Français
Cornelius Lanczos — ([ˈlaːntsoʃ]; auch Kornél Löwy, Kornél Lánczos; * 2. Februar 1893 in Székesfehérvár, Österreich Ungarn; † 25. Juni 1974 in Budapest) war ein ungarischer Mathematiker und Physiker. Inhaltsverzeichnis 1 Leben 2 Werk … Deutsch Wikipedia
Lanczos — Cornelius Lanczos ([ˈlaːntsoʃ]; auch Kornél Löwy, Kornél Lánczos), (* 2. Februar 1893 in Székesfehérvár, Österreich Ungarn; † 25. Juni 1974 in Budapest) war ein ungarischer Mathematiker und Physiker. Inhaltsverzeichnis 1 Leben 2 Werk … Deutsch Wikipedia
Cornelius — Gender Male Origin Word/Name Latin Cornelius is a Roman family name and a masculine given name. It could be derived from Latin cornu horn .[1] People, places and things named Cornelius include … Wikipedia
Lanczos approximation — In mathematics, the Lanczos approximation is a method for computing the Gamma function numerically, published by Cornelius Lanczos in 1964. It is a practical alternative to the more popular Stirling s approximation for calculating the Gamma… … Wikipedia
LanczosProzess — Das Lanczos Verfahren[1] (nach Cornelius Lanczos) ist sowohl ein iterativer Algorithmus zur Bestimmung einiger Eigenwerte und eventuell der zugehörigen Eigenvektoren einer Matrix, als auch ein iterativer Algorithmus zur approximativen Lösung… … Deutsch Wikipedia
Lanczos algorithm — The Lanczos algorithm is an iterative algorithm invented by Cornelius Lanczos that is an adaptation of power methods to find eigenvalues and eigenvectors of a square matrix or the singular value decomposition of a rectangular matrix. It is… … Wikipedia
LanczosVerfahren — Das Lanczos Verfahren[1] (nach Cornelius Lanczos) ist sowohl ein iterativer Algorithmus zur Bestimmung einiger Eigenwerte und eventuell der zugehörigen Eigenvektoren einer Matrix, als auch ein iterativer Algorithmus zur approximativen Lösung… … Deutsch Wikipedia
LanczosFilter — Graph des Lanczos Filters für a=3 Der Lanczos Filter ist ein häufig in der Computergrafik eingesetzter Rekonstruktionsfilter. Er wurde 1979 vom Meteorologen Claude E. Duchon entwickelt und ist nach dem ungarischen Mathematiker Cornelius Lanczos… … Deutsch Wikipedia
Lanczos tensor — There are two different tensors sometime referred to as the Lanczos tensor (both named after Cornelius Lanczos):* A tensor in the theory of quadratic Lagrangians, which vanishes in four dimensions. * The potential tensor H for the Weyl tensor C … Wikipedia