Energy density in the Casimir effect
Abstract
We compute the expectations of the squares of the electric and magnetic fields in the vacuum region outside a halfspace filled with a uniform dispersive dielectric. We find a positive energy density of the electromagnetic field which diverges at the interface despite the inclusion of dispersion in the calculation. We also investigate the mean squared fields and the energy density in the vacuum region between two parallel halfspaces. Of particular interest is the sign of the energy density. We find that the energy density is described by two terms: a negative position independent (Casimir) term, and a positive position dependent term with a minimum value at the center of the vacuum region. We argue that in some cases, including physically realizable ones, the negative term can dominate in a given region between the two halfspaces, so the overall energy density can be negative in this region.
 Publication:

Physical Review D
 Pub Date:
 August 2002
 DOI:
 10.1103/PhysRevD.66.045026
 arXiv:
 arXiv:quantph/0204125
 Bibcode:
 2002PhRvD..66d5026S
 Keywords:

 12.20.Ds;
 03.70.+k;
 04.62.+v;
 77.22.Ch;
 Specific calculations;
 Theory of quantized fields;
 Quantum field theory in curved spacetime;
 Permittivity;
 Quantum Physics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 16 pages, 4 figures