Physical Society Colloquium

Inside Neutron Stars: Theoretical Speculations & Observational Constraints

Sanjay Reddy

T-16 Nuclear Physics Group
Los Alamos National Laboratory

The interior of a neutron star contains matter at extreme density - well in excess of the density inside an atomic nucleus. Although such cold and dense matter cannot be directly probed by terrestrial experiments, theories of very dense matter are constrained by empirical properties of nuclei. In my talk I will describe various theories of dense matter and possible phase transitions. Finally, I will argue that observations of neutron star phenomena and the theory needed to interpret these observations have already given us new insights and promise to provide powerful new constraints for dense matter theory in the near future.