Collective excitations in the neutron stars' crust

Titolo: Collective excitations in the neutron stars' crust

Relatore: Dr. Urban, Michael

Abstract: Neutron stars contain an inner crust which presents strong inhomogeneities. These so-called clusters are bathing in a dilute neutron gas. Because of the low temperature, the neutron gas is superfluid and presents a Goldstone mode which we described within the Quasi-Particle Random Phase Approximation (QRPA) framework. In addition, the neutron gas is in equilibrium with the nuclear clusters made of neutrons and protons. We describe this equilibrium with a simple thermodynamics framework, and a more complete Extended Thomas-Fermi (ETF) formalism. The ETF formalism gives informations about geometrical and chemical properties of the crust. Our goal is to use them as input for a full description of the inner crust collective mode. Using the hydrodynamics framework, we are able to determine dynamic properties (entrainment) of neutron and proton components, even in complex geometries (cubic centred lattice, hexagonal, etc...).

Coordinate: mercoledì 25 novembre, ore 16:00, aula F