Toward de Sitter space from ten dimensions

Abstract

Using a 10D lift of nonperturbative volume stabilization in type IIB string theory, we study the limitations for obtaining de Sitter vacua. Based on this we find that the simplest Kachru, Kallosh, Linde, and Trivedi vacua with a single Kähler modulus stabilized by a gaugino condensate cannot be uplifted to de Sitter. Rather, the uplift flattens out due to stronger backreaction on the volume modulus than has previously been anticipated, resulting in vacua which are metastable and supersymmetry breaking, but that are always anti-de Sitter (AdS). However, we also show that setups such as racetrack stabilization can avoid this issue. In these models it is possible to obtain supersymmetric AdS vacua with a cosmological constant that can be tuned to zero while retaining finite moduli stabilization. In this regime, it seems that de Sitter uplifts are possible with negligible backreaction on the internal volume. We exhibit this behavior also from the 10D perspective.

On uplifts by warped anti‐D3‐branes

“…By doing so, one may for instance match the known scalar potential for mobile D 3‐brane moduli that are induced by gaugino condensation. Moreover, the SUSY condition can be rediscovered in ten dimensions . To us the evidence is convincing enough to believe that a ten dimensional description of KKLT vacua in the spirit of [] is consistent.…”

De Sitter vs Quintessence in String Theory

“…In an effort to have a 10D description of gaugino condensation, ref. [] developed a technique to compute the contribution of the anti‐brane to the scalar potential and found no dS solution. This was understood also from the 4D EFT in terms of the nilpotent superfield X by considering the X dependence of W as: It is easy to check that for and the contribution of X to the scalar potential is such that there is no dS vacuum either in KKLT or in LVS…”

“…Also in the absence of non‐perturbative effects it is known that . Furthermore the analysis in [] does not include the case of Euclidean D3‐instanton contributions to the scalar potential. The proposal presented in [] to obtain dS by considering a racetrack scenario, while possible, has not been implemented in concrete models and may be difficult to construct without fine‐tuning coefficients of the non‐perturbative terms.…”

Towards an explicit model of large field inflation

“…This proof does not directly apply to time dependent backgrounds, or to the LVS stabilization mechanism we use, and therefore it presents no immediate obstacle to our model. However, by showing that, in the case of a single Kähler modulus, the antibrane uplift does not simply add to the Kähler moduli potential, [20] invites serious reservations as to the accuracy of all de Sitter constructions using antibranes. A better understanding of the positive energy added by antibranes in time dependent backgrounds with multiple Kähler moduli would certainly benefit the string cosmology community and be extremely relevant to this model.…”

“…Finally, it is necessary to mention some important caveats to this work, and the construction of positive vacuum energy solutions in string theory in general. First, recent work [20] has shown that the antibrane uplift in the KKLT [21] construction of de Sitter vacua with a single Kähler modulus is not sufficient to achieve positive vacuum energy. This proof does not directly apply to time dependent backgrounds, or to the LVS stabilization mechanism we use, and therefore it presents no immediate obstacle to our model.…”