Empirical radius formulas for canonical neutron stars from bidirectionally selecting EOS features in extended Bayesian analyses of observational data

Abstract

Given the significant advancement in Bayesian inference of nuclear Equation of State (EOS) from gravitational wave and X-ray observations of neutron stars (NSs), especially since GW170817, is there a data-driven and robust empirical formula for the radius $R_{1.4}$ of canonical NSs in terms of the characteristic EOS parameters (features)? What is the single most important but currently poorly known EOS parameter for determining the $R_{1.4}$? We study these questions by extending the traditional Bayesian analysis which normally ends at presenting the marginalized posterior probability distribution functions (PDFs) of individual EOS parameters and their correlations (or sometimes only the Pearson correlation coefficients which are only reliably useful when the variables are linearly correlated while they are actually often not). Using three regression model-building methodologies: bidirectional step-wise feature selection, Least Absolute Shrinkage Selection Operator (LASSO) regression, and neural network regression on a large set of posterior EOSs and the corresponding $R_{1.4}$ values inferred from earlier comprehensive Bayesian analyses of NS observational data, we systematically and rigorously develop the most probable $R_{1.4}$ formulas with varying statistical accuracy and technical complexity. The most important EOS parameters for determining $R_{1.4}$ are found consistently in each of the feature/model selection processes to be (in order of decreasing importance): curvature $K_{sym}$, slope $L$, skewness $J_{sym}$ of nuclear symmetry energy, skewness $J_0$, incompressibility $K_0$ of symmetric nuclear matter, and the magnitude $E_{sym}({\rho }_0)$ of symmetry energy at the saturation density ${\rho }_0$ of nuclear matter.

arXiv commentPhys. Rev. C (2023) in press

References in corpus (43)

• GW170817: Measurements of Neutron Star Radii and Equation of State
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation
• Tidal Deformabilities and Radii of Neutron Stars from the Observation of GW170817
• Stringent constraints on neutron-star radii from multimessenger observations and nuclear theory
• Neutron star radii and crusts: uncertainties and unified equations of state
• Constraining Neutron-Star Matter with Microscopic and Macroscopic Collisions
• How well do we know the neutron-matter equation of state at the densities inside neutron stars? A Bayesian approach with correlated uncertainties
• Nuclear Matter and its Role in Supernovae, Neutron Stars and Compact Object Binary Mergers
• Symmetry Parameter Constraints From A Lower Bound On The Neutron-Matter Energy
• Neutron star tidal deformability and equation of state constraints
• Nuclear constraints on properties of neutron star crusts
• Constraints on the Symmetry Energy Using the Mass-Radius Relation of Neutron Stars
• Gravitational waves from neutron star mergers and their relation to the nuclear equation of state
• Progress in Constraining Nuclear Symmetry Energy Using Neutron Star Observables Since GW170817
• Towards Understanding Astrophysical Effects of Nuclear Symmetry Energy
• Dense Nuclear Matter Equation of State from Heavy-Ion Collisions
• Combined Constraints on the Equation of State of Dense Neutron-Rich Matter from Terrestrial Experiments and Observations of Neutron Stars
• A survey of the parameter space of the compressible liquid drop model as applied to the neutron star inner crust
• Extracting Nuclear Symmetry Energies at High Densities from Observations of Neutron Stars and Gravitational Waves
• Locating the inner edge of neutron star crust using terrestrial nuclear laboratory data
• Bayesian Inference of High-density Nuclear Symmetry Energy from Radii of Canonical Neutron Stars
• The nuclear symmetry energy and stability of matter in neutron star
• GW190814's secondary component with mass $(2.50-2.67)$ M${}_{\odot }$ as a super-fast pulsar
• Bayesian Inference of the Symmetry Energy of Super-Dense Neutron-Rich Matter from Future Radius Measurements of Massive Neutron Stars
• Bayesian analysis of the crust-core transition with a compressible liquid-drop model
• Neutron star equation of state: QMF modeling and applications
• Interdependence of different symmetry energy elements
• Implications of the mass $M=2.17_{-0.10}^{+0.11}$M${}_{\odot }$ of PSR~J0740+6620 on the Equation of State of Super-Dense Neutron-Rich Nuclear Matter
• Bayesian inference of dense matter EOS encapsulating a first-order hadron-quark phase transition from observables of canonical neutron stars
• Delineating Effects of Nuclear Symmetry Energy on the Radii and Tidal Polarizabilities of Neutron Stars
• Imprint of the symmetry energy on the inner crust and strangeness content of neutron stars
• Curvature-slope correlation of nuclear symmetry energy and its imprints on the crust-core transition, radius and tidal deformability of canonical neutron stars
• Constraints on the symmetry energy from observational probes of the neutron star crust
• Nucleonic metamodelling in light of multimessenger, PREX-II and CREX data
• Impact of NICER's Radius Measurement of PSR J0740+6620 on Nuclear Symmetry Energy at Suprasaturation Densities
• Universal correlations in the nuclear symmetry energy, slope parameter, and curvature
• Constraints on the muon fraction and density profile in neutron stars
• Neutron star mass formula with nuclear saturation parameters for asymmetric nuclear matter
• Impact of Symmetry Energy on Sound Speed and Spinodal Decomposition in Dense Neutron-Rich Matter
• Properties of First-Order Hadron-Quark Phase Transition from Inverting Neutron Star Observables
• Empirical neutron star mass formula based on experimental observables
• Neutron star mass formula with nuclear saturation parameters

Cited by in corpus (13)

• Bayesian Inference of Fine-Features of Nuclear Equation of State from Future Neutron Star Radius Measurements to 0.1km Accuracy
• Impact of The Newly Revised Gravitational Redshift of X-ray Burster GS 1826-24 on The Equation of State of Supradense Neutron-Rich Matter
• Novel Scalings of Neutron Star Properties from Analyzing Dimensionless Tolman--Oppenheimer--Volkoff Equations
• Impact of the nuclear equation of state on the formation of twin stars
• Inferring the Equation of State from Neutron Star Observables via Machine Learning
• Neural Network Emulation of Flow in Heavy-Ion Collisions at Intermediate Energies
• Unraveling Trace Anomaly of Supradense Matter via Neutron Star Compactness Scaling
• Bayesian inference of nuclear incompressibility from collective flow in mid-central Au+Au collisions at 400--1500 MeV/nucleon
• Novel features of asymmetric nuclear matter from terrestrial experiments and astrophysical observations of neutron stars
• Anisotropic pressure effect on central EOS of PSR J0740+6620 in the light of dimensionless TOV equation
• Precise constraint on properties of neutron stars through new universal relations and astronomical observations
• Bayesian Constraints on the Neutron Star Equation of State with a Smooth Hadron-Quark Crossover
• Bayesian Inference of fine-features of dense matter EOS from future high-precision data of neutron star radii