I recently read the paper "On Spectral Clustering: Analysis and an Algorithm" by Ng et al.
Much of the paper centers on Theorem 2 and equation 8. To me, it appears there is no given or referenced proof of this Theorem. I am hoping that someone can point me in the right direction to understanding the derivation of this result.
Perhaps a longer version of the paper (I am unable to find one so far), or is the result 'obvious' and I am missing something? Any help is greatly appreciated!