13 research outputs found
Dispersion Forces Between Fields Confined to Half Spaces
We consider the Casimir effect for a scalar field interacting with another
scalar field that is confined to two half spaces. This model is aimed to mimic
the interaction of the photon field with matter in two slabs. We use Dirichlet
boundary conditions on the interfaces for the fields in the half spaces and
calculate their one-loop contribution to the wave equation for the other field.
We perform the ultraviolet renormalization and develop a convenient formalism
for the calculation of the vacuum energy in this configuration.Comment: 9 pages, 2 figure
Vacuum Interaction of Crossed Cosmic Strings
In this paper, we consider the vacuum energy of a scalar field in the spacetime of two non-parallel cosmic strings. To this end, we obtain metrics for orthogonal straight cosmic strings and for slightly nonparallel strings. In the first case, we derive the separation-dependent part of the vacuum energy in the leading order of string tension. The dependence of the vacuum energy on separation differs from that known for parallel strings. For two strings inclined at a small angle to each other, the approximation used simply reproduces the result for parallel strings, since the angle dependence enters the next to leading order. The results are compared with the Casimir interaction between two inclined cylinders
Mass and Magnetic Moment of the Electron and the Stability of QED—A Critical Review
The anomalous magnetic moment of the electron, first calculated by Schwinger, lowers the ground state energy of the electron in a weak magnetic field. It is a function of the field and changes signs for large fields, ensuring the stability of the ground state. This has been shown in the past 50 years in numerous papers. The corresponding corrections to the mass of the electron have also been investigated in strong fields using semiclassical methods. We critically review these developments and point out that the calculation for low-lying excited states raises questions. Also, we calculate the contribution from the tadpole diagram, the relevance of which was observed only quite recently