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Alf Van Der Poorten
Alfred Jacobus (Alf) van der Poorten (16 May 1942 – 9 October 2010) was a Dutch-Australian number theorist, for many years on the mathematics faculties of the University of New South Wales and Macquarie University.... Biography Van der Poorten was born into a Jewish family in Amsterdam in 1942, after the German occupation began. His parents, David and Marianne van der Poorten, gave him into foster care with the Teerink family in Amersfoort, under the name "Fritsje"; the senior van der Poortens went into hiding, were caught by the Nazis, survived the concentration camps, and were reunited with van der Poorten and his two sisters after the war. The family moved to Sydney in 1951, travelling there aboard the SS Himalaya. Van der Poorten studied at Sydney Boys High School from 1955–59, and earned a high score in the Leaving Certificate Examination there. He spent a year in Israel and then studied mathematics at the University of New South Wales, where he earned a bachelor's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alf Van Der Poorten
Alfred Jacobus (Alf) van der Poorten (16 May 1942 – 9 October 2010) was a Dutch-Australian number theorist, for many years on the mathematics faculties of the University of New South Wales and Macquarie University.... Biography Van der Poorten was born into a Jewish family in Amsterdam in 1942, after the German occupation began. His parents, David and Marianne van der Poorten, gave him into foster care with the Teerink family in Amersfoort, under the name "Fritsje"; the senior van der Poortens went into hiding, were caught by the Nazis, survived the concentration camps, and were reunited with van der Poorten and his two sisters after the war. The family moved to Sydney in 1951, travelling there aboard the SS Himalaya. Van der Poorten studied at Sydney Boys High School from 1955–59, and earned a high score in the Leaving Certificate Examination there. He spent a year in Israel and then studied mathematics at the University of New South Wales, where he earned a bachelor's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles N
Charles is a masculine given name predominantly found in English and French speaking countries. It is from the French form ''Charles'' of the Proto-Germanic name (in runic alphabet) or ''*karilaz'' (in Latin alphabet), whose meaning was "free man". The Old English descendant of this word was '' Ċearl'' or ''Ċeorl'', as the name of King Cearl of Mercia, that disappeared after the Norman conquest of England. The name was notably borne by Charlemagne (Charles the Great), and was at the time Latinized as ''Karolus'' (as in ''Vita Karoli Magni''), later also as '' Carolus''. Some Germanic languages, for example Dutch and German, have retained the word in two separate senses. In the particular case of Dutch, ''Karel'' refers to the given name, whereas the noun ''kerel'' means "a bloke, fellow, man". Etymology The name's etymology is a Common Germanic noun ''*karilaz'' meaning "free man", which survives in English as churl (< Old English ''ċeorl''), which developed its depr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Dwork
Bernard Morris Dwork (May 27, 1923 – May 9, 1998) was an American mathematician, known for his application of ''p''-adic analysis to local zeta functions, and in particular for a proof of the first part of the Weil conjectures: the rationality of the zeta-function of a variety over a finite field. The general theme of Dwork's research was ''p''-adic cohomology and ''p''-adic differential equations. He published two papers under the pseudonym Maurizio Boyarsky. Career Dwork received his Ph.D. at Columbia University in 1954 under direction of Emil Artin (his formal advisor was John Tate); Nick Katz was one of his students.. For his proof of the first part of the Weil conjectures, Dwork received (together with Kenkichi Iwasawa) the Cole Prize in 1962.Memorial article – by |
Rational Functions
In mathematics, a rational function is any function that can be defined by a rational fraction, which is an algebraic fraction such that both the numerator and the denominator are polynomials. The coefficients of the polynomials need not be rational numbers; they may be taken in any field ''K''. In this case, one speaks of a rational function and a rational fraction ''over K''. The values of the variables may be taken in any field ''L'' containing ''K''. Then the domain of the function is the set of the values of the variables for which the denominator is not zero, and the codomain is ''L''. The set of rational functions over a field ''K'' is a field, the field of fractions of the ring of the polynomial functions over ''K''. Definitions A function f(x) is called a rational function if and only if it can be written in the form : f(x) = \frac where P\, and Q\, are polynomial functions of x\, and Q\, is not the zero function. The domain of f\, is the set of all values of x\, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcendental Number
In mathematics, a transcendental number is a number that is not algebraic—that is, not the root of a non-zero polynomial of finite degree with rational coefficients. The best known transcendental numbers are and . Though only a few classes of transcendental numbers are known—partly because it can be extremely difficult to show that a given number is transcendental—transcendental numbers are not rare. Indeed, almost all real and complex numbers are transcendental, since the algebraic numbers comprise a countable set, while the set of real numbers and the set of complex numbers are both uncountable sets, and therefore larger than any countable set. All transcendental real numbers (also known as real transcendental numbers or transcendental irrational numbers) are irrational numbers, since all rational numbers are algebraic. The converse is not true: not all irrational numbers are transcendental. Hence, the set of real numbers consists of non-overlapping rational, algebrai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recurrence Relation
In mathematics, a recurrence relation is an equation according to which the nth term of a sequence of numbers is equal to some combination of the previous terms. Often, only k previous terms of the sequence appear in the equation, for a parameter k that is independent of n; this number k is called the ''order'' of the relation. If the values of the first k numbers in the sequence have been given, the rest of the sequence can be calculated by repeatedly applying the equation. In ''linear recurrences'', the th term is equated to a linear function of the k previous terms. A famous example is the recurrence for the Fibonacci numbers, F_n=F_+F_ where the order k is two and the linear function merely adds the two previous terms. This example is a linear recurrence with constant coefficients, because the coefficients of the linear function (1 and 1) are constants that do not depend on n. For these recurrences, one can express the general term of the sequence as a closed-form expression o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integer Sequence
In mathematics, an integer sequence is a sequence (i.e., an ordered list) of integers. An integer sequence may be specified ''explicitly'' by giving a formula for its ''n''th term, or ''implicitly'' by giving a relationship between its terms. For example, the sequence 0, 1, 1, 2, 3, 5, 8, 13, ... (the Fibonacci sequence) is formed by starting with 0 and 1 and then adding any two consecutive terms to obtain the next one: an implicit description. The sequence 0, 3, 8, 15, ... is formed according to the formula ''n''2 − 1 for the ''n''th term: an explicit definition. Alternatively, an integer sequence may be defined by a property which members of the sequence possess and other integers do not possess. For example, we can determine whether a given integer is a perfect number, even though we do not have a formula for the ''n''th perfect number. Examples Integer sequences that have their own name include: *Abundant numbers *Baum–Sweet sequence *Bell numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Language
In theoretical computer science and formal language theory, a regular language (also called a rational language) is a formal language that can be defined by a regular expression, in the strict sense in theoretical computer science (as opposed to many modern regular expressions engines, which are augmented with features that allow recognition of non-regular languages). Alternatively, a regular language can be defined as a language recognized by a finite automaton. The equivalence of regular expressions and finite automata is known as Kleene's theorem (after American mathematician Stephen Cole Kleene). In the Chomsky hierarchy, regular languages are the languages generated by Type-3 grammars. Formal definition The collection of regular languages over an alphabet Σ is defined recursively as follows: * The empty language Ø is a regular language. * For each ''a'' ∈ Σ (''a'' belongs to Σ), the singleton language is a regular language. * If ''A'' is a regular language, ''A''* ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptic Curve
In mathematics, an elliptic curve is a smooth, projective, algebraic curve of genus one, on which there is a specified point . An elliptic curve is defined over a field and describes points in , the Cartesian product of with itself. If the field's characteristic is different from 2 and 3, then the curve can be described as a plane algebraic curve which consists of solutions for: :y^2 = x^3 + ax + b for some coefficients and in . The curve is required to be non-singular, which means that the curve has no cusps or self-intersections. (This is equivalent to the condition , that is, being square-free in .) It is always understood that the curve is really sitting in the projective plane, with the point being the unique point at infinity. Many sources define an elliptic curve to be simply a curve given by an equation of this form. (When the coefficient field has characteristic 2 or 3, the above equation is not quite general enough to include all non-singular cubic cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continued Fraction
In mathematics, a continued fraction is an expression (mathematics), expression obtained through an iterative process of representing a number as the sum of its integer part and the multiplicative inverse, reciprocal of another number, then writing this other number as the sum of its integer part and another reciprocal, and so on. In a finite continued fraction (or terminated continued fraction), the iteration/recursion is terminated after finitely many steps by using an integer in lieu of another continued fraction. In contrast, an infinite continued fraction is an infinite expression (mathematics), infinite expression. In either case, all integers in the sequence, other than the first, must be positive number, positive. The integers a_i are called the coefficients or terms of the continued fraction. It is generally assumed that the numerator of all of the fractions is 1. If arbitrary values and/or function (mathematics), functions are used in place of one or more of the numerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baker's Theorem
In transcendental number theory, a mathematical discipline, Baker's theorem gives a lower bound for the absolute value of linear combinations of logarithms of algebraic numbers. The result, proved by , subsumed many earlier results in transcendental number theory and solved a problem posed by Alexander Gelfond nearly fifteen years earlier. Baker used this to prove the transcendence of many numbers, to derive effective bounds for the solutions of some Diophantine equations, and to solve the class number problem of finding all imaginary quadratic fields with class number 1. History To simplify notation, let \mathbb be the set of logarithms to the base ''e'' of nonzero algebraic numbers, that is \mathbb = \left \, where \Complex denotes the set of complex numbers and \overline denotes the algebraic numbers (the algebraic completion of the rational numbers \Q). Using this notation, several results in transcendental number theory become much easier to state. For example the Hermite–L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File 770
''File 770'' is a long-running science fiction fanzine, newszine, and blog site published/administered by Mike Glyer. It has been published every year since 1978, and has won a record eight Hugo Awards for Best Fanzine, with the first win in 1984 and the most recent in 2018. History File 770 is named after the legendary room party held in Room 770 at Nolacon, the 9th World Science Fiction Convention in New Orleans, Louisiana, that upstaged the other events at the 1951 Worldcon. Glyer started ''File 770'' in 1978 as a mimeographed print fanzine to report on fan clubs, conventions, fannish projects, fans, fanzines and SF awards, with articles written in a "no-nonsense style". In the 1990s, Glyer moved production of the fanzine to computer desktop publishing, and on January 15, 2008, he began publishing ''File 770'' as a blog on the internet. A print version of ''File 770'' has been produced every year from 1978 to the present. eFanzines.com began hosting PDF versions of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
