Cornelius Lanczos ( Lánczos Kornél) ("Lanzosh", approximate pronunciation 'LAN-sosh'), born Kornél Löwy (February 2, 1893–June 25, 1974), was a Hungarian mathematician and physicist. Events 962 - Translatio imperii: Pope John XII crowns Otto I Holy Roman Emperor, the first Holy Roman Emperor Year 1893 ( MDCCCXCIII) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common Events 524 - Battle of Vézeronce, the Franks defeat the Burgundians Year 1974 ( MCMLXXIV) was a Common year starting on Tuesday (link will display full calendar of the 1974 Gregorian calendar. Hungary (Magyarország 'mɔɟɔrorsaːg) officially in English the Republic of Hungary ( Magyar Köztársaság, literally Magyar (Hungarian Republic A mathematician is a person whose primary area of study and research is the field of Mathematics. A physicist is a Scientist who studies or practices Physics. Physicists study a wide range of physical phenomena in many branches of physics spanning

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. In General relativity, an exact solution is a Lorentzian manifold equipped with certain tensor fields which are taken to model states of ordinary matter The Einstein field equations ( EFE) or Einstein's equations are a set of ten equations in Einstein 's theory of General relativity in which the In General relativity, a fluid solution is an exact solution of the Einstein field equation in which the gravitational field is produced entirely by the This was later rediscovered by Willem Jacob van Stockum and is known today as the van Stockum dust. Willem Jacob van Stockum ( November 20 1910 - June 10 1944) was a physicist who made an important contribution to the early development of In General relativity, the van Stockum dust is an exact solution of the Einstein field equation in which the gravitational field is generated by dust rotating 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. In a Lorentzian manifold, a closed timelike curve (CTC is a Worldline of a material particle in Spacetime that is "closed" returning to its Lanczos served as assistant to Albert Einstein during the period 1928–29. Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical

He did pioneering work on what is now called the fast Fourier transform (1940), but the significance of his discovery was not appreciated at the time and today the FFT is credited to Cooley and Tukey (1965). The Cooley-Tukey Algorithm, named after JW Cooley and John Tukey, is the most common Fast Fourier transform (FFT algorithm (As a matter of fact, similar claims can be made for several other mathematicians; some even name Carl Friedrich Gauss as a progenitor of the FFT. Johann Carl Friedrich Gauss (ˈɡaʊs, Gauß Carolus Fridericus Gauss ( 30 April 1777 – 23 February 1855) was a German )

Working in Los Angeles at the US 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 algorithm is an iterative algorithm invented by Cornelius Lanczos that is an adaptation of power methods to find Eigenvalues and Eigenvectors In Mathematics, given a Linear transformation, an of that linear transformation is a nonzero vector which when that transformation is applied to it changes
• the Lanczos approximation for the gamma function. In Mathematics, the Lanczos approximation is a method for computing the Gamma function numerically published by Cornelius Lanczos in 1964
• 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. In Mathematics, the conjugate gradient method is an Algorithm for the Numerical solution of particular systems of linear equations, namely those In Mathematics, a system of linear equations (or linear system) is a collection of Linear equations involving the same set of Variables For example In Differential geometry, the Weyl curvature tensor, named after Hermann Weyl, is the Traceless component of the Riemann curvature 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

Lanczos resampling Lanczos_resampling is based on a windowed sync function as a practical upsampling filter approximating the ideal sync function. Lanczos resampling ("Lanzosh" is a Multivariate interpolation method used to compute new values for any digitally sampled data Lanczos resampling is widely used used in video up-sampling 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. McCarthyism is a term describing the intense anti-communist suspicion in the United States in a period that lasted roughly from the late 1940s to the late 1950s In 1952 he chose to leave the USA and move to the School of Theoretical Physics at the Dublin Institute for Advanced Studies in Ireland where he succeeded Schrödinger. The Dublin Institute for Advanced Studies ( DIAS) (Institiúid Ard-Léinn Bhaile Átha Cliath Dublin, Ireland was established When at D. I. A. S. he wrote the classic book, "Applied Analysis" (1956).

References

• Lanczos, Cornelius; and William R. Davis (ed. ) (1998). Collected published papers with commentaries. Raleigh, N. C. : North Carolina State University. ISBN 0-929493-01-X.  
• Lanczos, Cornelius (1970). The Variational Principles of Mechanics. Toronto: University of Toronto Press. ISBN 0-8020-1743-6.  
• Lanczos, Cornelius (1962). "The splitting of the Riemann tensor". Rev. Modern Phys. 34: 379. doi:10.1103/RevModPhys.34.379. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
• Lanczos, Cornelius (1924). "Über eine stationäre kosmologie im sinne der Einsteinischen Gravitationstheories". Zeitschr. f. Phys. 21: 73. doi:10.1007/BF01328251. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  

External links

• O'Connor, John J. & Robertson, Edmund F. , “Cornelius Lanczos”, MacTutor History of Mathematics archive 
• Cornelius Lanczos, Collected published papers with commentaries, published by North Carolina State University
• Photo gallery of Lanczos by Nicholas Higham