Key points are not available for this paper at this time.
It is shown that the Virasoro-Shapiro model contains Einstein's theory of gravity as a zero-slope limit. It is also shown that the conventional dual model contains the scalar electrodynamics as a zero-slope limit. The connection between the generating functionals for the scattering matrices of these dual models and the corresponding field theories is demonstrated.
Tamiaki Yoneya (1974) studied this question.