The effects of a non-zero cosmological constant on the Veltmann models
  The Veltmann models, which include the Plummer and Hernquist models as
special cases, are studied in the presence of a cosmological constant.
Physically relevant quantities such as the velocity dispersion profiles and the
anisotropy parameter are computed through the use of the self-consistent
approach. The cutoff radii for these models and the mass contained within this
volume are also calculated. It is shown that the inclusion of a cosmological
constant leads to many observable quantities such as the surface density,
dispersion profiles and the anisotropy parameter becoming increasingly
modified. In some scenarios, they are easily distinguished from the case where
the cosmological constant is absent, as a result of their non-monotonic
behaviour. The effects of neighbouring gravitational systems on the central
system are also studied, and compared against the effects arising from the
cosmological constant. Consequently, it is suggested that the effects of a
cosmological constant can prove to be quite important when modelling dilute
collisionless systems.
