Symmetry Energy, Tensor Force and Maximum Rotational Frequency of Neutron Stars

Description In the first part of this talk, I analyze the contribution of the different terms of the nucleon-nucleon interaction to the nuclear symmetry energy Esym and the slope parameter L . The analysis will be performed with the help of the  Hellmann--Feynman theorem within the microscopic Brueckner-Hartree-Fock (BHF) approach using realistic two- and three-nucleon forces. I will show that the main contribution to Esym and L comes from the tensor component of the nuclear force.
In the second part, I will study the role of the slope parameter L on the r-mode instability of neutron stars. To such end, I will use different models for the nuclear EoS that include the microscopic BHF, the variational Akmal--Pandharipande--Ravenhall (APR) EoS, a parametrization of recent Auxiliary Field Diffusion Monte Carlo (AFDMC) calculations, and several phenomenological Skyrme forces and relativistic mean field models. I consider both bulk ($\xi$) and shear ($\eta$) viscosities as the main dissipative mechanism of r-modes, including in the calculation of $\xi$ the contribution of the modified and direct electron and muon Urca processes and, in that of $\eta$, the contribution of neutron and electron scattering.