The last of the Ky Fan norms, the sum of all singular values, is the trace norm (also known as the 'nuclear norm'), defined by (the eigenvalues of are the squares of the singular values).
The last of the Ky Fan norms, the sum of all singular values, is the trace norm (also known as the 'nuclear norm') defined by (the eigenvalues of are the squar,es of the singular values).