Three non-linear ways of testing modified gravity
We can measure dark energy, but we do not know what it is or where it comes from. One possible explanation is based in modifications to Einstein's theory for gravity. The literature provides several alternative models that were designed for this purpose. The next step after proposing these models consists in finding new ways of differentiating between them using observable quantities. I will present three different ways in which this can be done, which are based in the non-linear regime of cosmological evolution.