Linear Time-Dependent Invariants for Scalar Fields and Noether's Theorem

The infinite number of time-dependent linear in field and conjugated momenta invariants is derived for the scalar field using the Noether's theorem procedure.Comment: LaTeX, 6 pages, preprint of Instituto de Ciencias Nucleares, UNAM, Departamento de F\ii sica and Matem\'aticas Aplicadas, M\'exico D. F. , M\'exico No. 04 (1994

Squeezing in a 2-D generalized oscillator

A two-dimensional generalized oscillator with time-dependent parameters is considered to study the two-mode squeezing phenomena. Specific choices of the parameters are used to determine the dispersion matrix and analytic expressions, in terms of standard hermite polynomials, of the wavefunctions and photon distributions. (to be publish in the Third Workshop on Squeezed States and Uncertainty Relations, Baltimore, USA, (August 1993))Comment: LaTeX, 5 pages, preprint of Instituto de Ciencias Nucleares, UNAM Departamento de F\ii sica and Matem\'aticas Aplicadas, No. 02 (1994