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

Jacobi triple product identity : ウィキペディア英語版
Jacobi triple product
In mathematics, the Jacobi triple product is the mathematical identity:
:\prod_^\infty
\left( 1 - x^\right)
\left( 1 + x^ y^2\right)
\left( 1 +\frac\right)
= \sum_^\infty x^ y^,

for complex numbers ''x'' and ''y'', with |''x''| < 1 and ''y'' ≠ 0.
It was introduced by in his work ''Fundamenta Nova Theoriae Functionum Ellipticarum''.
The Jacobi triple product identity is the Macdonald identity for the affine root system of type ''A''1, and is the Weyl denominator formula for the corresponding affine Kac–Moody algebra.
== Properties ==

The basis of Jacobi's proof relies on Euler's pentagonal number theorem, which is itself a specific case of the Jacobi Triple Product Identity.
Let x=q\sqrt q and y^2=-\sqrt. Then we have
:\phi(q) = \prod_^\infty \left(1-q^m \right) =
\sum_^\infty (-1)^n q^}.\,
The Jacobi Triple Product also allows the Jacobi theta function to be written as an infinite product as follows:
Let x=e^ and y=e^.
Then the Jacobi theta function
:
\vartheta(z; \tau) = \sum_^\infty e^} n z}

can be written in the form
:\sum_^\infty y^x^.
Using the Jacobi Triple Product Identity we can then write the theta function as the product
:\vartheta(z; \tau) = \prod_^\infty
\left( 1 - e^\right)
\left(1 + e^} z}\right )
\left(1 + e^} z}\right ).

There are many different notations used to express the Jacobi triple product. It takes on a concise form when expressed in terms of q-Pochhammer symbols:
:\sum_^\infty q^}z^n =
(q;q)_\infty \; \left(-\frac;q\right)_\infty \; (-zq;q)_\infty,
where (a;q)_\infty is the infinite ''q''-Pochhammer symbol.
It enjoys a particularly elegant form when expressed in terms of the Ramanujan theta function. For |ab|<1 it can be written as
:\sum_^\infty a^} \; b^} = (-a; ab)_\infty \;(-b; ab)_\infty \;(ab;ab)_\infty.

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「Jacobi triple product」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.