Asit karan, Ritam Mallick, Anil Kumar, Monika Sinha

We investigate the impact of dark matter on the structure and deformation of magnetars. We assume a perturbative approach for the magnetic field deformation and that the dark matter only interacts gravitationally with hardonic matter. Assuming that the DM is significantly softer than HM, we find that the magnetic field can affect dark matter through the deformation of space-time. The number of stars having a dark matter halo outside the hadronic matter surface increases with an increase in dark matter fraction and the stiffness of the dark matter equation of state. As the magnetic field deforms the stars from sphericity, we can have a situation where we have a non-symmetric dark matter halo outside the star. This can have interesting observational gravitational signatures unique to magnetars with having DM halo.