  A novel method of transplanting algebras of observables from de Sitter space
to a large class of Robertson-Walker space-times is exhibited. It allows one to
establish the existence of an abundance of local nets on these spaces which
comply with a recently proposed condition of geometric modular action. The
corresponding modular symmetry groups appearing in these examples also satisfy
a condition of modular stability, which has been suggested as a substitute for
the requirement of positivity of the energy in Minkowski space. Moreover, they
exemplify the conjecture that the modular symmetry groups are generically
larger than the isometry and conformal groups of the underlying space-times.
