26-dimensional string from 4-dimensional geometry (Q1101719)

A study of 4-dimensional volume preserving covariant changes of the metric leads directly to string theory in 26 dimensions. In any conformally invariant theory of such metric distortion, a new principle of relativity is shown to imply that the maximum number of independent components of the distortion tensor is 26. Within the simplest such theory allowing metric compatible spaces as trivial solutions, we show that this maximum is realized by a solution equivalent to the 26- dimensional bosonic string.