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Böttcher's Equation
Böttcher's equation, named after Lucjan Böttcher, is the functional equation ::F(h(z)) = (F(z))^n where * is a given analytic function with a superattracting fixed point of order at , (that is, h(z)=a+c(z-a)^n+O((z-a)^) ~, in a neighbourhood of ), with ''n'' ≥ 2 * is a sought function. The logarithm of this functional equation amounts to Schröder's equation. Solution Solution of functional equation is a function in implicit form. Lucian Emil Böttcher sketched a proof in 1904 on the existence of solution: an analytic function ''F'' in a neighborhood of the fixed point ''a'', such that: :F(a)= 0 This solution is sometimes called: * the Böttcher coordinate * the Böttcher function * the Boettcher map. The complete proof was published by Joseph Ritt in 1920, who was unaware of the original formulation. Böttcher's coordinate (the logarithm of the Schröder function) conjugates in a neighbourhood of the fixed point to the function . An espec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lucjan Böttcher
{{Infobox scientist , name = Lucjan Emil Böttcher , native_name = , native_name_lang = , image = , image_size = , alt = , caption = , birth_date = , birth_place = Warsaw, Congress Poland, Russian Empire , death_date = , death_place = Lwów, Poland , resting_place = , resting_place_coordinates = , other_names = , residence = , citizenship = Poland , nationality = Polish , fields = , workplaces = , alma_mater = Lwów Polytechnic School, University of Leipzig , thesis_title = Beiträge zu der Theorie der Iterationsrechnung , thesis_url = , thesis_year = 1898 , doctoral_advisor = Sophus Lie , academic_advisors = , doctoral_students = , notable_students = , known_for = Böttcher's equation , author_abbrev_bot = , author_abbrev_zoo = , influences = , influence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aequationes Mathematicae
''Aequationes Mathematicae'' is a mathematical journal. It is primarily devoted to functional equations, but also publishes papers in dynamical systems, combinatorics, and geometry. As well as publishing regular journal submissions on these topics, it also regularly reports on international symposia on functional equations and produces bibliographies on the subject. János Aczél founded the journal in 1968 at the University of Waterloo, in part because of the long publication delays of up to four years in other journals at the time of its founding. It is currently published by Springer Science+Business Media, with Zsolt Páles of the University of Debrecen as its editor in chief. János Aczél remains its honorary editor in chief. it was listed as a second-quartile mathematics journal by SCImago Journal Rank The SCImago Journal Rank (SJR) indicator is a measure of the prestige of scholarly journals that accounts for both the number of citations received by a journal and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrian Douady
Adrien Douady (; 25 September 1935 – 2 November 2006) was a French mathematician. Douady was a student of Henri Cartan at the École normale supérieure, and initially worked in homological algebra. His thesis concerned deformations of complex analytic spaces. Subsequently, he became more interested in the work of Pierre Fatou and Gaston Julia and made significant contributions to the fields of analytic geometry and dynamical systems. Together with his former student John H. Hubbard, he launched a new subject, and a new school, studying properties of iterated quadratic complex mappings. They made important mathematical contributions in this field of complex dynamics, including a study of the Mandelbrot set. One of their most fundamental results is that the Mandelbrot set is connected; perhaps most important is their theory of renormalization of (polynomial-like) maps. The Douady rabbit, a quadratic filled Julia set, is named after him. Douady taught at the University of N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Fatou
Pierre Joseph Louis Fatou (28 February 1878 – 9 August 1929) was a French mathematician and astronomer. He is known for major contributions to several branches of analysis. The Fatou lemma and the Fatou set are named after him. Biography Pierre Fatou's parents were Prosper Ernest Fatou (1832-1891) and Louise Eulalie Courbet (1844-1911), both of whom were in the military. Pierre's family would have liked for him to enter the military as well, but his health was not sufficiently good for him to pursue a military career. Fatou entered the École Normale Supérieure in Paris in 1898 to study mathematics and graduated in 1901 when he was appointed an intern (''stagiaire'') in the Paris Observatory. Fatou was promoted to assistant astronomer in 1904 and to astronomer (''astronome titulaire'') in 1928. He worked in this observatory until his death. Fatou was awarded the Becquerel prize in 1918; he was a knight of the Legion of Honour (1923). He was the president of the French m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Variable
Complex analysis, traditionally known as the theory of functions of a complex variable, is the branch of mathematical analysis that investigates functions of complex numbers. It is helpful in many branches of mathematics, including algebraic geometry, number theory, analytic combinatorics, applied mathematics; as well as in physics, including the branches of hydrodynamics, thermodynamics, and particularly quantum mechanics. By extension, use of complex analysis also has applications in engineering fields such as nuclear, aerospace, mechanical and electrical engineering. As a differentiable function of a complex variable is equal to its Taylor series (that is, it is analytic), complex analysis is particularly concerned with analytic functions of a complex variable (that is, holomorphic functions). History Complex analysis is one of the classical branches in mathematics, with roots in the 18th century and just prior. Important mathematicians associated with complex n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polynomial
In mathematics, a polynomial is an expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication, and positive-integer powers of variables. An example of a polynomial of a single indeterminate is . An example with three indeterminates is . Polynomials appear in many areas of mathematics and science. For example, they are used to form polynomial equations, which encode a wide range of problems, from elementary word problems to complicated scientific problems; they are used to define polynomial functions, which appear in settings ranging from basic chemistry and physics to economics and social science; they are used in calculus and numerical analysis to approximate other functions. In advanced mathematics, polynomials are used to construct polynomial rings and algebraic varieties, which are central concepts in algebra and algebraic geometry. Etymology The word ''polynomial'' joins tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iteration
Iteration is the repetition of a process in order to generate a (possibly unbounded) sequence of outcomes. Each repetition of the process is a single iteration, and the outcome of each iteration is then the starting point of the next iteration. In mathematics and computer science, iteration (along with the related technique of recursion) is a standard element of algorithms. Mathematics In mathematics, iteration may refer to the process of iterating a function, i.e. applying a function repeatedly, using the output from one iteration as the input to the next. Iteration of apparently simple functions can produce complex behaviors and difficult problems – for examples, see the Collatz conjecture and juggler sequences. Another use of iteration in mathematics is in iterative methods which are used to produce approximate numerical solutions to certain mathematical problems. Newton's method is an example of an iterative method. Manual calculation of a number's square root is a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holomorphic Dynamics
Complex dynamics is the study of dynamical systems defined by iteration of functions on complex number spaces. Complex analytic dynamics is the study of the dynamics of specifically analytic functions. Techniques *General **Montel's theorem **Poincaré metric **Schwarz lemma **Riemann mapping theorem **Carathéodory's theorem (conformal mapping) ** Böttcher's equation *Combinatorial ** Hubbard trees ** Spider algorithm ** Tuning ** Laminations ** Devil's Staircase algorithm (Cantor function) **Orbit portraits ** Yoccoz puzzles Parts * Holomorphic dynamics (dynamics of holomorphic functions) ** in one complex variable ** in several complex variables * Conformal dynamics unites holomorphic dynamics in one complex variable with differentiable dynamics in one real variable. See also *Arithmetic dynamics *Chaos theory *Complex analysis *Complex quadratic polynomial *Fatou set *Infinite compositions of analytic functions *Julia set *Mandelbrot set *Symbolic dynamics Notes Refer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chebyshev Polynomials
The Chebyshev polynomials are two sequences of polynomials related to the trigonometric functions, cosine and sine functions, notated as T_n(x) and U_n(x). They can be defined in several equivalent ways, one of which starts with trigonometric functions: The Chebyshev polynomials of the first kind T_n are defined by : T_n(\cos \theta) = \cos(n\theta). Similarly, the Chebyshev polynomials of the second kind U_n are defined by : U_n(\cos \theta) \sin \theta = \sin\big((n + 1)\theta\big). That these expressions define polynomials in \cos\theta may not be obvious at first sight, but follows by rewriting \cos(n\theta) and \sin\big((n+1)\theta\big) using de Moivre's formula or by using the List of trigonometric identities#Angle sum and difference identities, angle sum formulas for \cos and \sin repeatedly. For example, the List of trigonometric identities#Double-angle formulae, double angle formulas, which follow directly from the angle sum formulas, may be used to obtain T_2(\cos\t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Ritt
Joseph Fels Ritt (August 23, 1893 – January 5, 1951) was an American mathematician at Columbia University in the early 20th century. He was born and died in New York. After beginning his undergraduate studies at City College of New York, Ritt received his B.A. from George Washington University in 1913. He then earned a doctorate in mathematics from Columbia University in 1917 under the supervision of Edward Kasner. After doing calculations for the war effort in World War I, he joined the Columbia faculty in 1921. He served as department chair from 1942 to 1945, and in 1945 became the Davies Professor of Mathematics.. In 1932, George Washington University honored him with a Doctorate in Science,. and in 1933 he was elected to join the United States National Academy of Sciences. He has 463 academic descendants listed in the Mathematics Genealogy Project, mostly through his student Ellis Kolchin. Ritt was an Invited Speaker with talk ''Elementary functions and their inverses'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Equation
In mathematics, a functional equation is, in the broadest meaning, an equation in which one or several functions appear as unknowns. So, differential equations and integral equations are functional equations. However, a more restricted meaning is often used, where a ''functional equation'' is an equation that relates several values of the same function. For example, the logarithm functions are essentially characterized by the ''logarithmic functional equation'' \log(xy)=\log(x) + \log(y). If the domain of the unknown function is supposed to be the natural numbers, the function is generally viewed as a sequence, and, in this case, a functional equation (in the narrower meaning) is called a recurrence relation. Thus the term ''functional equation'' is used mainly for real functions and complex functions. Moreover a smoothness condition is often assumed for the solutions, since without such a condition, most functional equations have very irregular solutions. For example, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Ray
An external ray is a curve that runs from infinity toward a Julia or Mandelbrot set. Although this curve is only rarely a half-line (ray) it is called a ray because it is an image of a ray. External rays are used in complex analysis, particularly in complex dynamics and geometric function theory. History External rays were introduced in Douady and Hubbard's study of the Mandelbrot set Types Criteria for classification : * plane : parameter or dynamic * map * bifurcation of dynamic rays * Stretching * landing plane External rays of (connected) Julia sets on dynamical plane are often called dynamic rays. External rays of the Mandelbrot set (and similar one-dimensional connectedness loci) on parameter plane are called parameter rays. bifurcation Dynamic ray can be: * bifurcated = branched = broken * smooth = unbranched = unbroken When the filled Julia set is connected, there are no branching external rays. When the Julia set is not connected then some external ray ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
