The main goal of this paper is to extend the so-called Dirac-Frenkel variational principle in the framework of tensor Banach spaces. To this end we observe that a tensor product of normed spaces can be described as a union of disjoint connected components. Then we show that each of these ...
We reformulate the Dirac-Frenkel approximation principle in terms of reduced density matrices, and apply it to fermionic and bosonic many-body systems. We obtain the Bogoliubov-de-Gennes and Hartree-Fock-Bogoliubov equations, respectively. While we do not prove quantitative error estimates, our ...
variational techniques/ Dirac-Frenkel/McLachlan variational principletime-dependent parameter setequations of motionerror estimate/ A0365C Formalism in quantum theory A0230 Function theory, analysisThe Dirac–Frenkel/McLachlan variational principle (DFMVP) is re-derived using a general and strict formalism ...
Variation of parametersTime dependent HamiltonianDiffusionThe time dependent variation of parameters solution to the time dependent Schrdinger equation pioneered by Dirac, Frenkel, and McLachlan is described in terms useful for immediate application to complex time dependent problems in magnetic resonance. A...