Unitarity constraint on the K\"ahler curvature

Understand

In supersymmetric theories, the signs of quartic terms in the K\"ahler potential control the stability of non-supersymmetric field configurations.

• In particular, in supersymmetric inflation models, the signs are important for the stability of an inflationary trajectory as well as for the prediction of the spectral index.
• In this paper, we clarify what properties of a UV theory determine the sign from unitarity arguments of scattering amplitudes.
• As non-trivial examples, we discuss the sign of a four-meson term in large $N$ supersymmetric gauge theories and also those of the quartic terms obtained in the intersecting D-brane models in superstring theory.