翻訳と辞書
Words near each other
・ Ski jumping at the 1990 Asian Winter Games
・ Skew heap
・ Skew It on the Bar-B
・ Skew lattice
・ Skew lines
・ Skew normal distribution
・ Skew partition
・ Skew Peak
・ Skew polygon
・ Skew Siskin
・ Skew Siskin (album)
・ Skew-Hamiltonian matrix
・ Skew-Hermitian
・ Skew-Hermitian matrix
・ Skew-symmetric graph
Skew-symmetric matrix
・ Skew-T log-P diagram
・ Skewarkey Primitive Baptist Church
・ Skewb
・ Skewb Diamond
・ Skewb Ultimate
・ Skewbald
・ Skewbald Horde
・ Skewbald/Grand Union (EP)
・ Skewball
・ Skewed generalized t distribution
・ Skewed Visions
・ Skewed X-inactivation
・ Skewen
・ Skewen railway station


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

Skew-symmetric matrix : ウィキペディア英語版
Skew-symmetric matrix

In mathematics, and in particular linear algebra, a skew-symmetric (or antisymmetric or antimetric) matrix is a square matrix ''A'' whose transpose is also its negative; that is, it satisfies the condition If the entry in the and is ''aij'', i.e. then the skew symmetric condition is For example, the following matrix is skew-symmetric:
:\begin
0 & 2 & -1 \\
-2 & 0 & -4 \\
1 & 4 & 0\end.
== Properties ==

We assume that the underlying field is not of characteristic 2: that is, that where 1 denotes the multiplicative identity and 0 the additive identity of the given field. Otherwise, a skew-symmetric matrix is just the same thing as a symmetric matrix.
Sums and scalar multiples of skew-symmetric matrices are again skew-symmetric. Hence, the skew-symmetric matrices form a vector space. Its dimension is ''n''(''n''−1)/2.
Let Mat''n'' denote the space of matrices. A skew-symmetric matrix is determined by ''n''(''n'' − 1)/2 scalars (the number of entries above the main diagonal); a symmetric matrix is determined by ''n''(''n'' + 1)/2 scalars (the number of entries on or above the main diagonal). Let Skew''n'' denote the space of skew-symmetric matrices and Sym''n'' denote the space of symmetric matrices. If then
: A = \frac(A - A^(A + A^,
: \mbox_n = \mbox_n \oplus \mbox_n,
where ⊕ denotes the direct sum.
Denote with \langle \cdot,\cdot \rangle the standard inner product on R''n''. The real ''n''-by-''n'' matrix ''A'' is skew-symmetric if and only if
:\langle Ax,y \rangle = - \langle x, Ay\rangle \quad \forall x,y\in\Bbb^n.
This is also equivalent to \langle x,Ax \rangle = 0 for all ''x'' (one implication being obvious, the other a plain consequence of \langle x+y, A(x+y)\rangle =0 for all x and y).
Since this definition is independent of the choice of basis, skew-symmetry is a property that depends only on the linear operator A and a choice of inner product.
All main diagonal entries of a skew-symmetric matrix must be zero, so the trace is zero. If is skew-symmetric, ; hence
3x3 skew symmetric matrices can be used to represent cross products as matrix multiplications.

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「Skew-symmetric matrix」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.