We calculate the exact Casimir interaction energy between two perfectly conducting, very long, eccentric cylindrical shells using a mode summation technique. Several limiting cases of the exact formula for the Casimir energy corresponding to this configuration are studied both analytically and numerically. These include concentric cylinders, cylinder-plane, and eccentric cylinders, for small and large separations between the surfaces. For small separations we recover the proximity approximation, while for large separations we find a weak logarithmic decay of the Casimir interaction energy, typical of cylindrical geometries.
Casimir interaction between a sphere and a cylinder
本文研究了Dirichlet边界条件、Neumann边界条件和理想导电边界条件下球与柱之间的Casimir相互作用。推广的运营商的方法开发的惠特曼[IEEE trans. 36,1078(1988)],我们计算了球和柱之间的标量和矢量平移矩阵,从而明确地写出了Casimir相互作用能的精确TGTG公式。在标量情形下,该公式清楚地表明Casimir相互作用力在所有分离处都是吸引力。Casimir相互作用能的大分离首项直接由精确公式计算。对于Dirichlet边界条件、Neumann边界条件和理想导电边界条件,其阶分别为$\sim \hbar c R_1/[L^2\ln(L/R_2)]$、$\sim \hbar c R_1^3R_2^2/L^6$和$\sim \hbar c R_1^3/[L^4\ln(L/R_2)]$,其中$R_1$和$R_2$分别为球和柱的半径,$L$为球和柱的中心距.
We study the relationship between the quantization of a massless scalar field on the two-dimensional Einstein cylinder and in a spacetime with a time machine. We find that the latter picks out a unique prescription for the state of the zero mode in the Einstein cylinder. We show how this choice arises from the computation of the vacuum Wightman function and the vacuum renormalized stress-energy tensor in the time-machine geometry. Finally, we relate the previously proposed regularization of the zero mode state as a squeezed state with the time-machine warp parameter, thus demonstrating that th…
The exact solutions of the complete (1+3)-dimensional Dirac equation of fermions moving in ideal Aharonov-Bohm (AB) rings and cylinders are used for deriving the exact expressions of the relativistic partial currents. It is shown that these currents can be related to the derivative of the fermion energy with respect to the flux parameter, just as in the non-relativistic case. However, a new and remarkable relativistic effect is the saturation of the partial currents for high values of the total angular momentum. Based on this property, the total relativistic persistent currents at $T=0$ is eva…