翻訳と辞書
Words near each other
・ "O" Is for Outlaw
・ "O"-Jung.Ban.Hap.
・ "Ode-to-Napoleon" hexachord
・ "Oh Yeah!" Live
・ "Our Contemporary" regional art exhibition (Leningrad, 1975)
・ "P" Is for Peril
・ "Pimpernel" Smith
・ "Polish death camp" controversy
・ "Pro knigi" ("About books")
・ "Prosopa" Greek Television Awards
・ "Pussy Cats" Starring the Walkmen
・ "Q" Is for Quarry
・ "R" Is for Ricochet
・ "R" The King (2016 film)
・ "Rags" Ragland
・ ! (album)
・ ! (disambiguation)
・ !!
・ !!!
・ !!! (album)
・ !!Destroy-Oh-Boy!!
・ !Action Pact!
・ !Arriba! La Pachanga
・ !Hero
・ !Hero (album)
・ !Kung language
・ !Oka Tokat
・ !PAUS3
・ !T.O.O.H.!
・ !Women Art Revolution


Dictionary Lists
翻訳と辞書 辞書検索 [ 開発暫定版 ]
スポンサード リンク

binomial type : ウィキペディア英語版
binomial type

In mathematics, a polynomial sequence, i.e., a sequence of polynomials indexed by in which the index of each polynomial equals its degree, is said to be of binomial type if it satisfies the sequence of identities
:p_n(x+y)=\sum_^n\, p_k(x)\, p_(y).
Many such sequences exist. The set of all such sequences forms a Lie group under the operation of umbral composition, explained below. Every sequence of binomial type may be expressed in terms of the Bell polynomials. Every sequence of binomial type is a Sheffer sequence (but most Sheffer sequences are not of binomial type). Polynomial sequences put on firm footing the vague 19th century notions of umbral calculus.
==Examples==

* In consequence of this definition the binomial theorem can be stated by saying that the sequence is of binomial type.
* The sequence of "lower factorials" is defined by
::(x)_n=x(x-1)(x-2)\cdot\cdots\cdot(x-n+1).
:(In the theory of special functions, this same notation denotes upper factorials, but this present usage is universal among combinatorialists.) The product is understood to be 1 if ''n'' = 0, since it is in that case an empty product. This polynomial sequence is of binomial type.
* Similarly the "upper factorials"
::x^=x(x+1)(x+2)\cdot\cdots\cdot(x+n-1)
:are a polynomial sequence of binomial type.
* The Abel polynomials
::p_n(x)=x(x-an)^ \,
:are a polynomial sequence of binomial type.
* The Touchard polynomials
::p_n(x)=\sum_^n S(n,k)x^k
:where ''S''(''n'', ''k'') is the number of partitions of a set of size ''n'' into ''k'' disjoint non-empty subsets, is a polynomial sequence of binomial type. Eric Temple Bell called these the "exponential polynomials" and that term is also sometimes seen in the literature. The coefficients ''S''(''n'', ''k'' ) are "Stirling numbers of the second kind". This sequence has a curious connection with the Poisson distribution: If ''X'' is a random variable with a Poisson distribution with expected value λ then E(''X''''n'') = ''p''''n''(λ). In particular, when λ = 1, we see that the ''n''th moment of the Poisson distribution with expected value 1 is the number of partitions of a set of size ''n'', called the ''n''th Bell number. This fact about the ''n''th moment of that particular Poisson distribution is "Dobinski's formula".

抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)
ウィキペディアで「binomial type」の詳細全文を読む



スポンサード リンク
翻訳と辞書 : 翻訳のためのインターネットリソース

Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.