Plasma Magnetosphere of Rotating Magnetized Neutron Star in the Braneworld

TL;DR

This paper investigates how braneworld modifications influence the plasma magnetosphere of rotating neutron stars, revealing effects on electric fields, charge density, and particle acceleration, with implications for energy loss and magnetospheric dynamics.

Contribution

It provides an analytical framework for understanding the impact of brane tension on neutron star magnetospheres, including modifications to electric fields and particle motion.

Findings

Brane tension modifies the electrostatic potential and charge density along open magnetic field lines.

Negative brane charge amplifies plasma modes initiated by Goldreich-Julian charge density.

Brane tension significantly alters particle acceleration conditions in the polar cap region.

Abstract

Plasma magnetosphere surrounding rotating magnetized neutron star in the braneworld has been studied. For the simplicity of calculations Goldreich-Julian charge density is analyzed for the aligned neutron star with zero inclination between magnetic field and rotation axis. From the system of Maxwell equations in spacetime of slowly rotating star in braneworld, second-order differential equation for electrostatic potential is derived. Analytical solution of this equation indicates the general relativistic modification of an accelerating electric field and charge density along the open field lines by brane tension. The implication of this effect to the magnetospheric energy loss problem is underlined. It was found that for initially zero potential and field on the surface of a neutron star, the amplitude of the plasma mode created by Goldreich-Julian charge density will increase in the presence of the negative brane charge. Finally we derive the equations of motion of test particles in magnetosphere of slowly rotating star in the braneworld. Then we analyze particle motion in the polar cap and show that brane tension can significantly change conditions for particle acceleration in the polar cap region of the neutron star.