翻訳と辞書
Words near each other
・ Dinhata I (community development block)
・ Dinhata II (community development block)
・ Dinhata subdivision
・ Dinheirosaurus
・ Dinhing Dapita Sadya
・ Dinho Chingunji
・ Dini
・ Dini Beyk
・ Dini Cabinet
・ Dini continuity
・ Dini criterion
・ Dini Daniel
・ Dini derivative
・ Dini Dimakos
・ Dini Petty
Dini test
・ Dini Ya Msambwa
・ Dini's Lucky Club
・ Dini's surface
・ Dini's theorem
・ DinI-like protein family
・ Dinia
・ Dinia (moth)
・ Dinia eagrus
・ Dinia mena
・ Dinia subapicalis
・ Dinic
・ Dinic's algorithm
・ Dinichthyloidea
・ Dinichthys


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

Dini test : ウィキペディア英語版
Dini test
In mathematics, the Dini and Dini-Lipschitz tests are highly precise tests that can be used to prove that the Fourier series of a function converges at a given point. These tests are named after Ulisse Dini and Rudolf Lipschitz.
== Definition ==

Let ''f'' be a function on (), let ''t'' be some point and let δ be a positive number. We define the local modulus of continuity at the point ''t'' by
:\left.\right.\omega_f(\delta;t)=\max_ |f(t)-f(t+\varepsilon)|
Notice that we consider here ''f'' to be a periodic function, e.g. if ''t'' = 0 and ε is negative then we ''define'' ''f''(ε) = ''f''(2π + ε).
The global modulus of continuity (or simply the modulus of continuity) is defined by
:\left.\right.\omega_f(\delta) = \max_t \omega_f(\delta;t)
With these definitions we may state the main results
''Theorem (Dini's test): Assume a function f satisfies at a point t that''
:\int_0^\pi \frac\omega_f(\delta;t)\,d\delta < \infty.
''Then the Fourier series of f converges at t to f(t).''
For example, the theorem holds with \omega_f=\log^(\delta^) but does not hold with \log^(\delta^).
''Theorem (the Dini-Lipschitz test): Assume a function f satisfies''
:\omega_f(\delta)=o\left(\log\frac\right)^.
''Then the Fourier series of f converges uniformly to f.''
In particular, any function of a Hölder class satisfies the Dini-Lipschitz test.

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「Dini test」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.