  The in-medium properties of $D_S$ mesons are investigated within the
framework of an effective hadronic model, which is a generalization of a chiral
SU(3) model, to SU(4), in order to study the interactions of the charmed
hadrons. In the present work, the $D_s$ mesons are observed to experience net
attractive interactions in a dense hadronic medium, hence reducing the masses
of the $D_S^+$ and $D_S^-$ mesons from the vacuum values. While this conclusion
holds in both nuclear and hyperonic media, the magnitude of the mass drop is
observed to intensify with the inclusion of strangeness in the medium.
Additionally, in hyperonic medium, the mass degeneracy of the $D_S$ mesons is
observed to be broken, due to opposite signs of the Weinberg-Tomozawa
interaction term in the Lagrangian density. Along with the magnitude of the
mass drops, the mass splitting between $D_S^+$ and $D_S^-$ mesons is also
observed to grow with an increase in baryonic density and strangeness content
of the medium. However, all medium effects analyzed are found to be weakly
dependent on isospin asymmetry and temperature. We discuss the possible
implications emanating from this analysis, which are all expected to make a
significant difference to observables in heavy ion collision experiments,
especially the upcoming Compressed Baryonic Matter (CBM) experiment at the
future Facility for Antiproton and Ion Research (FAIR), GSI, where matter at
high baryonic densities is planned to be produced.
