GAUGE COVARIANT CONSTRUCTION OF THE COHERENT STATES FOR A TIME-DEPENDENT HARMONIC-OSCILLATOR BY ALGEBRAIC DYNAMICAL METHOD

Time-dependent coherent states for a time-dependent harmonic oscillato r are constructed in the framework of algebraic dynamics. These cohere nt states are gauge-covariant, and its time evolution is governed only by the solutions of a linear differential equation which describes th e motion of the corresponding classical time-dependent harmonic oscill ator. Its non-classical and quantum statistical properties can thus be controlled by a proper choice of the frequency of the harmonic oscill ator. Our coherent states reduce to Glauber coherent states in the cas e as the frequency is independent of time.