the conformal representation and not make sweeping statements. Certain points have been raised in the literature which either constitute a problem for Dicke’s view, or, at least, indicate that this viewpoint cannot be applied blindly, including the following ones.

For example, massive particles follow time-like geodesics in the Jordan frame, while they deviate from geodesic motion in the Einstein frame due to a force proportional to the gradient of the conformal scalar field [@FaraoniNadeauconfo]. Hence, the Weak Equivalence Principle is satisfied only in the Jordan frame but not in the Einstein frame due to the coupling of the scalar field to the ordinary matter. Since the Equivalence Principle is the foundation of any relativistic theory of gravity, this aspect is important and there are two ways to consider it. One can ask for the two conformal frames are equivalent also with respect to the Equivalence Principle. This means that Equivalence Principle is formulated in a way that depends on the conformal frame representation. Then, a representation-independent formulation must be sought for. However, up to now, no definite result exists in this direction. On the other hand, we can ask for the violation of the Weak Equivalence Principle in the Einstein 