INT 25-94W Highlights Report
Nuclear Physics in Mergers -- Going Beyond the Equation of State
September 8-12, 2025
A. Haber, E. Most, C. Raithel
Snapshot of a binary neutron star merger simulation.
Image courtesy of Elias R. Most, California Institute of Technology, USA.
Considerable efforts to investigate the equation of state of dense matter by observing gravitational waves from neutron star mergers, mainly by constraining the neutron star radius, have been made in recent years. However, a wide array of phenomena cannot be studied just by investigating the static properties of nuclear matter. With next-generation gravitational wave detectors anticipated for the next decade, there will soon be exciting, new opportunities to probe effects beyond the EOS in nuclear matter.
To learn as much as possible from the forthcoming observations, significant improvements in our understanding and capabilities of how dense matter behaves in extreme environments are necessary. Beyond the equation-of-state physics like flavor equilibration, neutrino physics, exotic degrees of freedom, (color-) superfluidity and superconductivity, and beyond-the-standard-model particles might leave direct measurable imprints on observed signals.
Our workshop brought together experts from different areas of nuclear and particle physics, astrophysics, and gravitational theory to discuss the necessary steps and advances required for us to fully leverage the opportunities posed by multi-messenger gravitational astronomy in the coming years and beyond.