Abstract
The Rayleigh-Ritz minimization principle is generalized to ensembles of unequally weighted states. Given the M lowest eigenvalues E1E2...EM of a Hamiltonian H, and given M real numbers w1w2...wM>0, an upper bound for the weighted sum w1E1 +w2E2+...+wMEM is established. Particular cases are the ground-state Rayleigh-Ritz principle (M=1) and the variational principle for equiensembles (w1=w2=...=wM). Applications of the generalized principle are discussed.
Original language | English |
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Pages (from-to) | 2805-2808 |
Number of pages | 4 |
Journal | Physical Review A |
Volume | 37 |
Issue number | 8 |
DOIs | |
State | Published - 1988 |
Externally published | Yes |