Raising Anti de Sitter Vacua to de Sitter Vacua in Heterotic M-Theory
Evgeny I. Buchbinder
TL;DR
This work addresses constructing metastable de Sitter vacua in strongly coupled heterotic string theory by adapting KKLT-like moduli stabilization. It analyzes two lifting mechanisms: (i) Fayet-Iliopoulos terms from anomalous U(1) factors, which generate a positive $U_D$ that can uplift an AdS minimum to de Sitter when balanced against the supergravity potential, and (ii) globally universal corrections from anti five-branes in the bulk (or $E_8 \times \bar{E}_8$), which yield a moduli-dependent $\Delta U$ with similar qualitative behavior but potentially large overall scale. In a simplified three-modulus setup, the authors show that a dS minimum with a tunable cosmological constant $\Lambda$ is achievable for suitable choices of $W_f$, FI parameters, and moduli values; they also discuss the constraints and challenges posed by many moduli and the need to stabilize some Kahler moduli at scales below the Calabi-Yau scale. The results provide a heterotic analogue of KKLT and illuminate the crucial roles of five-branes and FI terms in realizing realistic vacua, while highlighting the remaining hurdles in achieving universally small $\Lambda$ across generic compactifications.
Abstract
We explore the possibility of obtaining de Sitter vacua in strongly coupled heterotic models by adding various corrections to the supergravity potential energy. We show that, in a generic compactification scenario, Fayet-Iliopoulos terms can generate a de Sitter vacuum. The cosmological constant in this vacuum can be fine tuned to be consistent with observation. We also study moduli potentials in non-supersymmetric compactifications of $E_8 \times E_8$ theory with anti five-branes and $E_8 \times \bar E_8$ theory. We argue that they can be used to create a de Sitter vacuum only if some of the Kahler structure moduli are stabilized at values much less than the Calabi-Yau scale.