NuSym23, XIth International Symposium on Nuclear Symmetry Energy

Microscopic nuclear theory is based on the tenet that atomic nuclei and nucleonic matter can be accurately described as collections of point-like nucleons interacting via two- and many-body forces obeying nonrelativistic quantum mechanics---and the concept of the ab initio approach is to calculate nuclear systems accordingly. The forces are fixed in free-space scattering and must be accurate....

Modern formulations of nuclear forces, such as pionless or chiral effective field theory, are typically based on a perturbative approach. Such interactions are then often employed by state-of-the-art nuclear many-body techniques (such as quantum Monte Carlo) which are non-perturbative in nature. The equation of state of a compact star is thus the result of this interplay of perturbative...

Recently, quite significant progress has been made in the description of nuclear matter and, in particular, its symmetry energy, at sufficiently high densities using skyrmion crystals and their semiclassical quantization. We briefly review these recent results and describe the challenges which still must be mastered in order to establish the Skyrme model framework as a reliable tool for the...

Infinite nuclear matter is a suitable laboratory to learn about nuclear forces in many-body systems. Modern theoretical predictions of neutron-rich matter are particularly timely in view of recent and planned measurements of observables which are sensitive to the equation of state of isospin-asymmetric matter. For these reasons, over the past several years we have taken a broad look at the...

The last decade observational data show that massive neutron star have masses
above 2.1 Msun what indicate rather stiff EOS, whereas the lightweight
star observed by NICER and HESS appears to be very compact what suggest rather
soft EOS. Such opposite properties (stiff at higher densities and soft at lower)
are available in RMF nuclear model equipped with new kind of crossing...

Large-scale models of nuclear structure play an essential role in many astrophysics applications. Nucleosynthesis simulations of heavy elements, through the rapid neutron-capture process (or r-process), for example, require nuclear information inputs across the whole nuclear chart, far beyond the region where experimental data is available. Likewise, describing the extremely dense neutron-rich...

We study the pionic self-energy and its impact on the energy-momentum dispersion relation of
pion in neutron-rich conditions such as interior of a neutron star. In such neutron-rich state, the
negatively charged pions can be produced copiously. Furthermore, these negatively charged pions
can form a Bose-Einstein condensate with zero momentum above nuclear saturation densities. In
this...

It is still a challenging task to derive the symmetry energy and equation of state for neutron stars from the underlying realistic nucleon-nucleon interaction. The relativistic Brueckner-Hartree-Fock (RBHF) theory provides a relativistic ab-initio approach, which is able to reproduce saturation properties of symmetric nuclear matter without three-body forces. However, most of the past work...

We present results for the equation of state of asymmetric nuclear matter at finite temperature based on
chiral effective field theory interactions to next-to-next-to-next-to-leading order. Our results assess
the theoretical uncertainties from the many-body calculation and the chiral expansion. Using a
Gaussian process emulator for the free energy, we derive the thermodynamic properties of...