This review demonstrates that neutrino emission from dense hadronic component
in neutron stars is subject of strong modifications due to collective effects
in the nuclear matter. With the most important in-medium processes incorporated
in the cooling code an overall agreement with available soft X ray data can be
easily achieved. With these findings so called "standard" and "non-standard"
cooling scenarios are replaced by one general "nuclear medium cooling scenario"
which relates slow and rapid neutron star coolings to the star masses (interior
densities). In-medium effects take important part also at early hot stage of
neutron star evolution decreasing the neutrino opacity for less massive and
increasing for more massive neutron stars. A formalism for calculation of
neutrino radiation from nuclear matter is presented that treats on equal
footing one-nucleon and multiple-nucleon processes as well as reactions with
resonance bosons and condensates. Cooling history of neutron stars with quark
cores is also discussed.Comment: To be published in "Physics of Neutron Star Interiors", Eds. D.
Blaschke, N.K. Glendenning, A. Sedrakian, Springer, Heidelberg (2001