INFLUENCE OF UNIFORMLY ACCELERATED OSCILLATOR ON QUANTUM-FIELD

The influence on a quantum scalar field in its Minkowski vacuum state induced by weak coupling of the field to a uniformly accelerated harmo nic oscillator is studied. From the perspective of a Rindler observer, the reaction of the oscillator on the quantum field distorts the Plan ckian particle spectrum of the Minkowski vacuum state and induces a ch ange of state for the quantum field even without simultaneous excitati on of the oscillator. From the perspective of an inertial observer, ap art from inducing the excitation of a Minkowski vacuum state without e xcitation of the oscillator, the reaction of the oscillator on the fie ld also gives rise to the presence of particles in the Minkowski vacuu m state. In the long time limit, when the oscillator comes into therma l equilibrium again with the Minkowski vacuum state according to a Rin dler observer, a closed expression for the particle number is worked o ut and its physical implications are discussed. EPR correlation of the Minkowski vacuum state for a Rindler observer is also disturbed by th e presence of an accelerated oscillator even in the long time limit. W hen the oscillator is viewed as a simple model of a measuring device, the result suggests that noise induced by measurement on a quantum fie ld might present difficulties for a Rindler observer who wants to upho ld EPR correlation across the event horizon.