Pulsar magnetospheres in General Relativity

TL;DR

This paper models pulsar magnetospheres within full General Relativity, quantifying relativistic effects on luminosity and braking index, and providing analytical expressions based on numerical simulations.

Contribution

It introduces a comprehensive GR-based model of pulsar magnetospheres, including relativistic corrections and analytical luminosity expressions.

Findings

Relativistic effects increase pulsar luminosity slightly.

Corrections depend on star's angular velocity, compactness, and misalignment.

Braking index shows a slight increase due to relativistic effects.

Abstract

The main contribution to the pulsar power can be calculated by assuming a rotating magnetically-dominated magnetosphere described by the force-free approximation. Although this simple model has been used thoroughly to study pulsar magnetospheres in the flat spacetime regime, only few works have considered the relativistic corrections introduced by the curvature and frame-dragging effects induced by a rotating neutron star. Here we revisit the problem and describe pulsar magnetospheres within full General Relativity, quantifying the corrections as a function of the angular velocity, the compactness of the star and the misalignment angle between the spin and the magnetic dipole. We provide analytical expressions for the pulsar luminosity by fitting our numerical results. Finally, we also analyze the effect of the relativistic corrections on the braking index, which indicates a slight increment in its value.