When Braneworlds Collide

Sammanfattning: This project is an investigation of a cosmological model consisting of a five dimensional AdS-vacuum with a flux. By discharges in the flux, four dimensional bubbles can nucleate in the vacuum and collide with each other while expanding. Our observable universe is considered to be localized on the membrane of such a bubble. The main purpose of the model was to find a possible explanation for dark energy and inflation. We compute the Friedmann equation for an expanding bubble, as well as analytical expressions for the two slow roll parameters ε and η related to slow roll inflation. We also show that there exists a set of parameters of the model where both slow roll parameters are small enough in order for inflation to last for at least 60 Hubble times. However, our model doesn’t survive all consistency checks with today’s observations. We conclude that even if the resulting slow roll parameters look promising, one has to either look harder for a set of ”good” fundamental parameters of the model, or further develop it to have a chance of surviving all consistency checks.