Modern theoretical physics seems to be focused heavily on string theory while it is a very rewarding area of physics which will no doubt help provide us with a much deeper understanding of our universe. However or should other possibilities for the combination of Quantum Gravity with general relativity into one theory that functions not only in the tiny quantum world, but also in the macroscopic world of general relativity.

There are many reasons why string theory is the focus of more research than other areas many of the political, which I do not intend to go into. The reason why I find deformed special relativity so appealing is largely due to the premise of Occam's razor, simply stating that the simplest solution is normally the correct one.

The reason why I feel that this is applicable to Deformed Special Relativity, is that DSR does not require the existence of extra compacted dimensions in addition to the four easily detectable macroscopic ones. String theory relies upon tight control of physical constants and the properties of extra dimensions in its attempts to unite quantum gravity and general relativity. DSR however simply alters Einstein general relativity slightly by constructing itself entirely from Lorentz groups rather than partially from Lorentz and partially from Newtonian groups.

The main difficulty in uniting General Relativity and Quantum gravity is essentially dependent upon the fact that in Quantum Mechanics the Planck length (the minimum length corresponding to detail that can be resolved due to the uncertainty principle) must be completely invariant, whereas in general relativity its

Special relativities basic premise is that no objects velocity can exceed that of light , but DSR's altered beginnings in Lorentz groups mean that it's premises are that no object's velocity can exceed that of light and also that no length can contract (appear shorter to an observer, depending on the observer's velocity), to a length shorter than that of Planck length.

I believe that this limit it places upon length will allow for it to unite quantum mechanics and gravity into one mathematical treatment applicable on all scales, however the difficulty emerges from the fact that no one has yet come up wit ha generalized form of DSR that would allow for it to interpret gravity, as special relativities do not account for acceleration, this is small step it took Einstein ten years to create a general relativity from his specialized form.

For a more technical discussion.