Neutrino emission, Equation of State and the role of strong gravity

Neutron-star mergers are interesting for several reasons: they are proposed as the progenitors of short gamma-ray bursts, they have been speculated to be a site for the synthesis of heavy elements, and they emit gravitational waves possibly detectable at terrestrial facilities. The understanding of the merger process, from the pre-merger stage to the final compact object-accreting system involves detailed knowledge of numerical relativity and nuclear physics. In particular, key ingredients for the evolution of the merger are neutrino physics and the matter equation of state. We present some aspects of neutrino emission from binary neutron star mergers showing the impact that the equation of state has on neutrinos and discuss some spectral quantities relevant to their detection such as energies and luminosities far from the source.Comment: 7 pages , 3 figures. XI LASNPA conference proceeding

Neutrinos and the synthesis of heavy elements: the role of gravity

The synthesis of heavy elements in the Universe presents several challenges. From one side the astrophysical site is still undetermined and on other hand the input from nuclear physics requires the knowledge of properties of exotic nuclei, some of them perhaps accessible in ion beam facilities. Black hole accretion disks have been proposed as possible r-process sites. Analogously to Supernovae these objects emit huge amounts of neutrinos. We discuss the neutrino emission from black hole accretion disks. In particular we show the influence that the black hole strong gravitational field has on changing the electron fraction relevant to the synthesis of elements.Comment: 5 pages, 5 figures, Invited talk at the 15th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS15), to appear in EPJ Web of Conference

Neutrino Scattering in Heterogeneous Supernova Plasmas

Neutrinos in core collapse supernovae are likely trapped by neutrino-nucleus elastic scattering. Using molecular dynamics simulations, we calculate neutrino mean free paths and ion-ion correlation functions for heterogeneous plasmas. Mean free paths are systematically shorter in plasmas containing a mixture of ions compared to a plasma composed of a single ion species. This is because neutrinos can scatter from concentration fluctuations. The dynamical response function of a heterogeneous plasma is found to have an extra peak at low energies describing the diffusion of concentration fluctuations. Our exact molecular dynamics results for the static structure factor reduce to the Debye Huckel approximation, but only in the limit of very low momentum transfers.Comment: 11 pages, 13 figure