Brane cosmology without string theory?

[Suekdccia]

TL;DR

Are there models of brane cosmology which are not necessarily or directly related to string theory?

There are several models of brane cosmology (https://en.wikipedia.org/wiki/Brane_cosmology) and several physicists working in this field (e.g Lisa Randall and Raman Sundrum), but as you will notice, apparently they are all directly related to string theory. This has several consequences, for example, the "brane-worlds" in these theories cannot exceed the maximum number of dimensions that string theory allows (for example, in M-theory, which is closely related to string theory, branes cannot exceed 11 dimensions). Also these "brane-worlds" could have different laws of physics, but all of them would follow the fundamental laws of string theory.

Therefore, is there any model or physicist working on this field who proposes a "brane-world" cosmological scenario where the branes could have any number of dimensions (even infinitely many) and different fundamental laws of physics?

 

[haushofer]

I guess one of the things brane scenarios are investigating, is the nature of the big bang singularity or hierarchy problems. For that you need quantum gravity, and string theory provides you with such a framework.

I'm not sure how interesting an arbitrary classical brane scenario would be, which for me explains why I can't think of such scenarios. But maybe I'm just ignorant :P