Calculable e^{{1}/{λ}} effects
Abstract
We identify and evaluate a class of physical amplitudes in fourdimensional N = 4 superstring theory, which receive, in the weakcoupling limit, contributions of order e^{{1}/{λ}}, where λ is the type II superstring coupling constant. They correspond to fourderivative overlineF_{1} interaction terms involving the universal type II dilaton supermultiplet. The exact results, obtained by means of a oneloop computation in the dual heterotic theory compactified on ⊤ ^{6}, is compared with the perturbation theory on the type II side, and the e^{{1}/{λ}} contributions are associated to nonperturbative effects of Euclidean solitons (Dbranes) wrapped on K3 × ⊤ ^{2}. The tendimensional decompactification limit on the type IIB side validates the recent conjecture for the Dinstantoninduced R^{4} couplings.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1998
 DOI:
 10.1016/S05503213(97)006846
 arXiv:
 arXiv:hepth/9707222
 Bibcode:
 1998NuPhB.512...61A
 Keywords:

 High Energy Physics  Theory
 EPrint:
 LaTex, 24 pages