The Role of Hyperons in Neutron Stars

Studies of the equation of state of dense matter in beta-equilibrium suggest that hyperons must play a role. On the other hand, the appearance of hyperons has the effect of lowering the rate of increase in pressure as the density rises. This creates challenges for hadronic models to produce neutron stars with the largest masses observed. We will review recent work on the inclusion of hyperons in the theoretical calculations of neutron star properties, including the possibility of new short-distance forces and a potential transition to quark matter.