翻訳と辞書
Words near each other
・ Complex coordinate space
・ Complex crater
・ Complex data type
・ Complex differential equation
・ Complex differential form
・ Complex dimension
・ Complex dynamics
・ Complex EP
・ Complex equality
・ Complex event processing
・ Complex fluid
・ Complex gain
・ Complex geodesic
・ Complex geometry
・ Complex group
Complex Hadamard matrix
・ Complex harmonic motion
・ Complex instruction set computing
・ Complex interdependence
・ Complex lamellar vector field
・ Complex Lie group
・ Complex line
・ Complex logarithm
・ Complex manifold
・ Complex measure
・ Complex metal hydride
・ Complex metallic alloys
・ Complex Mexican hat wavelet
・ Complex modulus
・ Complex multiplication


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

Complex Hadamard matrix : ウィキペディア英語版
Complex Hadamard matrix
A complex Hadamard matrix is any complex
N \times N matrix H satisfying two conditions:
*unimodularity (the modulus of each entry is unity): |H_|=1 j,k=1,2,\dots,N
*orthogonality: HH^ = N \; ,
where denotes the Hermitian transpose of ''H'' and is the identity matrix. The concept is a generalization of the Hadamard matrix. Note that any complex Hadamard matrix H can be made into a unitary matrix by multiplying it by \frac.
Complex Hadamard matrices arise in the study of operator algebras and the theory of quantum computation. Real Hadamard matrices and Butson-type Hadamard matrices form particular cases of complex Hadamard matrices.
Complex Hadamard matrices exist for any natural ''N'' (compare the real case, in which existence is not known for every ''N''). For instance the Fourier matrices
: ()_:= \exp(i(j - 1)(k - 1) / N )
j,k=1,2,\dots,N
belong to this class.
==Equivalency==
Two complex Hadamard matrices are called equivalent, written H_1 \simeq H_2, if there exist diagonal unitary matrices D_1, D_2 and permutation matrices P_1, P_2
such that
: H_1 = D_1 P_1 H_2 P_2 D_2.
Any complex Hadamard matrix is equivalent to a dephased Hadamard matrix, in which all elements in the first row and first column are equal to unity.
For N=2,3 and 5 all complex Hadamard matrices are equivalent to the Fourier matrix F_. For N=4 there exists
a continuous, one-parameter family of inequivalent complex Hadamard matrices,
: F_^(a):=
\begin 1 & 1 & 1 & 1 \\
1 & ie^ & -1 & -ie^ \\
1 & -1 & 1 &-1 \\
1 & -ie^& -1 & i e^
\end
a\in [0,\pi) .
For N=6 the following families of complex Hadamard matrices
are known:
* a single two-parameter family which includes F_6,
* a single one-parameter family D_6(t),
* a one-parameter orbit B_6(\theta), including the circulant Hadamard matrix C_6,
* a two-parameter orbit including the previous two examples X_6(\alpha),
* a one-parameter orbit M_6(x) of symmetric matrices,
* a two-parameter orbit including the previous example K_6(x,y),
* a three-parameter orbit including all the previous examples K_6(x,y,z),
* a further construction with four degrees of freedom, G_6, yielding other examples than K_6(x,y,z),
* a single point - one of the Butson-type Hadamard matrices, S_6 \in H(3,6).
It is not known, however, if this list is complete, but it is conjectured that K_6(x,y,z),G_6,S_6 is an exhaustive (but not necessarily irredundant) list of all complex Hadamard matrices of order 6.

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「Complex Hadamard 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.