[Prex] An overview of existing and new nuclear and astrophysical constraints on the equation of state of neutron-rich dense matter

[Jay Benesch]

just in case

https://arxiv.org/abs/2402.04172

An overview of existing and new nuclear and astrophysical constraints on 
the equation of state of neutron-rich dense matter

Hauke Koehn, Henrik Rose, Peter T. H. Pang, Rahul Somasundaram, Brendan 
T. Reed, Ingo Tews, Adrian Abac, Oleg Komoltsev, Nina Kunert, Aleksi 
Kurkela, Michael W. Coughlin, Brian F. Healy, Tim Dietrich

Through continuous progress in nuclear theory and experiment and an 
increasing number of neutron-star observations, a multitude of 
information about the equation of state (EOS) for matter at extreme 
densities is available. Here, we apply these different pieces of data 
individually to a broad set of physics-agnostic candidate EOSs and 
analyze the resulting constraints. Specifically, we make use of 
information from chiral effective field theory, perturbative quantum 
chromodynamics, as well as data from heavy-ion collisions and the 
PREX-II and CREX experiments. We also investigate the impact of current 
mass and radius measurements of neutron stars, such as radio timing 
measurements of heavy pulsars, NICER data, and other X-ray observations. 
We augment these by reanalyses of the gravitational-wave (GW) signal 
GW170817, its associated kilonova AT2017gfo and gamma-ray burst 
afterglow, the GW signal GW190425, and the GRB211211A afterglow, where 
we use improved models for the tidal waveform and kilonova light curves. 
Additionally, we consider the postmerger fate of GW170817 and its 
consequences for the EOS. This large and diverse set of constraints is 
eventually combined in numerous ways to explore limits on quantities 
such as the typical neutron-star radius, the maximum neutron-star mass, 
the nuclear symmetry-energy parameters, and the speed of sound. Based on 
the priors from our EOS candidate set, we find the radius of the 
canonical 1.4 M⊙ neutron star to be R1.4=12.27+0.83−0.94 km and the TOV 
mass MTOV=2.26+0.45−0.22 M⊙ at 95% credibility, when including those 
constraints where systematic uncertainties are deemed small. A less 
conservative approach, combining all the presented constraints, 
similarly yields R1.4=12.20+0.53−0.50 km and MTOV=2.31+0.08−0.20 M⊙.

Comments:	49 pages, 32 figures, webinterface for custom constraint 
combinations in this https URL 
https://enlil.gw.physik.uni-potsdam.de/eos_constraints
Subjects:	High Energy Astrophysical Phenomena (astro-ph.HE); General 
Relativity and Quantum Cosmology (gr-qc); Nuclear Experiment (nucl-ex); 
Nuclear Theory (nucl-th)
Report number:	LA-UR-24-20420
Cite as:	arXiv:2402.04172 [astro-ph.HE]