A summation formula over the zeros of a combination of the associated Legendre functions with a physical application

Abstract

By using the generalized Abel-Plana formula, we derive a summation formula for the series over the zeros of a combination of the associated Legendre functions with respect to the degree. The summation formula for the series over the zeros of the combination of the Bessel functions, previously discussed in the literature, is obtained as a limiting case. As an application we evaluate the Wightman function for a scalar field with general curvature coupling parameter in the region between concentric spherical shells on background of constant negative curvature space. For the Dirichlet boundary conditions the corresponding mode-sum contains series over the zeros of the combination of the associated Legendre functions. The application of the summation formula allows us to present the Wightman function in the form of the sum of two integrals. The first one corresponds to the Wightman function for the geometry of a single spherical shell and the second one is induced by the presence of the second shell. The boundary-induced part in the vacuum expectation value of the field squared is investigated. For points away from the boundaries the corresponding renormalization procedure is reduced to that for the boundary-free part.

14 pages

References in corpus (5)

• Casimir effect in rugby-ball type flux compactifications
• Spinor Casimir effect for concentric spherical shells in the global monopole spacetime
• Scalar Casimir densities for cylindrically symmetric Robin boundaries
• Wightman function and scalar Casimir densities for a wedge with two cylindrical boundaries
• Summation formula over the zeros of the associated Legendre function with a physical application

Cited by in corpus (3)

• Wightman function and the Casimir effect for a Robin sphere in a constant curvature space
• The Casimir densities for a sphere in the Milne universe
• Origin of quantum shape effect