Brane-world models emerging from collisions of plane waves in 5D (Q1878332)

The author considers cosmological brane-world models in 5-dimensional bulks with signatures \((+---+)\) and \((+----)\). It is shown that the generalized Friedman equations give rise to effective 4-dimensional behaviors corresponding to a big-bang (case of space-like extra dimension), or to a big-bounce (time-like extra dimension). The 4-branes are identified as the collision of some waves propagating in opposite directions along the extra dimension. It is argued that such results should be independent of the bulk details.