Hybrid Stars: how will we identify them?

Mark Alford (Washington University, St. Louis)

At high pressure, nuclear matter will undergo a transition to quark matter, so sufficiently heavy neutron stars may really be “hybrid stars” with quark matter cores. We discuss possible signatures of the presence of a quark matter core, such as the mass-radius relation, and the allowed range of values of the spin frequency, which is sensitive to quark matter in the core via the r-mode spindown mechanism.