Our everyday experiences tells us we live in a 3+1 dimensional world. What if we were like ink drops stuck in a sheet of paper ? There would be one or more extradimensions that we don’t see but that can have an effect on the paper, like curving, bending or stretching it. On another hand, String Theory predicts more than 4 dimensions. Higher dimensional gravity is a phenomenological description if low energy String Theory. However, these models need to be consistent with our everyday experience. This is where the branes appear; branes are the 3+1 dimensional sheets that we live in, embedded in a bulk extradimensional space.
My research in this direction consists in studying brane model with an extension in the extradimensions and how they localize matter fields. In particular, these brane can include a (positive) cosmological constant.