De Sitter String Vacua from Dilaton-dependent Non-perturbative Effects

TL;DR

This paper introduces a new method for stabilizing moduli in type IIB string compactifications using dilaton-dependent non-perturbative effects, enabling de Sitter vacua with a supersymmetric uplift, broadening the LVS applicability.

Contribution

It proposes a novel moduli stabilization mechanism using dilaton-dependent effects, providing a supersymmetric uplift to de Sitter vacua within the LVS framework.

Findings

Dilaton-dependent effects contribute positively to the scalar potential.

The mechanism allows for de Sitter vacua without anti D3-branes.

LVS can be realized for manifolds with zero or positive Euler number.

Abstract

We consider a novel scenario for modulus stabilisation in IIB string compactifications in which the Kahler moduli are stabilised by a general set-up with two kinds of non-perturbative effects: (i) standard Kahler moduli-dependent non-perturbative effects from gaugino condensation on D7-branes or E3-instantons wrapping four-cycles in the geometric regime; (ii) dilaton-dependent non-perturbative effects from gaugino condensation on space-time filling D3-branes or E(-1)-instantons at singularities. For the LARGE Volume Scenario (LVS), the new dilaton-dependent non-perturbative effects provide a positive definite contribution to the scalar potential that can be arbitrarily tuned from fluxes to give rise to de Sitter vacua. Contrary to anti D3-branes at warped throats, this term arises from a manifestly supersymmetric effective action. In this new scenario the "uplifting" term comes from F-terms of blow-up modes resolving the singularity of the non-perturbative quiver. We discuss phenomenological and cosmological implications of this mechanism. This set-up also allows a realisation of the LVS for manifolds with zero or positive Euler number.