The braneworld theory states that in order for the universe to have survived, it would have had to create relatively small "black holes". Moreover, this theory can be experimented upon.
This theory suggests that we are in a three dimensional membrane that exist inside the bulk or the higher dimensional space.
In the case of the Randall-Sundrum model, such tests could involve measuring the gravitational waves that are emitted by the black holes thus linking one brane to another.
The Big Splat also known as the Ekpyrotic Theory, was thought of by cosmologists Neil Turok and Paul Steinhardt who believe that eventually a brane would collide with another and through the collision there will be enough energy to create a whole new universe.
The term "ekpyrotic" came from the word ekpyrosis which means conflagration in Greek.