Shedding Light on the EOS-Gravity Degeneracy and Constraining the Nuclear Symmetry Energy from the Gravitational Binding Energy of Neutron Stars

Abstract

A thorough understanding of properties of neutron stars requires both a reliable knowledge of the equation of state (EOS) of super-dense nuclear matter and the strong-field gravity theories simultaneously. To provide information that may help break this EOS-gravity degeneracy, we investigate effects of nuclear symmetry energy on the gravitational binding energy of neutron stars within GR and the scalar-tensor subset of alternative gravity models. We focus on effects of the slope $L$ of nuclear symmetry energy at saturation density and the high-density behavior of nuclear symmetry energy. We find that the variation of either the density slope $L$ or the high-density behavior of nuclear symmetry energy leads to large changes in the binding energy of neutron stars. The difference in predictions using the GR and the scalar-tensor theory appears only for massive neutron stars, and even then is significantly smaller than the difference resulting from variations in the symmetry energy.

To appear in the Proceedings of the 13th international symposium on Origin of Matter and Evolution of Galaxies (OMEG2015) , June 24-27, 2015, Beijing, China

References in corpus (11)

• Neutron Star Observations: Prognosis for Equation of State Constraints
• Tests of general relativity from timing the double pulsar
• The relativistic pulsar-white dwarf binary PSR J1738+0333 II. The most stringent test of scalar-tensor gravity
• Relativistic effective interaction for nuclei, giant resonances, and neutron stars
• Non-perturbative and self-consistent models of neutron stars in R-squared gravity
• Constraining the High-Density Behavior of Nuclear Symmetry Energy with the Tidal Polarizability of Neutron Stars
• Generic Constraints on the Relativistic Mean-Field and Skyrme-Hartree-Fock Models from the Pure Neutron Matter Equation of State
• What does a measurement of mass and/or radius of a neutron star constrain: Equation of state or gravity?
• Impact of the equation-of-state -- gravity degeneracy on constraining the nuclear symmetry energy from astrophysical observables
• Observational discrimination of Eddington-inspired Born-Infeld gravity from general relativity
• Breaking the EOS-Gravity Degeneracy with Masses and Pulsating Frequencies of Neutron Stars