Alfréd Rényi (March 20, 1921 – February 1, 1970) was a Hungarian mathematician who made contributions in combinatorics and graph theory but mostly in probability theory. Events 1600 - The Linköping Bloodbath takes place on Maundy Thursday in Linköping, Sweden. Year 1921 ( MCMXXI) was a Common year starting on Saturday (link will display full 1921 calendar of the Gregorian calendar Events 1327 - Teenaged Edward III is crowned King of England, but the country is ruled by his mother Queen Year 1970 ( MCMLXX) was a Common year starting on Thursday (link shows full calendar of the 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. Combinatorics is a branch of Pure mathematics concerning the study of discrete (and usually finite) objects In Mathematics and Computer science, graph theory is the study of graphs: mathematical structures used to model pairwise relations between objects Probability theory is the branch of Mathematics concerned with analysis of random phenomena 
Rényi was born in Budapest to Artur Rényi and Barbara Alexander; his father was a mechanical engineer while his mother was the daughter of a philosopher and literary critic, Bernát Alexander. Budapest ( also /ˈbʊ-/) is the capital city of Hungary. As the largest city of Hungary it serves as the country's principal Political, He was prevented from enrolling in university in 1939 due to the anti-Jewish laws then in force, but enrolled at the University of Budapest in 1940 and finished his studies in 1944. At this point he was imprisoned in a labor camp, escaped, and completed his Ph.D. in 1947 at the University of Szeged, under the advisement of Frigyes Riesz. "PhD" redirects here for other uses see PhD (disambiguation. The University of Szeged is one of the most distinguished universities in Hungary and in Central Europe. Frigyes Riesz ( January 22, 1880 &ndash February 28, 1956) was a Mathematician who was born in Győr, Hungary  He married Katalin Schulhof, herself a mathematician, in 1946; his daughter Zsuzsa was born in 1948. After a brief assistant professorship at Budapest, he was appointed Professor Extraordinary at the University of Debrecen in 1949. The University of Debrecen is a major university located in Debrecen, Hungary.
He proved, using the large sieve, that there is a number K such that every even number is the sum of a prime number and a number that can be written as the product of at most K primes. In Mathematics, the large sieve is a method of Analytic number theory. See also Goldbach conjecture. Goldbach's conjecture is one of the oldest unsolved problems in Number theory and in all of Mathematics.
In information theory, he introduced the spectrum of Rényi entropies of order α, giving an important generalisation of the Shannon entropy and the Kullback-Leibler divergence. Information theory is a branch of Applied mathematics and Electrical engineering involving the quantification of Information. In Information theory, the Rényi entropy, a generalisation of Shannon entropy, is one of a family of functionals for quantifying the diversity uncertainty or randomness In Probability theory and Information theory, the Kullback–Leibler divergence (also information divergence, information gain, or relative The Rényi entropies give a spectrum of useful diversity indices, and lead to a spectrum of fractal dimensions. In Ecology, a diversity index is a statistic which is intended to measure the Biodiversity of an Ecosystem. In Fractal geometry, the fractal dimension, D, is a statistical quantity that gives an indication of how completely a Fractal appears to fill space as
He founded the Mathematical Institute in Budapest, now called The Alfréd Rényi Institute of Mathematics. Budapest ( also /ˈbʊ-/) is the capital city of Hungary. As the largest city of Hungary it serves as the country's principal Political, There are currently approximately 70 mathematicians doing research at the Institute.
He wrote 32 joint papers with Paul Erdős, the most well-known of which are his papers introducing the Erdős–Rényi model of random graphs. Paul Erdős ( Hungarian: Erdős Pál, in English occasionally Paul Erdos or Paul Erdös, March 26, 1913 &ndash In Graph theory, the Erdős-Rényi model, named for Paul Erdős and Alfréd Rényi, is either of two models for generating Random graphs including In Mathematics, a random graph is a graph that is generated by some Random process.  Alfréd Rényi is probably the source of the quote: "A mathematician is a device for turning coffee into theorems.", which is generally ascribed to Erdős.
He is also famous for having said, "If I feel unhappy, I do mathematics to become happy. If I am happy, I do mathematics to keep happy. "
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