  As a result of non-linear self-interactions, in chameleon theories where the
field couples to matter much more strongly than gravity does, the fifth force
between two bodies with thin-shell is independent of their coupling to the
field. As a consequence the bounds on the coupling coming from terrestrial
tests of gravity, measurements of the Casimir force and those constraints
imposed by the physics of compact objects, big-bang nucleosynthesis and
measurements of the cosmic microwave background anisotropies can be
exponentially relaxed.
