Speaker
Description
We investigate the dynamical stability of neutron stars by performing radial perturbations on their stellar structure obtained after solving the hydrostatic-equilibrium equations which uses as input a collection of equations of state obtained from successive matchings between perturbative QCD at high densities and chiral effective theory at low densities and constrained by observational data at intermediate densities where a first-order transition is expected to occur. We do this by solving a pair of first-order coupled differential equations equivalent to the original Sturm-Liouville problem to obtain the fundamental-mode frequencies characterizing stable stars. We further analyze the effects of mild and large violations of the conformal bound for the speed of sound, c_{s}=1/\sqrt{3}, in stars that can possibly contain a quark matter core. We find that some neutron-star families display an unusual behavior in the mass-radius diagram which are associated to large oscillation amplitudes near the core.
