# On the change of old neutron star masses with galactocentric distance

## TL;DR

This paper investigates how pulsar masses vary with galactocentric distance due to dark matter effects, suggesting that dark matter interactions influence neutron star masses and can inform galactic dark matter properties.

## Contribution

It introduces a model linking pulsar mass decrease to dark matter density and self-interaction, proposing observational tests to constrain dark matter characteristics.

## Key findings

- Pulsar mass decreases towards the galactic center.
- Dark matter density profile affects mass reduction rate.
- Self-interaction strength influences the extent of mass change.

## Abstract

We show that the pulsar mass depends on the environment, and that it decreases going towards the center of the Milky Way. This is due to two combined effects, the capture and accumulation of self-interacting, non-annihilating dark matter by pulsars, and the increase of the dark matter density going towards the galactic center. We show that mass decrease depends both on the density profile of dark matter, steeper profiles producing a faster and larger decrease of the pulsar mass, and on the strength of self-interaction. Once future observations will provide the pulsar mass in a dark matter rich environment, close to the galactic center, the present result will be able to put constraints on the characteristics of our Galaxy halo dark matter profile, on the nature of dark matter, namely on its annihilating or non-annihilating nature, on its strength of self-interaction, and on the particle mass.