Fulfillment of expectations of precise measurements of the Casimir force

Abstract

We compare theoretical expectations for the Casimir force with the results of precise measurements. The force is calculated at finite temperature for multilayered covering of the bodies using the Lifshitz theory. We argue that the dielectric function of the metallization has to be directly measured to reach the necessary precision in the force calculation. Without knowledge of this function one can establish a well defined upper limit on the force using parameters of perfect single-crystal materials. The force measured in the torsion pendulum experiment does not contradict to the upper limit. Importance of a thin Au/Pd layer in the atomic force microscope experiments is stressed. The force measured with the microscope is larger than the upper limit at small separations between bodies. The discrepancy is significant and reproduced for both performed measurements. The origin of the discrepancy is discussed. The simplest modification of the experiment is proposed allowing to make its results more reliable and answer the question if the discrepancy has any relation with the existence of a new force.