Volker Strassen | |
---|---|
Born | |
Nationality | German |
Alma mater | University of Göttingen |
Known for | Strassen algorithm |
Scientific career | |
Fields | Mathematics |
Institutions | University of Konstanz |
Doctoral advisor | Konrad Jacobs |
Doctoral students | Peter Bürgisser Joachim von zur Gathen |
Volker Strassen (born April 29, 1936) is a German mathematician, a professor emeritus in the department of mathematics and statistics at the University of Konstanz. [1]
For important contributions to the analysis of algorithms he has received many awards, including the Cantor medal, [2] the Konrad Zuse Medal, [3] the Paris Kanellakis Award for work on randomized primality testing, [4] the Knuth Prize for "seminal and influential contributions to the design and analysis of efficient algorithms." [5]
Strassen was born on April 29, 1936, in Düsseldorf-Gerresheim. [2] After studying music, philosophy, physics, and mathematics at several German universities, [2] he received his Ph.D. in mathematics in 1962 from the University of Göttingen under the supervision of Konrad Jacobs . [6] He then took a position in the department of statistics at the University of California, Berkeley while performing his habilitation at the University of Erlangen-Nuremberg, where Jacobs had since moved. [2] In 1968, Strassen moved to the Institute of Applied Mathematics at the University of Zurich, where he remained for twenty years before moving to the University of Konstanz in 1988. [2] He retired in 1998. [4]
Strassen began his researches as a probabilist; his 1964 paper An Invariance Principle for the Law of the Iterated Logarithm defined a functional form of the law of the iterated logarithm, showing a form of scale invariance in random walks. This result, now known as Strassen's invariance principle or as Strassen's law of the iterated logarithm, has been highly cited and led to a 1966 presentation at the International Congress of Mathematicians.
In 1969, Strassen shifted his research efforts towards the analysis of algorithms with a paper on Gaussian elimination, introducing Strassen's algorithm, the first algorithm for performing matrix multiplication faster than the O(n3) time bound that would result from a naive algorithm. In the same paper he also presented an asymptotically fast algorithm to perform matrix inversion, based on the fast matrix multiplication algorithm. This result was an important theoretical breakthrough, leading to much additional research on fast matrix multiplication, and despite later theoretical improvements it remains a practical method for multiplication of dense matrices of moderate to large sizes. In 1971 Strassen published another paper together with Arnold Schönhage on asymptotically fast integer multiplication based on the fast Fourier transform; see the Schönhage–Strassen algorithm. Strassen is also known for his 1977 work with Robert M. Solovay on the Solovay–Strassen primality test, the first method to show that testing whether a number is prime can be performed in randomized polynomial time and one of the first results to show the power of randomized algorithms more generally.
In 1999 Strassen was awarded the Cantor medal, [2] and in 2003 he was co-recipient of the Paris Kanellakis Award with Robert Solovay, Gary Miller, and Michael Rabin for their work on randomized primality testing. [4] In 2008 he was awarded the Knuth Prize for "seminal and influential contributions to the design and analysis of efficient algorithms." [5] In 2011 he won the Konrad Zuse Medal of the Gesellschaft für Informatik. [3] [7] In 2012 he became a fellow of the American Mathematical Society. [8]
A multiplication algorithm is an algorithm to multiply two numbers. Depending on the size of the numbers, different algorithms are more efficient than others. Efficient multiplication algorithms have existed since the advent of the decimal numeral system.
Plankalkül is a programming language designed for engineering purposes by Konrad Zuse between 1942 and 1945. It was the first high-level programming language to be designed for a computer.
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A primality test is an algorithm for determining whether an input number is prime. Among other fields of mathematics, it is used for cryptography. Unlike integer factorization, primality tests do not generally give prime factors, only stating whether the input number is prime or not. Factorization is thought to be a computationally difficult problem, whereas primality testing is comparatively easy. Some primality tests prove that a number is prime, while others like Miller–Rabin prove that a number is composite. Therefore, the latter might more accurately be called compositeness tests instead of primality tests.
The Miller–Rabin primality test or Rabin–Miller primality test is a probabilistic primality test: an algorithm which determines whether a given number is likely to be prime, similar to the Fermat primality test and the Solovay–Strassen primality test.
In probability theory, the law of the iterated logarithm describes the magnitude of the fluctuations of a random walk. The original statement of the law of the iterated logarithm is due to A. Ya. Khinchin (1924). Another statement was given by A. N. Kolmogorov in 1929.
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The Solovay–Strassen primality test, developed by Robert M. Solovay and Volker Strassen in 1977, is a probabilistic test to determine if a number is composite or probably prime. The idea behind the test was discovered by M. M. Artjuhov in 1967 (see Theorem E in the paper). This test has been largely superseded by the Baillie–PSW primality test and the Miller–Rabin primality test, but has great historical importance in showing the practical feasibility of the RSA cryptosystem. The Solovay–Strassen test is essentially an Euler–Jacobi probable prime test.
The Schönhage–Strassen algorithm is an asymptotically fast multiplication algorithm for large integers, published by Arnold Schönhage and Volker Strassen in 1971. It works by recursively applying fast Fourier transform (FFT) over the integers modulo 2n+1. The run-time bit complexity to multiply two n-digit numbers using the algorithm is in big O notation.
Arnold Schönhage is a German mathematician and computer scientist.
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Robert Martin Solovay is an American mathematician working in set theory.
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