Effects of isovector scalar meson on hyperon star

We study the effects of isovector-scalar ($\delta$)-meson on neutron star. Influence of $\delta$-meson on both static and rotating neutron star is discussed. Inclusion of $\delta$-meson in a neutron star system consisting of proton, neutron and electron, make the equation of state stiffer in higher density and consequently increases the maximum mass of the star. But induction of $\delta$-meson in the hyperon star decreases the maximum mass of the hyperon star. This is due to the early evolution of hyperons in presence of $\delta-$meson.