The string wave function across a Kasner singularity

Understand

A collision of orbifold planes in eleven dimensions has been proposed as an explanation of the hot big bang.

• When the two planes are close to each other, the winding membranes become the lightest modes of the theory, and can be effectively described in terms of fundamental strings in a ten dimensional background.
• Near the brane collision, the eleven-dimensional metric is an Euclidean space times a 1+1-dimensional Milne universe.
• However, one may expect small perturbations to lead into a more general Kasner background.