Evolution of Neutron Star Magnetic Fields

Neutron stars are natural physical laboratories allowing us to study a plethora of phenomena in extreme conditions. In particular, these compact objects can have very strong magnetic fields with non-trivial origin and evolution. In many respects, its magnetic field determines the appearance of a neutron star. Thus, understanding the field properties is important for the interpretation of observational data. Complementing this, observations of diverse kinds of neutron stars enable us to probe parameters of electro-dynamical processes at scales unavailable in terrestrial laboratories. In this review, we first briefly describe theoretical models of the formation and evolution of the magnetic field of neutron stars, paying special attention to field decay processes. Then, we present important observational results related to the field properties of different types of compact objects: magnetars, cooling neutron stars, radio pulsars, and sources in binary systems. After that, we discuss which observations can shed light on the obscure characteristics of neutron star magnetic fields and their behaviour. We end the review with a subjective list of open problems.

Automated summary

Neutron stars serve as natural physical laboratories for studying a variety of phenomena in extreme conditions, with their magnetic fields playing a crucial role in determining their appearance. Understanding the properties of these magnetic fields is essential for interpreting observational data, while observations of different types of neutron stars provide insights into parameters of electro-dynamic processes. However, the obscure characteristics of neutron star magnetic fields still pose many open questions for research.