The Complex Spectral Theorem (via The Unapologetic Mathematician)

i have been spending the whole night studying this shit………. god bless

We're now ready to characterize those transformations on complex vector spaces which have a diagonal matrix with respect to some orthonormal basis. First of all, such a transformation must be normal. If we have a diagonal matrix we can find the matrix of the adjoint by taking its conjugate transpose, and this will again be diagonal. Since any two diagonal matrices commute, the transformation must commute with its adjoint, and is therefore normal. … Read More

via The Unapologetic Mathematician