Focusing on applications most relevant to modern physics, this text surveys variational principles and examines their relationship to dynamics and quantum theory. It stresses the history and theory of these mathematical concepts rather than their mechanics, providing many insights into the development of quantum mechanics in a remarkably lucid, compact form. Professional physicists and mathematicians, as well as advanced students with a strong mathematical background, will find it highly stimulating. After summarizing the historical background from Pythagoras to Francis Bacon, the text covers Fermat's principle of least time, the principle of least action of Maupertuis, the development of this principle by Euler and Lagrange, and the equations of Lagrange and Hamilton. After this general treatment of variational principles, the authors proceed to derive Hamilton's principle, the Hamilton-Jacobi equation, and Hamilton's canonical equations. An investigation of electrodynamics in Hamiltonian form follows, along with an overview of variational principles in classical dynamics. The text then analyzes its most significant the relation between variational principles and wave mechanics, and the principles of Feynman and Schwinger in quantum mechanics. Two concluding chapters extend the discussion to hydrodynamics and natural philosophy.
Yet another top quality little book on Physics from Dover.
Want to see how the variational principles and the principle of least action appears in most important physical theories (quantum mechanics, hamiltonian mechanics, fluid mechanics...) ?
Probably a great, concise discussion of variational principles and their history. Mandelstam and Yourgrau start with Hero's analysis of light, and then jump to Fermat.
One of the great positives this book has: it contains multiple "sanity checks", deriving the same result from a different starting point.
It's a little weak on discussing gauge symmetries, but one could easily consult Henneaux and Teitelboim's Quantization of Gauge Systems for sordid details of that...