  We consider a model for gravity that is invariant under global scale
transformations. It includes one extra real scalar field coupled non-minimally
to the gravity fields. In this model all the dimensionful parameters like the
gravitational constant and the cosmological constant etc. are generated by a
solution of the classical equations of motion which breaks scale invariance. In
this paper we demonstrate the stability of such a solution against small
perturbations in a flat FRW background by making a perturbative expansion
around this solution and solving the resulting equations linear in the
perturbations.

General Relativity and Quantum Cosmology