Braking indices and spin evolution: something is loose inside neutron stars

TL;DR

This paper discusses the challenges in measuring pulsar braking indices and explores how loosely coupled superfluid components inside neutron stars influence their spin-down behavior and evolution.

Contribution

It highlights the impact of superfluid dynamics on pulsar spin evolution and addresses measurement difficulties of braking indices in pulsars with glitches.

Findings

Superfluid inside neutron stars affects spin evolution.

Measurement of braking indices is complex and challenging.

Glitches influence the interpretation of pulsar spin-down data.

Abstract

Braking indices are used to describe the evolution of pulsars rotation, and can offer insights into the braking mechanism that dominates the slow down. Here we discuss the main difficulties associated with measuring braking indices and the complexity of interpreting these measurements. Considering recent braking index measurements on pulsars with large and regular glitches, we comment on the significant effects that the loosely coupled superfluid inside pulsars might have on their spin evolution.