Normal Matrix

From GM-RKB
Jump to navigation Jump to search

A Normal Matrix is a Complex Square Matrix, [math]\displaystyle{ A }[/math] where [math]\displaystyle{ A^*A=AA^* }[/math] where [math]\displaystyle{ A^* }[/math] is the conjugate transpose of [math]\displaystyle{ A^* }[/math].



References

2015

  • (Wikipedia, 2015) ⇒ http://en.wikipedia.org/wiki/normal_matrix Retrieved:2015-2-16.
    • In mathematics, a complex square matrix is normal if : [math]\displaystyle{ A^*A=AA^* }[/math] where A∗ is the conjugate transpose of A. That is, a matrix is normal if it commutes with its conjugate transpose.

      That is, a matrix is normal if it commutes with its conjugate transpose.

      A real square matrix satisfies A∗ AT, and is therefore normal if ATA AAT.

      Normality is a convenient test for diagonalizability: a matrix is normal if and only if it is unitarily similar to a diagonal matrix, and therefore any matrix satisfying the equation A∗A AA∗ is diagonalizable.

      The concept of normal matrices can be extended to normal operators on infinite dimensional Hilbert spaces and to normal elements in C*-algebras. As in the matrix case, normality means commutativity is preserved, to the extent possible, in the noncommutative setting. This makes normal operators, and normal elements of C*-algebras, more amenable to analysis.