# Bounds on Neutron- Mirror Neutron Mixing from Pulsar Timings and Gravitational Wave Detections

## TL;DR

This paper investigates how neutron-mirror neutron mixing affects neutron star properties and uses pulsar timing and gravitational wave data to constrain the possible mixing parameters, providing new limits on this hypothetical phenomenon.

## Contribution

It introduces new astrophysical constraints on neutron-mirror neutron mixing based on pulsar timing and gravitational wave observations, refining previous bounds.

## Key findings

- Constraints exclude large regions of mixing parameter space
- Pulsar timing limits neutron-mirror neutron transition rates
- Gravitational wave data further restrict mixing scenarios

## Abstract

The mass loss in putative neutron star to mixed neutron - mirror neutron star transition implies a significant change of orbital period. The precise constancy of the latter can restrict scenarios recently suggested where neutron to mirror neutron mixing occurring in neutron stars, transforms them into mixed stars helping explain the narrow mass distribution observed for pulsars in binary systems. The observation of a very old millisecond pulsar with a mass of 2 solar masses is an additional strong constraint on the above transition.We also note that the observed gravitational waves signals from neutron-neutron stars merger constrain the neutron to mirror neutron transitions inside neutron stars. These considerations exclude a large region in the $\epsilon'$, $\delta m'$ plane of the neutron-mirror neutron mixing and mass