symplectically covariant quantum-mechanical uncertainty relation more accurate than previously known ones is derived for multidimensional systems. It is shown that the quantum-mechanical description of a linear Hamiltonian system in terms of squeezed states is completely equivalent to its description in terms of a phase-space distribution function. A new approach to the semiclassical limit is proposed, based on the use of squeezed states. By analyzing explicit formulas for squeezed states, a semiclassical asymptotic form of the solution to the Cauchy problem for a multidimensional Schrodinger equation is found in the limit of h_ú0. The behavior of the semiclassical solution in the neighborhood of a caustic is analyzed in the one-dimensional case, and the phase shift across the caustic is determined. General properties and examples of squeezed states are discussed that point to the fundamental importance of squeezed states for developing a nonrelativistic quantum-mechanical description of a system of charged particles in an electromagnetic field in the dipole approximation.
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