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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Lower bounds to energy eigenvalues in perturbation theory ground state, studying lower bounds to ground state energies of helium-like ions
Low bounds to energy eigenvalues in quantum theory problems by partitioning technique for positive perturbation
General perturbations theory applications to spacecraft guidance, flight mechanics, and trajectory optimization
Adiabatic perturbation theory in celestial mechanics
Canonical perturbation theory formulation applied to Poincare-von Zeipel method
Evaluation of upper bound to energy eigenvalues in Schroedinger perturbation theory, utilizing theory of inhomogeneous equations
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A diagnostic for perturbation theory calculations, S(sub 2), is defined and numerical results are compared to the established T(sub 1) diagnostic from coupled-cluster theory. S(sub 2) is the lowest order non-zero contribution to a perturbation expansion of T(sub 1). S(sub 2) is a reasonable estimate of the importance of non-dynamical electron correlation, although not as reliable as T(sub 1). S(sub 2) values less than or equal to 0.012 suggest that low orders of perturbation theory should yield reasonable results; S(sub 2) values between 0.012-0.015 suggest that caution is required in interpreting results from low orders of perturbation theory; S(sub 2) values greater than or equal to 0.015 indicate that low orders of perturbation theory are not reliable for accurate results. Although not required mathematically, S(sub 2) is always less than T(sub 1) for the examples studied here.
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Partitioning perturbation theory for electron exchange problems, generalizing Hirschfelder- Silbey formalism
Rayleigh-Schroeder perturbation theory - degenerate and non-degenerate states - quantum chemistry - other perturbation equations
Perturbation theory applied to laguerre functions
Perturbation theory in molecular quantum physics using variational principles
Perturbation theory used in quantum mechanics to determine molecular energy and properties
Perturbation theory for exchange forces using Brillouin and Schroedinger equations
Variational methods and degenerate perturbation theory
Three-dimensional guidance scheme for decending from lunar orbit to hovering position based on linear theory of perturbations
Perturbation theories of intermolecular forces compared for connections of equivalency