  In this paper we use the conventional quantum hydrodynamics (QHD) model in
combination with the Sagdeev pseudopotential method to explore the effects of
Thomas-Fermi nonuniform electron distribution, Coulomb interactions, electron
exchange and ion correlation on the large-amplitude nonlinear soliton dynamics
in Fermi-Dirac plasmas. It is found that in the presence of strong interactions
significant differences in nonlinear wave dynamics of Fermi-Dirac plasmas in
the two distinct regimes of nonrelativistic and relativistic degeneracies
exist. Furthermore, it is remarked that first-order corrections due to such
interactions (which are proportional to the fine-structure constant) are
significant on soliton dynamics in nonrelativistic plasma degeneracy regime
rather than relativistic one. In the relativistic degeneracy regime, however,
these effects become less important and the electron quantum-tunneling and
Pauli-exclusion dominate the nonlinear wave dynamics. Hence, application of
non-interacting Fermi-Dirac QHD model to study the nonlinear wave dynamics in
quantum plasmas such as compact stars is most appropriate for the relativistic
degeneracy regime.
