Vacuum bosonic currents induced by a compactified cosmic string in dS background

TL;DR

This paper studies vacuum bosonic currents around a compactified cosmic string in de Sitter space, revealing how magnetic fluxes and compactification influence quantum current densities, with detailed calculations and comparisons to fermionic cases.

Contribution

It provides a detailed analysis of bosonic vacuum currents in a cosmic string background with compactification, including explicit formulas and decomposition of effects, extending previous fermionic studies.

Findings

Current densities are decomposed into uncompactified and compactification-induced parts.

Quantum numbers become discrete due to compactification, affecting current calculations.

Results show the influence of magnetic fluxes and geometry on vacuum currents.

Abstract

In this paper, we investigate the vacuum bosonic currents in the geometry of a compactified cosmic string in the background of the de Sitter spacetime. The currents are induced by magnetic fluxes, one running along the cosmic string and another one enclosed by the compact dimension. In order to develop this analysis, we obtain the complete set of normalized bosonic wave-functions obeying a quasiperiodicity condition. In this context, we calculate the azimuthal and axial current densities. Due to the quasiperiodicity condition, the quantum number associated with the compactification of the string along its axis becomes discrete, and we use the Abel-Plana summation formula to evaluate the non-vanishing current densities. We show that these quantities are explicitly decomposed into two contributions: one corresponds to the geometry of a straight uncompactified cosmic string and the other is induced by the compactification. We also compare the results with the literature in the case of a massive fermionic field in the same geometry.