Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields · 1974 · 1.4K citations · 14 references
Natural SciencesMathematicsPhysicsDifferential EquationsMathematical PhysicsOperator TheoryPartial Differential EquationsVariational FormulationVariational PrinciplesWeak FormulationDynamical Symmetry BreakingEffective ActionNonlinear Differential-algebraic EquationsNonlinear Variational FormulationOperatorsParametric VariationsVariational Methods In Partial Differential EquationsVariational Problems
An effective action and potential for composite operators is obtained. The formalism is used to analyze, by variational techniques, dynamical symmetry breaking and coherent solutions to field theory. A Rayleigh-Ritz procedure is introduced which replaces arbitrary variations with parametric variations. Previously unsolved nonlinear equations become, in the Rayleigh-Ritz approximation, solvable algebraic equations.
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Ground-State Energy of a Many-Fermion System. II
J. M. Luttinger, John Ward · Physical Review · 1960 · 1.7K citations