Quantum nondemolition measurements of a particle in an inhomogeneous gravitational field (Q5947435)

This is a clearly written and interesting paper. The definition of quantum demolition measurements are those where disturbances of complementary variables do not affect the evolution of the chosen variable. The measurement process of the position of a particle moving in an inhomogeneous field is considered. This problem is relevant in the theory of measurement of positions of elements of a gravitational wave attena. The theory is clearly developed and this is followed by an extensive discussion and comparisons with the measurement process for quantum demolition examples.