The influence of quantum vacuum friction on pulsars

TL;DR

This paper revisits quantum vacuum friction (QVF) as an energy loss mechanism in pulsars, highlighting observable differences from classical models, especially in magnetic field and dipole evolution, offering potential tests for QVF.

Contribution

It provides a detailed analysis of QVF's effects on pulsar observables, proposing new ways to distinguish it from classical magnetic dipole radiation through measurable parameters.

Findings

QVF predicts contrasting evolution of magnetic dipole angle and field compared to classical models.

Different timescales associated with magnetic field and angle evolution can falsify QVF.

QVF can produce unique signatures in pulsar braking indices and magnetic evolution.

Abstract

We firstly revisit the energy loss mechanism known as quantum vacuum friction (QVF), clarifying some of its subtleties. Then we investigate the observables that could easily differentiate QVF from the classical magnetic dipole radiation for pulsars with braking indices (n) measured accurately. We show this is specially the case for the time evolution of a pulsar's magnetic dipole direction ($\dot{\phi}$) and surface magnetic field ($\dot{B}_0$). As it is well known in the context of the classic magnetic dipole radiation, $n<3$ would only be possible for positive $(\dot{B}_0/B_0 + \dot{\phi}/\tan\phi)$, which, for instance, leads to $\dot{B}_0>0$ ($\dot{\phi}>0$) when $\phi$ ($B_0$) is constant. On the other hand, we show that QVF can result in very contrasting predictions with respect to the above ones. Finally, even in the case $\dot{B}_0$ in both aforesaid models for a pulsar has the same sign, for a given $\phi$, we show that they give rise to different associated timescales, which could be another way to falsify QVF.