Constraining Hamiltonians from chiral effective field theory with neutron-star data

Abstract

Multi-messenger observations of neutron stars (NSs) and their mergers have placed strong constraints on the dense-matter equation of state (EOS). The EOS, in turn, depends on microscopic nuclear interactions that are described by nuclear Hamiltonians. These Hamiltonians are commonly derived within chiral effective field theory (EFT). Ideally, multi-messenger observations of NSs could be used to directly inform our understanding of EFT interactions, but such a direct inference necessitates millions of model evaluations. This is computationally prohibitive because each evaluation requires us to calculate the EOS from a Hamiltonian by solving the quantum many-body problem with methods such as auxiliary-field diffusion Monte Carlo (AFDMC), which provides very accurate and precise solutions but at a significant computational cost. Additionally, we need to solve the stellar structure equations for each EOS which further slows down each model evaluation by a few seconds. In this work, we combine emulators for AFDMC calculations of neutron matter, built using parametric matrix models, and for the stellar structure equations, built using multilayer perceptron neural networks, with the \texttt{PyCBC} data-analysis framework to enable a direct inference of coupling constants in an EFT Hamiltonian using multi-messenger observations of NSs. We find that astrophysical data can provide informative constraints on two-nucleon couplings despite the high densities probed in NS interiors.

8 pages, 4 figures, contains supplemental material

References in corpus (34)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• A Massive Pulsar in a Compact Relativistic Binary
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• Chiral effective field theory and nuclear forces
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• Improved nuclear matter calculations from chiral low-momentum interactions
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Dark Energy Camera Discovery of the Optical Counterpart
• Accurate nuclear radii and binding energies from a chiral interaction
• Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory
• Structure of A=10-13 nuclei with two- plus three-nucleon interactions from chiral effective field theory
• A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437$\unicode{x2013}$4715
• Ab initio predictions link the neutron skin of ${}^{208}$Pb to nuclear forces
• Three-Nucleon Low-Energy Constants from the Consistency of Interactions and Currents in Chiral Effective Field Theory
• Local chiral effective field theory interactions and quantum Monte Carlo applications
• Minimally non-local nucleon-nucleon potentials with chiral two-pion exchange including $\Delta$'s
• An updated mass-radius analysis of the 2017-2018 NICER data set of PSR J0030+0451
• The Radius of the High-mass Pulsar PSR J0740+6620 with 3.6 yr of NICER Data
• Converged ab initio calculations of heavy nuclei
• Constraining the dense matter equation of state with new NICER mass-radius measurements and new chiral effective field theory inputs
• Nuclear equation of state for arbitrary proton fraction and temperature based on chiral effective field theory and a Gaussian process emulator
• Investigating Signatures of Phase Transitions in Neutron-Star Cores
• Model reduction methods for nuclear emulators
• Eigenvector Continuation and Projection-Based Emulators
• Benchmark calculations of infinite neutron matter with realistic two- and three-nucleon potentials
• Impact of two-body currents on magnetic dipole moments of nuclei
• Probing new bosons and nuclear structure with ytterbium isotope shifts
• Neutron stars and the dense matter equation of state: from microscopic theory to macroscopic observations
• Normal ordering of three-nucleon interactions for ab initio calculations of heavy nuclei
• Maximally local two-nucleon interactions at N${}^3$LO in $\Delta$-less chiral effective field theory
• Diagrammatic ab initio methods for infinite nuclear matter with modern chiral interactions
• Neutron matter from local chiral effective field theory interactions at large cutoffs
• Emulators for Scarce and Noisy Data: Application to Auxiliary-Field Diffusion Monte Carlo for Neutron Matter
• The Radius of PSR J0437-4715 from NICER Data
• Inferring three-nucleon couplings from multi-messenger neutron-star observations