R-mode Instability of Neutron Star with Non-Newtonian Gravity

The Chandrasekhar-Friedmann-Schutz(CFS) instabilities of r-modes for canonical neutron stars(1.4 M ⊙) with rigid crusts are investigated by using an equation of state of asymmetric nuclear matter with super-soft symmetry energy,where the non-Newtonian gravity proposed in the grand unification theories is also considered.Constrained by the observations of the masses and the spin frequencies for neutron stars,the boundary of the r-mode instability window for a canonical neutron star is obtained,and the results show that the observed neutron stars are all outside the instability window,which is consistent with the theoretical expectation.In addition,an upper limit of the non-Newtonian gravity parameters is also given.