Hi,

 

I was wondering how a brane could expand to universal proportions, because wouldn't there be dissipation of some sort, stretching and instability.

Good question,

 

I found this article,

 

http://iopscience.iop.org/1126-6708/2003/12/012/pdf/1126-6708_2003_12_012.pdf

 

It is a pdf so you will have to download it.

 

Essentially though, the important part that answers your question, is that multiple p-branes may exist in a given M5-brane (a intertwined sea of multiple p-branes). A brane's energy is proportional to the inverse of its volume. So, whether the branes are compact or expanded, the result of an expanding universe in such a scenario is the same.

 

An expanding universe will eventually end as a compacting universe. Of course there may be conflicting articles out there, M-theory like all string theories are relatively young, with varying interpretations.