the diagonalization of a normal matrix by a unitary transformation.
Examples of diagonalization
diagonalization
In 2008, David Wolpert used Cantor diagonalization to disprove Laplace's demon.
From the guardian.co.uk
Another approach is numerical matrix diagonalization.
From the en.wikipedia.org
The formal machinery of this proof is wholly elementary except for the diagonalization that the diagonal lemma requires.
From the en.wikipedia.org
This concept of diagonalization is relatively straightforward for operators on finite-dimensional spaces, but requires some modification for operators on infinite-dimensional spaces.
From the en.wikipedia.org
Also, diagonalization was originally used to show the existence of arbitrarily hard complexity classes and played a key role in early attempts to prove P does not equal NP.
From the en.wikipedia.org
More examples
Changing a square matrix to diagonal form (with all non-zero elements on the principal diagonal); "the diagonalization of a normal matrix by a unitary transformation"