BPS Skyrme neutron stars in generalized gravity

Abstract

We study the coupling of nuclear matter described by the BPS Skyrme model to generalized gravity. Concretely, we consider the Starobinsky model which provides the leading-order correction to the Einstein-Hilbert action. Static solutions describing neutron stars are found both for the full field theory and for the mean-field approximation. We always consider the full Starobinsky model in the nonperturbative approach, using appropriately generalized shooting methods for the numerical neutron star calculations. Many of our results are similar to previous investigations of neutron stars for the Starobinsky model using other models of nuclear matter, but there are some surprizing discrepancies. The "Newtonian mass" relevant for the surface redshift, e.g., results larger than the ADM mass in our model, in contrast to other investigations. This difference is related to the particularly high stiffness of nuclear matter described by the BPS Skyrme model and offers an interesting possibility to distinguish different models of nuclear matter within generalized gravity.

LaTex, 28 pages, 13 figures; v2: minor changes

References in corpus (14)

• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Shapiro delay measurement of a two solar mass neutron star
• Nonperturbative models of quark stars in $f(R)$ gravity
• Constraining the Neutron Star Mass-Radius Relation and Dense Matter Equation of State with NICER. II. Emission from Hot Spots on a Rapidly Rotating Neutron Star
• Slowly rotating neutron and strange stars in $R^2$ gravity
• Skyrmions, instantons and holography
• A BPS Skyrme model and baryons at large Nc
• On the 1/c Expansion of f(R) Gravity
• Light Nuclei of Even Mass Number in the Skyrme Model
• BPS Skyrmions as neutron stars
• Scalar field mass in generalized gravity
• Generalized Skyrme model with the loosely bound potential
• The Dielectric Skyrme model
• Neutron stars within the Skyrme model