Gravitational Waves from Pulsars and Their Braking Indices: The Role of a Time Dependent Magnetic Ellipticity

TL;DR

This paper investigates how time-dependent magnetic ellipticities influence pulsar braking indices and gravitational wave amplitudes, revealing that magnetic ellipticity effects are minimal compared to traditional spindown estimates.

Contribution

It introduces a model incorporating time-dependent magnetic ellipticities to refine calculations of pulsar braking indices and gravitational wave amplitudes.

Findings

Magnetic ellipticity effects are negligible for gravitational wave amplitude estimates.

The gravitational wave amplitude from pulsars is much smaller than the spindown limit predicts.

Time dependence of magnetic ellipticity has limited impact on observable gravitational waves.

Abstract

We study the role of time dependent magnetic ellipticities ($\epsilon_{B}$) on the calculation of the braking index of pulsars. Moreover, we study the consequences of such a $\epsilon_{B}$ on the amplitude of gravitational waves (GWs) generated by pulsars with measured braking indices. We show that, since the ellipticity generated by the magnetic dipole is extremely small, the corresponding amplitude of GWs is much smaller than the amplitude obtained via the spindown limit.