Alfréd Rényi

Alfréd Rényi [ ɒlfre ː ː d re ɲi ] ( born March 20, 1921 in Budapest, † February 1, 1970 in Budapest) was a Hungarian mathematician who dealt primarily with probability theory and number theory.

Life and work

Rényis father Artur was an engineer ( whose father was originally Rosenthal and immigrated from Germany ) and his mother, Barbara, Alexandra, the daughter of the professor of philosophy in Budapest Bernát Alexander. In high school located Renyi initially was more interested in classical languages ​​and Astronomy, turned under the influence of his teacher, the mathematician Rózsa Péter but the mathematics. Since access for Jewish students was limited, he was first in 1939 despite shining as Best Baccalaureate his school do not study, but worked half a year in a factory and a shipyard. He studied at the University of Budapest, among others at Lipót Fejér and Pál Turán, where he made his degree in 1944. In 1944 he was briefly in a labor camp of the Hungarian fascists, but he managed to escape to the West and go underground in Budapest, where he dressed as a soldier, his parents freed from the ghetto before shipment. In March 1945 he received his doctorate at the University of Szeged in Frigyes Riesz on Analysis.

In 1946, he was with Yuri Linnik and Vinogradov Ivan Matveyitch in Leningrad, where he wrote a second thesis, which sparked the so-called quasi- Goldbach conjecture. In 1932 Theodor Estermann had proved under the assumption of the validity of the generalized Riemann 's conjecture for Dirichlet L-functions, that every sufficiently large even number can be represented as the sum of a prime and a number with a maximum of 6 factors. Renyi now proved that there exists a constant K such that every even number prime factors can be written as a sum of a prime and a number with at most K. Renyi succeeded this evidence using a proven record of him on the zeros of Dirichlet L-functions and methods of the great screen of Yuri Linnik and without the use of the Riemann Hypothesis as a prerequisite.

In the fall of 1947, Rényi assistant professor and lecturer at the University of Budapest and was also an associate from 1949 to 1950 at the University of Debrecen. In 1950 he became director of the Institute of Applied Mathematics of the Hungarian Academy of Sciences, which later became the Mathematical Research Institute (now as Alfred Renyi Institute named after him). Rényi in 1952 became dean of the Faculty of Eötvös Lorand University of probability theory of Budapest. He held both positions he held until his death. He has been a visiting professor at the University of Michigan, the University of North Carolina, Stanford University, the University of Erlangen and a Fellow of Churchill College, Cambridge.

Rényi dealt next to number theory and probability theory and statistics with many areas of mathematics, including combinatorics, graph theory, analysis, and information theory, where he introduced as a generalization of the Shannon entropy, the Rényi entropy. He is considered the founder of the Hungarian school of probability theory. He gave a probabilistic formulation of Linniks Big sieve of analytic number theory and applied not only probabilistic methods in number theory, but also vice versa number-theoretic methods in probability theory, where, for example, follow the mixture sets of Renyi from Linniks Large sieve method. He published 32 works together with Paul Erdős, one of which is known, in particular a paper on random graphs. He was interested in the philosophy of mathematics, mathematics in ancient history, mathematics education, and recreational mathematics. He wrote several popular science books. The book diary on information theory, he could not finish, it was published after his death by Gyula Katona.

He introduced a new axiomatic justification of the probability theory, a (conditional probabilities with spaces ) over which he delivered in 1954 at the International Congress of Mathematicians in Amsterdam and about which he published in 1970 a book.

Rényi was a corresponding full and since 1956 a member of the Hungarian Academy of Sciences since 1949. 1949 and 1954 he was awarded the Kossuth Prize. 1949 to 1955 he was secretary of the Janos Bolyai Mathematical Society. 1965 to 1969 he was the International Statistical Institute ago. He was a Fellow of the Institute of mathematical Statistics. He was editor of Studia Mathematica Hungarica Scientiarum and the editorial board of Acta Mathematica, among others, Journal of Probability Theory, Journal of Applied Probability and Journal of Combinatorial Analysis. In 1962 he was invited speaker at the International Congress of Mathematicians in Stockholm ( On the theory of outstanding observations ) and 1958 in Edinburgh ( Probabilistic methods in number theory ).

He was ( known from 1924 to 1969, as Kató Renyi ) since 1946 with the mathematician Katalin schoolyard married, with whom he also published. Together they had a daughter Zsuzsa.

Descent

Writings

• Probability. With an Appendix on Information Theory, German VEB Verlag der Wissenschaften, Berlin 1962, 4th Edition 1973 (English Edition North Holland 1970)
• Dialogues on Mathematics, Birkhäuser 1967
• Letters on probability, Birkhauser 1969
• Diary on Information Theory, Berlin, German Academic Publishers 1982
• Foundations of probability in 1970

Quote

A mathematician is a machine that turns coffee into sentences.