What is the current mathematical formulation of M theory?

[twistor]

Which is the current mathematical formulation of M theory, and what are its competitors?

 

[twistor]

Is there anyone intersted in M theory?

 

[andrien]

There is no basic notion of M-theory ,it only exist as a low energy supergravity.Just to support the renormalizability,we extend it in higher energy regime calling M theory.And doing some compactification on a line or circle to give rise to different string theory and then using duality to relate one with another like IIA to IIB.