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Irrationality Measure
In mathematics, an irrationality measure of a real number x is a measure of how "closely" it can be Diophantine approximation, approximated by Rational number, rationals. If a Function (mathematics), function f(t,\lambda) , defined for t,\lambda>0, takes positive real values and is strictly decreasing in both variables, consider the following Inequality (mathematics), inequality: :0 \frac 1 for all integers p,q with q \geq q(\varepsilon) then the least such \beta is called the irrationality base of x and is represented as \beta(x). If no such \beta exists, then \beta(x)=\infty and x is called a ''super Liouville number''. If a real number x is given by its Continued fraction, simple continued fraction expansion x = [a_0; a_1, a_2, ...] with convergents p_i/q_i then it holds: :\beta(x)=\limsup_\frac =\limsup_\frac. Examples Any real number x with finite irrationality exponent \mu(x)1 has irrationality exponent \mu(x)=\infty and is a Liouville number. The number L=[1;2,2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dedekind Cut- Square Root Of Two
Julius Wilhelm Richard Dedekind (; ; 6 October 1831 – 12 February 1916) was a German mathematician who made important contributions to number theory, abstract algebra (particularly ring theory), and the Peano axioms, axiomatic foundations of arithmetic. His best known contribution is the definition of real numbers through the notion of Dedekind cut. He is also considered a pioneer in the development of modern set theory and of the philosophy of mathematics known as ''logicism''. Life Dedekind's father was Julius Levin Ulrich Dedekind, an administrator of TU Braunschweig, Collegium Carolinum in Braunschweig. His mother was Caroline Henriette Dedekind (née Emperius), the daughter of a professor at the Collegium. Richard Dedekind had three older siblings. As an adult, he never used the names Julius Wilhelm. He was born in Braunschweig (often called "Brunswick" in English), which is where he lived most of his life and died. His body rests at Braunschweig Main Cemetery. He first a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcendental Number
In mathematics, a transcendental number is a real or complex number that is not algebraic: that is, not the root of a non-zero polynomial with integer (or, equivalently, rational) coefficients. The best-known transcendental numbers are and . The quality of a number being transcendental is called transcendence. 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 form 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hurwitz's Theorem (number Theory)
In number theory, Hurwitz's theorem, named after Adolf Hurwitz, gives a bound on a Diophantine approximation. The theorem states that for every irrational number ''ξ'' there are infinitely many relatively prime integers ''m'', ''n'' such that \left , \xi-\frac\right , \sqrt and we let \xi = (1+\sqrt)/2 (the golden ratio) then there exist only ''finitely'' many relatively prime integers ''m'', ''n'' such that the formula above holds. The theorem is equivalent to the claim that the Markov constant of every number is larger than \sqrt. See also * Dirichlet's approximation theorem In number theory, Dirichlet's theorem on Diophantine approximation, also called Dirichlet's approximation theorem, states that for any real numbers \alpha and N , with 1 \leq N , there exist integers p and q such that 1 \leq q \leq N and ... * Lagrange number References * * * * {{cite book , author= Ivan Niven , title=Diophantine Approximations , publisher=Courier Corporation , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Markov Constant
In number theory, specifically in Diophantine approximation theory, the Markov constant M(\alpha) of an irrational number \alpha is the factor for which Dirichlet's approximation theorem can be improved for \alpha. History and motivation Certain numbers can be approximated well by certain rationals; specifically, the convergents of the continued fraction are the best approximations by rational numbers having denominators less than a certain bound. For example, the approximation \pi\approx\frac is the best rational approximation among rational numbers with denominator up to 56. Also, some numbers can be approximated more readily than others. Dirichlet proved in 1840 that the least readily approximable numbers are the rational numbers, in the sense that for every irrational number there exists infinitely many rational numbers approximating it to a certain degree of accuracy that only finitely many such rational approximations exist for rational numbers. Specifically, he prove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetration
In mathematics, tetration (or hyper-4) is an operation (mathematics), operation based on iterated, or repeated, exponentiation. There is no standard mathematical notation, notation for tetration, though Knuth's up arrow notation \uparrow \uparrow and the left-exponent ^b are common. Under the definition as repeated exponentiation, means , where ' copies of ' are iterated via exponentiation, right-to-left, i.e. the application of exponentiation n-1 times. ' is called the "height" of the function, while ' is called the "base," analogous to exponentiation. It would be read as "the th tetration of ". For example, 2 tetrated to 4 (or the fourth tetration of 2) is =2^=2^=2^=65536. It is the next hyperoperation after exponentiation, but before pentation. The word was coined by Reuben Louis Goodstein from tetra- (four) and iterated function, iteration. Tetration is also defined recursively as : := \begin 1 &\textn=0, \\ a^ &\textn>0, \end allowing for the holomorphic function, hol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Champernowne Constant
In mathematics, the Champernowne constant is a transcendental real constant whose decimal expansion has important properties. It is named after economist and mathematician D. G. Champernowne, who published it as an undergraduate in 1933. The number is defined by concatenating the base-10 representations of the positive integers: : . Champernowne constants can also be constructed in other bases similarly; for example, : and :. The Champernowne word or Barbier word is the sequence of digits of ''C''10 obtained by writing it in base 10 and juxtaposing the digits: : More generally, a ''Champernowne sequence'' (sometimes also called a ''Champernowne word'') is any sequence of digits obtained by concatenating all finite digit-strings (in any given base) in some recursive order. For instance, the binary Champernowne sequence in shortlex order is : where spaces (otherwise to be ignored) have been inserted just to show the strings being concatenated. Properties A real numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cahen's Constant
In mathematics, Cahen's constant is defined as the value of an infinite series of unit fractions with alternating signs: :C = \sum_^\infty \frac=\frac11 - \frac12 + \frac16 - \frac1 + \frac1 - \cdots\approx 0.643410546288... Here (s_i)_ denotes Sylvester's sequence, which is defined recursively by :\begin s_0~~~ = 2; \\ s_ = 1 + \prod_^i s_j \text i \geq 0. \end Combining these fractions in pairs leads to an alternative expansion of Cahen's constant as a series of positive unit fractions formed from the terms in even positions of Sylvester's sequence. This series for Cahen's constant forms its greedy Egyptian expansion: :C = \sum\frac=\frac12+\frac17+\frac1+\frac1+\cdots This constant is named after (also known for the Cahen–Mellin integral), who was the first to introduce it and prove its irrationality. Continued fraction expansion The majority of naturally occurring mathematical constants have no known simple patterns in their continued fraction expansions. Neverthele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apéry's Constant
In mathematics, Apéry's constant is the infinite sum of the reciprocals of the positive integers, cubed. That is, it is defined as the number : \begin \zeta(3) &= \sum_^\infty \frac \\ &= \lim_ \left(\frac + \frac + \cdots + \frac\right), \end where is the Riemann zeta function. It has an approximate value of : . It is named after Roger Apéry, who proved that it is an irrational number. Uses Apéry's constant arises naturally in a number of physical problems, including in the second- and third-order terms of the electron's gyromagnetic ratio using quantum electrodynamics. It also arises in the analysis of random minimum spanning trees and in conjunction with the gamma function when solving certain integrals involving exponential functions in a quotient, which appear occasionally in physics, for instance, when evaluating the two-dimensional case of the Debye model and the Stefan–Boltzmann law. The reciprocal of (0.8319073725807... ) is the probabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basel Problem
The Basel problem is a problem in mathematical analysis with relevance to number theory, concerning an infinite sum of inverse squares. It was first posed by Pietro Mengoli in 1650 and solved by Leonhard Euler in 1734, and read on 5 December 1735 in Russian Academy of Sciences#History, ''The Saint Petersburg Academy of Sciences''. Since the problem had withstood the attacks of the leading mathematicians of the day, Euler's solution brought him immediate fame when he was twenty-eight. Euler generalised the problem considerably, and his ideas were taken up more than a century later by Bernhard Riemann in his seminal 1859 paper "On the Number of Primes Less Than a Given Magnitude", in which he defined his Riemann zeta function, zeta function and proved its basic properties. The problem is named after the city of Basel, hometown of Euler as well as of the Bernoulli family who unsuccessfully attacked the problem. The Basel problem asks for the precise summation of the Multiplicative inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Series (mathematics)
In mathematics, a series is, roughly speaking, an addition of Infinity, infinitely many Addition#Terms, terms, one after the other. The study of series is a major part of calculus and its generalization, mathematical analysis. Series are used in most areas of mathematics, even for studying finite structures in combinatorics through generating functions. The mathematical properties of infinite series make them widely applicable in other quantitative disciplines such as physics, computer science, statistics and finance. Among the Ancient Greece, Ancient Greeks, the idea that a potential infinity, potentially infinite summation could produce a finite result was considered paradoxical, most famously in Zeno's paradoxes. Nonetheless, infinite series were applied practically by Ancient Greek mathematicians including Archimedes, for instance in the Quadrature of the Parabola, quadrature of the parabola. The mathematical side of Zeno's paradoxes was resolved using the concept of a limit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prouhet–Thue–Morse Constant
In mathematics, the Prouhet–Thue–Morse constant, named for , Axel Thue, and Marston Morse, is the number—denoted by —whose binary expansion 0.01101001100101101001011001101001... is given by the Prouhet–Thue–Morse sequence. That is, : \tau = \sum_^ \frac = 0.412454033640 \ldots where is the element of the Prouhet–Thue–Morse sequence. Other representations The Prouhet–Thue–Morse constant can also be expressed, without using , as an infinite product, : \tau = \frac\left -\prod_^\left(1-\frac\right)\right This formula is obtained by substituting ''x'' = 1/2 into generating series for : F(x) = \sum_^ (-1)^ x^n = \prod_^ ( 1 - x^ ) The continued fraction expansion of the constant is ; 2, 2, 2, 1, 4, 3, 5, 2, 1, 4, 2, 1, 5, 44, 1, 4, 1, 2, 4, 1, … Yann Bugeaud and Martine Queffélec showed that infinitely many partial quotients of this continued fraction are 4 or 5, and infinitely many partial quotients are greater than or equal to 50. Transcendence Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thue–Morse Sequence
In mathematics, the Thue–Morse or Prouhet–Thue–Morse sequence is the binary sequence (an infinite sequence of 0s and 1s) that can be obtained by starting with 0 and successively appending the Boolean complement of the sequence obtained thus far. It is sometimes called the fair share sequence because of its applications to fair division or parity sequence. The first few steps of this procedure yield the strings 0, 01, 0110, 01101001, 0110100110010110, and so on, which are the prefixes of the Thue–Morse sequence. The full sequence begins: :01101001100101101001011001101001.... The sequence is named after Axel Thue, Marston Morse and (in its extended form) Eugène Prouhet. Definition There are several equivalent ways of defining the Thue–Morse sequence. Direct definition To compute the ''n''th element ''tn'', write the number ''n'' in binary. If the number of ones in this binary expansion is odd then ''tn'' = 1, if even then ''tn'' = 0. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
