{"product_id":"schwinger-s-quantum-action-principle-book-kimball-a-milton-9783319201276","title":"Schwinger's Quantum Action Principle","description":"Starting from the earlier notions of stationary action principles, these tutorial notes shows how Schwinger's Quantum Action Principle descended from Dirac's formulation, which independently led Feynman to his path-integral formulation of quantum mechanics. Part I brings out in more detail the connection between the two formulations, and applications are discussed. Then, the Keldysh-Schwinger time-cycle method of extracting matrix elements is described. Part I will discuss the variational formulation of quantum electrodynamics and the development of source theory.","brand":"WoB","offers":[{"title":"- \/ - \/ -","offer_id":51142616645905,"sku":"","price":0.0,"currency_code":"EUR","in_stock":true},{"title":"US \/ NEW \/ INGRAM","offer_id":51142619595025,"sku":"NIN9783319201276","price":0.0,"currency_code":"EUR","in_stock":false},{"title":"GB \/ NEW \/ INGRAM","offer_id":52148969537809,"sku":"NLS9783319201276","price":0.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0784\/4072\/6801\/files\/3319201271.jpg?v=1750933832","url":"https:\/\/www.worldofbooks.com\/de-de\/products\/schwinger-s-quantum-action-principle-buch-kimball-a-milton-9783319201276","provider":"World of Books ","version":"1.0","type":"link"}