Thermodynamic instabilities in compact stars

We investigate the presence of thermodynamic instabilities in the high density nuclear matter reached in the central core of compact stars. In the framework of a relativistic mean-field theory, we study the cold hadronic equation of state in beta-equilibrium and charge neutral matter, including hyperons and Δ-isobar degrees of freedom. By considering fluctuations of the electric charge concentration of strongly interacting matter, we analyze a finite density phase transition characterized by pure hadronic matter with both mechanical instability that by chemical-diffusive instability. It turns out that in this situation hadronic phases with different values of electric charge content may coexist, with several implications in the bulk properties of compact stars.