High-density symmetry energy and direct Urca process

2006/07/18 by Andrew W. Steiner · 80 citations
Physics and Astronomy · #Astrophysics #Gamma-ray bursts and supernovae #Geometry #Isospin #Neutron #Neutron star #Nuclear physics #Nuclear physics research studies #Physics #Process (computing) #Pulsars and Gravitational Waves Research #Quartic function #Symmetry (geometry) #astro-ph #nucl-th

paper · pdf · doi:10.1103/physrevc.74.045808

published in Physical Review C 74(4) (American Institute of Physics) · 6 pages, 3 figures, submitted to PRC

arxiv created 2006/07/18 · openalex publication_date 2006/10/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

The symmetry energy of nucleonic matter is usually assumed to be quadratic in the isospin density. While this may be justified at subsaturation densities, there is no need to enforce this restriction at supersaturation densities. The presence of a quartic term can strongly modify the critical density for the direct Urca process which leads to faster cooling of neutron stars. Neutron star cooling predictions which lie below the observational data can, for some equations of state, be repaired with a quartic term which effectively turns off the direct Urca process.

Citations

• Isospin asymmetry in nuclei and neutron stars
• The cooling of Akmal--Pandharipande--Ravenhall neutron star models

Cited by

• Hot and dense homogeneous nucleonic matter constrained by observations, experiment, and theory
• Exact versus Taylor-expanded energy density in the study of the neutron star crust–core transition
• Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII. Stiffness and stability of neutron-star matter
• THE MICROSCOPIC APPROACH TO NUCLEAR MATTER AND NEUTRON STAR MATTER