We study possible effects of a dark matter ( DM ) core on the maximum mass of a neutron star ( NS ) , on the mass-radius relation and on the NS tidal deformability parameter \Lambda .
We show that all these quantities would in general be reduced in the presence of a DM core .
In particular , our calculations indicate that the presence of a DM core with a mass fraction \sim 5 \% could affect significantly the interpretation of these NS data as constraints on the nuclear equation of state ( EOS ) , potentially excluding some EOS models on the basis of the measured mass of PSR J0348+0432 , while allowing other EOS models to become consistent with the LIGO/Virgo upper limit on \Lambda .
Specific scenarios for generating such DM cores are explored in an Appendix .