Abstract
The modifications of the classical equations of motion of the gravitational field in type II string theory are derived by studying tree-level gravitational scattering amplitudes. The effective gravitational action is determined through quartic order in the Riemann tensor. It is shown that generic Ricci-flat manifolds do not solve the modified equations, unless in addition the manifolds are Kähler (2 N-dimensional manifolds of SU(N) holonomy). Translated into sigma model language, this calculation would indicate that the N = 1 supersymmetric sigma model in 2 dimensions, with a Ricci-flat target space, is not conformally invariant, but has a nonzero beta function at four-loop order.
Original language | English (US) |
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Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | Nuclear Physics, Section B |
Volume | 277 |
Issue number | C |
DOIs | |
State | Published - 1986 |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics