Conformal Transformations and Weak Field Limit of Scalar-Tensor Gravity

Understand

The weak field limit of scalar tensor theories of gravity is discussed in view of conformal transformations.

• Specifically, we consider how physical quantities, like gravitational potentials derived in the Newtonian approximation for the same scalar-tensor theory, behave in the Jordan and in the Einstein frame.
• The approach allows to discriminate features that are invariant under conformal transformations and gives contributions in the debate of selecting the true physical frame.
• As a particular example, the case of $f(R)$ gravity is considered.