The Casimir Effect in Relativistic Quantum Field Theories

We review recent developments in the Casimir effect which arises in quantization volumes restricted by material boundaries and in spaces with non-Euclidean topology. The starting point of our discussion is the novel exact solution for the electromagnetic Casimir force in the configuration of a cylinder above a plate. The related work for the scalar Casimir effect in sphere-plate configuration is also considered, and the application region of the proximity force theorem is discussed. Next we consider new experiments on the measurement of the Casimir force between metals and between metal and semiconductor. The complicated problem connected with the theory of the thermal Casimir force between real metals is analyzed in detail. The present situation regarding different theoretical approaches to the resolution of this problem is summarized. We conclude with new constraints on non-Newtonian gravity obtained using the results of latest Casimir force measurements and compare them with constraints following from the most recent gravitational experiments.