The influence of non-minimally coupled scalar fields on the dynamics of interacting galaxies

We study bar formation in galactic disks as a consequence of the collision of two spiral galaxies under the influence of a potential which is obtained from the Newtonian limit of a scalar--tensor theory of gravity. We found that dynamical effects depend on parameters ($\alpha$, $\lambda$) of the theory. In particular, we observe that the bar is shorter for weaker tidal perturbations, which in turn corresponds to smaller values of $\lambda$ used in our numerical experiments.