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H. E. Richert
Hans-Egon Richert (June 2, 1924 – November 25, 1993) was a German mathematician who worked primarily in analytic number theory. He is the author (with Heini Halberstam) of a definitive book on sieve theory. Life and education Hans-Egon Richert was born in 1924 in Hamburg, Germany. He attended the University of Hamburg and received his Ph.D under Max Deuring in 1950. He held a temporary chair at the University of Göttingen and then a newly created chair at the University of Marburg. In 1972 he moved to the University of Ulm, where he remained until his retirement in 1991. He died on November 25, 1993 in Blaustein, near Ulm, Germany. Work Richert worked primarily in analytic number theory, and beginning around 1965 started a collaboration with Heini Halberstam and shifted his focus to sieve theory. For many years he was a chairman of the Analytic Number Theory meetings at the Mathematical Research Institute of Oberwolfach. Analytic number theory Richert made c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heini Halberstam
Heini Halberstam (11 September 1926[Doreen Halberstam, wife] – 25 January 2014) was a Czech-born British mathematician, working in the field of analytic number theory. He is remembered in part for the Elliott–Halberstam conjecture from 1968. Life and career Halberstam was born in Most (Most District), Most, Czechoslovakia and died in Champaign, Illinois, US. His father died when he was very young. After Adolf Hitler's annexation of the Sudetenland, he and his mother moved to Prague. At the age of twelve, as the Nazi occupation progressed, he was one of the 669 children saved by Nicholas Winton, Sir Nicholas Winton, who organized the Kindertransport, a train that allowed those children to leave Nazi-occupied territory. He was sent to England, where he lived during World War II, World War II. He obtained his PhD in 1952, from University College London, University College, London, under supervision of Theodor Estermann. From 1962 until 1964, Halberstam was Erasmus Smith's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1993 Deaths
File:1993 Events Collage.png, From left, clockwise: The Oslo I Accord is signed in an attempt to resolve the Israeli–Palestinian conflict; The Russian White House is shelled during the 1993 Russian constitutional crisis; Czechoslovakia is peacefully dissolved into the Czech Republic and Slovakia; In the United States, the ATF besieges a compound belonging to David Koresh and the Branch Davidians in a search for illegal weapons, which ends in the building being set alight and killing most inside; Eritrea gains independence; A major snow storm passes over the United States and Canada, leading to over 300 fatalities; Drug lord and narcoterrorist Pablo Escobar is killed by Colombian special forces; Ramzi Yousef and other Islamic terrorists detonate a truck bomb in the subterranean garage of the North Tower of the World Trade Center in the United States., 300x300px, thumb rect 0 0 200 200 Oslo I Accord rect 200 0 400 200 1993 Russian constitutional crisis rect 400 0 600 200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1924 Births
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album '' Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Montgomery (mathematician)
Hugh Lowell Montgomery (born August 26, 1944) is an American mathematician, working in the fields of analytic number theory and mathematical analysis. As a Marshall scholar, Montgomery earned his Ph.D. from the University of Cambridge. For many years, Montgomery has been teaching at the University of Michigan. He is best known for Montgomery's pair correlation conjecture, his development of the large sieve methods and for co-authoring (with Ivan M. Niven and Herbert Zuckerman) one of the standard introductory number theory texts, ''An Introduction to the Theory of Numbers'', now in its fifth edition (). In 1974 Montgomery was an invited speaker of the International Congress of Mathematicians (ICM) in Vancouver. In 2012 he became a fellow of the American Mathematical Society. Bibliography * * Davenport, Harold. ''Multiplicative number theory''. Third edition. Revised and with a preface by Hugh L. Montgomery. Graduate Texts in Mathematics, 74. Springer-Verlag, New York, 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chen's Theorem
In number theory, Chen's theorem states that every sufficiently large parity (mathematics), even number can be written as the sum of either two prime number, primes, or a prime and a semiprime (the product of two primes). History The theorem was first stated by China, Chinese mathematician Chen Jingrun in 1966, with further details of the mathematical proof, proof in 1973. His original proof was much simplified by P. M. Ross in 1975. Chen's theorem is a giant step towards the Goldbach's conjecture, and a remarkable result of the sieve theory, sieve methods. Chen's theorem represents the strengthening of a previous result due to Alfréd Rényi, who in 1947 had shown there exists a finite ''K'' such that any even number can be written as the sum of a prime number and the product of at most ''K'' primes. Variations Chen's 1973 paper stated two results with nearly identical proofs. His Theorem I, on the Goldbach conjecture, was stated above. His Theorem II is a result on the Twi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selberg Sieve
In number theory, the Selberg sieve is a technique for estimating the size of "sifted sets" of positive integers which satisfy a set of conditions which are expressed by congruences. It was developed by Atle Selberg in the 1940s. Description In terms of sieve theory the Selberg sieve is of ''combinatorial type'': that is, derives from a careful use of the inclusion–exclusion principle. Selberg replaced the values of the Möbius function which arise in this by a system of weights which are then optimised to fit the given problem. The result gives an ''upper bound'' for the size of the sifted set. Let A be a set of positive integers \le x and let P be a set of primes. Let A_d denote the set of elements of A divisible by d when d is a product of distinct primes from P. Further let A_1 denote A itself. Let z be a positive real number and P(z) denote the product of the primes in P which are \le z. The object of the sieve is to estimate :S(A,P,z) = \left\vert A \setminus \bigc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurkat–Richert Theorem
The Jurkat–Richert theorem is a mathematical theorem in sieve theory. It is a key ingredient in proofs of Chen's theorem on Goldbach's conjecture. It was proved in 1965 by Wolfgang B. Jurkat and Hans-Egon Richert. Statement of the theorem This formulation is from Diamond & Halberstam. Other formulations are in Jurkat & Richert, Halberstam & Richert, and Nathanson. Suppose ''A'' is a finite sequence of integers and ''P'' is a set of primes. Write ''A''''d'' for the number of items in ''A'' that are divisible by ''d'', and write ''P''(''z'') for the product of the elements in ''P'' that are less than ''z''. Write ω(''d'') for a multiplicative function In number theory, a multiplicative function is an arithmetic function ''f''(''n'') of a positive integer ''n'' with the property that ''f''(1) = 1 and f(ab) = f(a)f(b) whenever ''a'' and ''b'' are coprime. An arithmetic function ''f''(''n'') i ... such that ω(''p'')/''p'' is approximately the proportion of elements of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exponential Sum
In mathematics, an exponential sum may be a finite Fourier series (i.e. a trigonometric polynomial), or other finite sum formed using the exponential function, usually expressed by means of the function :e(x) = \exp(2\pi ix).\, Therefore, a typical exponential sum may take the form :\sum_n e(x_n), summed over a finite sequence of real numbers ''x''''n''. Formulation If we allow some real coefficients ''a''''n'', to get the form :\sum_n a_n e(x_n) it is the same as allowing exponents that are complex numbers. Both forms are certainly useful in applications. A large part of twentieth century analytic number theory was devoted to finding good estimates for these sums, a trend started by basic work of Hermann Weyl in diophantine approximation. Estimates The main thrust of the subject is that a sum :S=\sum_n e(x_n) is ''trivially'' estimated by the number ''N'' of terms. That is, the absolute value :, S, \le N\, by the triangle inequality, since each summand has absolute va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abelian Group
In mathematics, an abelian group, also called a commutative group, is a group in which the result of applying the group operation to two group elements does not depend on the order in which they are written. That is, the group operation is commutative. With addition as an operation, the integers and the real numbers form abelian groups, and the concept of an abelian group may be viewed as a generalization of these examples. Abelian groups are named after early 19th century mathematician Niels Henrik Abel. The concept of an abelian group underlies many fundamental algebraic structures, such as fields, rings, vector spaces, and algebras. The theory of abelian groups is generally simpler than that of their non-abelian counterparts, and finite abelian groups are very well understood and fully classified. Definition An abelian group is a set A, together with an operation \cdot that combines any two elements a and b of A to form another element of A, denoted a \cdot b. The symbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erdős–Fuchs Theorem
In mathematics, in the area of additive number theory, the Erdős–Fuchs theorem is a statement about the number of ways that numbers can be represented as a sum of elements of a given additive basis, stating that the average order of this number cannot be too close to being a linear function. The theorem is named after Paul Erdős and Wolfgang Heinrich Johannes Fuchs, who published it in 1956. Statement Let \mathcal\subseteq\mathbb be an infinite subset of the natural numbers and r_(n) its ''representation function'', which denotes the number of ways that a natural number n can be expressed as the sum of h elements of \mathcal (taking order into account). We then consider the ''accumulated representation function'' s_(x) := \sum_ r_(n), which counts (also taking order into account) the number of solutions to k_1 + \cdots + k_h \leqslant x, where k_1,\ldots,k_h \in \mathcal. The theorem then states that, for any given c>0, the relation s_(n) = cn + o\left(n^\log(n)^ \right) c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
