Quadratic curvature corrections to stringy effective actions and the absence of de Sitter vacua

We investigate the combined effect of fluxes and higher-order curvature corrections, in the form of the Gauss-Bonnet term, on the existence of de Sitter vacua in a heterotic string inspired framework, compactified on spheres and tori. We first gain some intuition on the effects of these corrections by studying a perturbative expansion in the small Gauss-Bonnet coupling. Then, for choices of potential closer to the string theory predictions, we show that the inclusion of quadratic curvature corrections actually reduces the parametric likelihood of de Sitter solutions.

Automated summary

We investigate the combined effect of fluxes and higher-order curvature corrections on the existence of de Sitter vacua in a heterotic string inspired framework. By studying a perturbative expansion in the small Gauss-Bonnet coupling, we gain intuition on the effects of these corrections. We show that, for choices of potential closer to the string theory predictions, the inclusion of quadratic curvature corrections reduces the parametric likelihood of de Sitter solutions.