|
In mathematics, the Remez inequality, discovered by the Soviet mathematician Evgeny Yakovlevich Remez , gives a bound on the sup norms of certain polynomials, the bound being attained by the Chebyshev polynomials. ==The inequality== Let σ be an arbitrary fixed positive number. Define the class of polynomials π''n''(σ) to be those polynomials ''p'' of the ''n''th degree for which : on some set of measure ≥ 2 contained in the closed interval (). Then the Remez inequality states that : where ''T''''n''(''x'') is the Chebyshev polynomial of degree ''n'', and the supremum norm is taken over the interval (). Observe that ''T''''n'' is increasing on , hence : The R.i., combined with an estimate on Chebyshev polynomials, implies the following corollary: If ''J'' ⊂ R is a finite interval, and ''E'' ⊂ ''J'' is an arbitrary measurable set, then : for any polynomial ''p'' of degree ''n''. 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「Remez inequality」の詳細全文を読む スポンサード リンク
|