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A dynamical description of neutron star crusts. V. de la Mota , F. Sébille and Ph. Eudes. Crust: Exotic Shapes. at sub-nuclear densities: frustration. ρ ≤ 10 14 g/cm 3 T≈ 0.1 MeV. « Nuclear Pasta ». crust. spheres rods slabs cylindrical holes spherical holes. fluid.
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A dynamical description of neutron star crusts V. de la Mota, F. Sébille and Ph. Eudes
Crust: Exotic Shapes at sub-nuclear densities: frustration ρ ≤ 1014 g/cm3 T≈ 0.1MeV « Nuclear Pasta » crust • spheres • rods • slabs • cylindrical holes • spherical holes fluid spheres rods slabs complex phases uniform ρ 0 ρ∞
Pasta formation astrophysical consequences: * neutrino scattering * elastic properties of the crust connection with nuclear collisions * fragment formation * EoS sensitivity
A dynamical model The DYnamicalWAvelets in Nuclei Model Advantage: simulation of the dynamical processes in inhomogeneous nuclear matter using a large number of nucleons without any assumptions on the structure of nuclear matter. It is in contrast to the many previous studies employing static frameworks.
The Model Studying the behavior of matter at the crust: interacting nucleons in a uniform electron background : moving basis (Gabor wavelets)
★ ½ neutrons q= - ½ protons =0.145fm-3 J=31.5 MeV c=20 MeV lattice calculation with Ewald summation technique ★ K. Oyamatsu and K. Iida, Phys. Rev. C 75 (2007) 015801
neutron matter FPB. Friedman et B.R. Pandharipande, Nucl. Phys. 361(1981) 501 SKM H. Krivine et al, Nucl. Phys. A 336 (1980) 155 Sly4 F. Douchin et al, Phys. Lett. B 435 (2000) 107 static properties of neutron matter
The initial condition L SC cells 16O T=0
The dynamical evolution SCC lattice oxygen xp=0.1 <ρ>=0.0726fm- 3 L=23.1fm ρt=0.065fm-3 structures m.i.a. techniques ρt=0.05fm- 3 ρt=0.1fm- 3 t=210 fm/c shapes ρt embedded structures ☐ G. Watanabe et al. Phys. Rev. C 69 (2004) 055805
Lattice perturbations xp=0.5 SCC O cell <ρ>=0.06 fm-3 ρt=0.04 fm-3 xp=0.2 FCC O cell xp=0.2 <ρ>=0.03 fm-3 the tracks of the initial configuration are washed out the effects depend on the proton fraction value and on the symmetry of the lattice
Influence of the EoS non perturbed O SCC lattice xp=0.2 stiffer force favours spherical & sponge-like structures, restrains cylinder & slabs.
Summary Non dissipative dynamical description: a small initial deposited energy permits to explore the landscape of structures not only the ordered five standard types of pasta emerge naturally but also intermediate shapes between them, conservation of lattice symmetries, correlated systems: ordered phases, perturbations effects destroy initial symmetries in the case of the light O systems, sensitivity to the asymmetry dependent term of the potential.
Outlooks Heterogeneous systems: lattices with different chemical species Effective force: non-local forces, spin-orbit terms EoS sensitivity Finite temperatures Dissipative effects and density fluctuations Transport properties