This text shows how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mechanics, and quantum mechanics; field equations; eigenvalue problems; and scattering theory. 1966 edition. Unabridged republication of the edition published by Interscience Publishers, John Wiley & Sons, New York, 1966.
Variational Methods in Optimization by Donald R. Smith Highly readable text elucidates applications of the chain rule of differentiation, integration by parts, parametric curves, line integrals, double integrals, and elementary differential equations. 1974 edition.
Variational Analysis: Critical Extremals and Sturmian Extensions by Marston Morse This text presents extended separation, comparison, and oscillation theorems that replace classical analysis. Its analysis of related quadratic functionals shows how critical extremals can substitute for minimizing extremals. 1973 edition.
Gauge Theory and Variational Principles by David Bleecker Covers principal fiber bundles and connections; curvature; particle fields, Lagrangians, and gauge invariance; inhomogeneous field equations; free Dirac electron fields; calculus on frame bundle; and unification of gauge fields and gravitation. 1981 edition