The general behavior of the nuclear equation of state (EOS), relevant for the
description of neutron stars (NS), is studied within a relativistic mean field
description of nuclear matter. Different formulations, both with density
dependent couplings and with non-linear mesonic terms, are considered and their
predictions compared and discussed. A special attention is drawn to the effect
on the neutron star properties of the inclusion of exotic degrees of freedom as
hyperons. Properties such as the speed of sound, the trace anomaly, the proton
fraction and the onset of direct Urca processes inside neutron stars are
discussed. The knowledge of the general behavior of the hadronic equation of
state and the implication it has on the neutron star properties will allow to
identify signatures of a deconfinement phase transition discussed in other
studies.Comment: 16 pages, 11 figure