Narrow Results

A two-dimensional lattice-Boltzmann model with a hexagonal lattice is developed to simulate a boiling two-phase flow microscopically. Liquid-gas phase transition and bubble dynamics, including bubble formation, growth and deformation, are modeled by using an interparticle potential based on the van der Waals equation of state. Thermohydrodynamics is incorporated into the model by adding extra velocities to define temperature. The lattice-Boltzmann model is solved by a finite difference scheme so that numerical stability can be ensured at large discontinuity across the liquid-gas phase boundary and the narrow phase interface thickness can be attained. It is shown from numerical simulations that the model has the ability to reproduce phase transition, bubble dynamics and thermohydrodynamics while assuring numerical instability and narrow phase interface.

By using the Quantum Molecular Dynamics (QMD) model, a study on the nuclear vaporization in ${}^{40}\mathrm{\text{Ca}}+{}^{40}\mathrm{\text{Ca}}$ collision is presented for different nuclear equations of state along with a systematic comparison of different clusterization methods based on simple spatial correlations, spatial-momentum correlations, mass dependent binding energy cuts and Simulated Annealing Clusterization Algorithm (SACA). The effect of different nuclear equations of state i.e., Soft, Hard and Soft with Momentum Dependent (SMD) interactions on the energy of onset of vaporization for ${}^{40}\mathrm{\text{Ca}}+{}^{40}\mathrm{\text{Ca}}$ collisions is predicted by investigating gas/liquid content and probability of vaporization versus incident energy behavior. These two observables probe the critical point of nuclear vaporization very well. Further outcome of different clusterization algorithms on the energy of onset of nuclear vaporization is also probed and a comparison of calculations with the experimental data for ${}^{16}\mathrm{\text{O}}+{}^{80}\mathrm{\text{Br}}$ and ${}^{16}\mathrm{\text{O}}+{}^{107}\mathrm{\text{Ag}}$ collisions is carried out for different clusterization algorithms.

The existence of a liquid-gas phase transition for hot nuclear systems close to saturation densities is an interesting prediction of finite temperature nuclear many-body theory. We have applied the realistic Self-Consistent Green's Function's (SCGF) method together with the Luttinger-Ward (LW) formalism to the study of the thermodynamical (TD) properties of infinite symmetric nuclear matter. We compare our results with those obtained within the Brueckner–Hartree–Fock (BHF) theory and find substantial differences.

We address nuclear liquid-gas instablitities in the mean-field framework, using a Skyrme-like density functional. These instabilities lead to the clusterization of nuclear and compact-star matter at sub-saturation density. In this contribution, we study the extension of the spinodal region, how it affects star matter at β-equilibrium and how it is affected by the choice of different Skyrme forces. The dynamics of cluster formation is also characterized, comparing a semi-classical approach to a quantal one.

Due to the difficulty of hydrodynamic simulations to reproduce type II supernovae explosions, we investigate possible missing microscopic physics, such as neutrino trapping near the critical temperature of the nuclear liquid-gas phase transition, temperature dependant neutrino mean free paths or electron capture rates on nuclei to evaluate the impact on the improvement of the supernova outgoing shock propagation.

First-order phase transitions (PTs) with more than one globally conserved charge, so-called noncongruent PTs, have characteristic differences compared to congruent PTs (e.g., dimensionality of phase diagrams and location of critical points and endpoints). Here we discuss the noncongruent features of the QCD PT and compare it with the nuclear liquid-gas (LG) PT, for symmetric and asymmetric matter in heavy-ion collisions and neutron stars. In addition, we have identified a principle difference between the LG and the QCD PT: they have opposite slopes in the pressure-temperature plane.