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The concept of a dual norm arises in functional analysis, a branch of mathematics. Let be a normed space (or, in a special case, a Banach space) over a number field (i.e. or ) with norm . Then the ''dual'' (or ''conjugate'') ''normed'' space (another notation ) is defined as the set of all continuous linear functionals from into the base field . If is such a linear functional, then the ''dual norm'' of is defined by : With this norm, the dual space is also a normed space, and moreover a Banach space, since is always complete.〔http://www.seas.ucla.edu/~vandenbe/236C/lectures/proxop.pdf〕 == Examples == # Dual Norm of Vectors #:If ''p'', ''q'' ∈ satisfy , then the ℓ''p'' and ℓ''q'' norms are dual to each other. #:In particular the Euclidean norm is self-dual (). Similarly, the Schatten ''p''-norm on matrices is dual to the Schatten ''q''-norm. #:For , the dual norm is with positive definite. # Dual Norm of Matrices #:''Frobenius norm'' #:: #:Its dual norm is #:Dual norm 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「dual norm」の詳細全文を読む スポンサード リンク
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