As we know that the Ky Fan k Norm is the sum of k-th largest singular values.
On the other hand, the trace of a matrix is the sum of its eigenvalues.
For a N by N symmetric matrix $M$, its Ky Fan N-Norm is equal to the trace of $M$.
Yet how about the matrix $M$ is square but not symmetric?
Is there any relation between the trace and the Ky Fan $N$ norm?