Before revision:  We show that the problem can be formulated as the variational optimization of a single scalar functional , a generalized matrix Rayleigh quotient (GMRQ), which measures the ability of a rank-m projection operator to capture the slow dynamics of the system.
After revision:  We show that the problem can be formulated as the variational optimization of a single scalar functional , a generalized matrix Rayleigh quotient (GMRQ), which measures the ability of a rank-m projection operator to capture the slow subspace of the system.