Hamilton's principle of stationary action lies at the foundation of theoretical physics and is applied in many other disciplines from pure mathematics to economics. Despite its utility, Hamilton's principle has a subtle pitfall that often goes unnoticed in physics: it is formulated as a boundary value problem in time but is used to derive equations of motion that are solved with initial data. T...

para o valor esperado de uma dada observável fı́sica A = A(p, q, t) representada pelo operador Â. As equações (1) e (2) são válidas desde que o potencial externo V varie vagarosamente dentro de um pacote de onda bem localizadoψPE (Pacote de Ehrenfest). Assim, de acordo com os livros-texto [1], as equações de Newton são obtidas como limite clássico da equação de Schrödinger. No entanto, Ballentin...

THE PHYSICS TEACHER ! Vol. 51, 2013 Teaching classical mechanics using smartphones Joel Chevrier, Université Joseph Fourier BP 53 38041 Grenoble Cedex 9 Laya Madani, Simon Ledenmat, and Ahmad Bsiesy, CIME Nanotech, Grenoble INP/UJF, BP 257, 38016 Grenoble Cedex 1 Jochen Kuhn and Patrik Vogt, Column Editors, Department of Physics/Didactics of Physics, University of Kaiserslautern, Erwin-Schrödin...

Using a group theoretical approach we derive an equation of motion for a mixed quantum-classical system. The quantum-classical bracket entering the equation preserves the Lie algebra structure of quantum and classical mechanics: The bracket is antisymmetric and satisfies the Jacobi identity, and, therefore, leads to a natural description of interaction between quantum and classical degrees of f...

From Classical to Quantum Mechanics: " How to translate physical ideas into mathematical language " Abstract In this paper, we investigate the connection between Classical and Quantum Mechanics by dividing Quantum Theory in two parts:-General Quantum Axiomatics (a system is described by a state in a Hilbert space, observables are self-adjoints operators and so on...)-Quantum Mechanics properly ...