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Abstract:
The structure of neutron stars is determined by the so-called TOV equations of general relativity. Knowledge of the pressure-energy density relation is sufficient to determine the neutron star mass-radius (M-R) relation. Recent observations from X-ray telescopes, radio timing of pulsars, and gravitational wave observations, have provided several constraints on the masses and radii of neutron stars. Major efforts are being devoted to inferring the underlying pressure-energy density relation, often called the equation of state (EOS), of dense matter. This involves the inversion of the TOV relations. The close correspondence between neutron star matter pressure near the saturation density and the radii of typical
neutron stars is one example of a semi-universal relation relating the M-R relation to the EOS, as is the Yagi-Yunes I-Love relation connecting the moments of inertia and the tidal deformability of neutron stars. These relations are valid for all or nearly all equations of state to high precision. However, the inference of the EOS from mass and radius observations, which have appreciable uncertainties, is also dependent upon model dependences of the inversion method.
This talk will review the structure and observations of neutron stars and will introduce several semi-universal relations relating the mass and radius directly to the central densities and pressures of the neutron star. One important result is an analytic method of inverting an individual M-R relation to its underlying EOS to within about 0.5\%.
Bio:
James Lattimer is a Distinguished Professor of Physics & Astronomy at Stony Brook University. He received his BS from the University of Notre Dame and PhD from the University of Texas at Austin. In his 1976 PhD thesis, he proposed that the bulk of r-process elements have their origin in decompressing neutron star matter ejected from mergers involving neutron stars, a prediction apparently validated by observations of the neutron star merger GW170817 and its kilonova. He led development of a liquid-droplet model for nuclei in dense matter and produced the first open-source analytic and tabulated equations of state for hydrodynamical simulations of supernovae and neutron star mergers. His detailed models of neutrino emission from proto-neutron stars correctly predicted the essential features of the neutrino emission fortuitously observed from SN 1987A only a few months later. He established the first clear link between neutron star radii and the nuclear symmetry energy. He helped develop minimal cooling paradigm for neutron star cooling, demonstrate that the Cas A neutron star's rapid cooling is likely due to the onset of neutron superfluidity in its core, and suggest that a warm dust 'blob' in the remnant of SN 1987A is probably hiding the long-sought neutron star born in that supernovae. He is a member of NASA's Neutron Star Interior Composition ExploreR (NICER) detector team. He is a Fellow of the APS and has received Alfred P. Sloan and John Simon Guggenheim Fellowships as well as the Hans A. Bethe Prize, which is the highest APS honor in nuclear astrophysics.
Host: Prof. Sophia Han
Alternative link:
https://meeting.tencent.com/dm/dFfvvYIej7V6
#腾讯会议：546525602
会议密码：123456
Sophia Han