String theory and the KLT-relations between gravity and gauge theory including external matter

N. E. J. Bjerrum-Bohr, K. Risager

Published 2004-07-12, updated 2004-09-28Version 3

We consider the Kawai-Lewellen-Tye (KLT) factorizations of gravity scalar-leg amplitudes into products of scalar-leg Yang-Mills amplitudes. We check and examine the factorizations at O(1) in $\alpha'$ and extend the analysis by considering KLT-mapping in the case of generic effective Lagrangians for Yang-Mills theory and gravity.