In brane-world theory in five dimensions, the bulk metric is usually written in gaussian coordinates, where g 4µ = 0 and g 44 = −1. However, the choice g 44 = −1 is not mandatory. The presence of matter in the brane can generate temporal and spatial variations of g 44 , which in turn backreact on the brane. In this paper we study the consequences of having g 44 = ǫΦ 2 , where ǫ = ±1 and Φ is a ...