On the Vainshtein mechanism for two body system in DGP model
Hiramatsu, Takashi (Yukawa Institute for Theoretical Physics, Kyoto University)

We study the Vainshtein mechanism for a two-body system like the Earth-Moon system in the DGP model. It is well known that the dynamical scalar d.o.f. in the model, so-called the brane-bending mode, plays an important role on the orbit of a bounded system, for example, the precession of the Moon orbit around the Earth predicted in GR is modified. However, in such stdies so far, we have not considered the strong non-linear interaction of the scalar field around the objects, which promotes to recover GR around the objects (the Vainshtein mechanism). In our presentation, we show that the effect of a small object (like the Moon) around a massive object (like the Earth) cannot be treated in a perturbative way, and thus the observational predictions we have known so far may be corrected.