Aspects of Brane Physics in 5 and 6 Dimensions

We outline a general strategy to deal with perturbations in brane world models. We illustrate the method by studying simple 6D brane world compactifications. We introduce the background geometries induced by the branes, and summarize the main physical features observed in the fluctuation spectra. We compare these results with 5D brane world models and the traditional Kaluza-Klein picture.