Topic
String theory landscape
About: String theory landscape is a research topic. Over the lifetime, 224 publications have been published within this topic receiving 21971 citations. The topic is also known as: landscape of string theory vacua & landscape of string theory.
Papers published on a yearly basis
Papers
TL;DR: The metastable de Sitter vacua of type IIB string theory has been constructed in this article, which is a supersymmetric version of the ground state of the original ground state.
Abstract: We outline the construction of metastable de Sitter vacua of type IIB string theory. Our starting point is highly warped IIB compactifications with nontrivial NS and RR three-form fluxes. By incorporating known corrections to the superpotential from Euclidean D-brane instantons or gaugino condensation, one can make models with all moduli fixed, yielding a supersymmetric AdS vacuum. Inclusion of a small number of $\overline{\mathrm{D}3}$-branes in the resulting warped geometry allows one to uplift the AdS minimum and make it a metastable de Sitter ground state. The lifetime of our metastable de Sitter vacua is much greater than the cosmological time scale of ${10}^{10}\mathrm{yr}.$ We also prove, under certain conditions, that the lifetime of dS space in string theory will always be shorter than the recurrence time.
4,791 citations
TL;DR: In this article, the authors show that the hierarchy of scales can be fixed by a choice of Ramond-Ramond and Neveu-Schwarz fluxes in the compact manifold, and give examples involving orientifold compactifications of type IIB string theory and F-theory compactifications on Calabi-Yau fourfolds.
Abstract: Warped compactifications with significant warping provide one of the few known mechanisms for naturally generating large hierarchies of physical scales. We demonstrate that this mechanism is realizable in string theory, and give examples involving orientifold compactifications of type-IIB string theory and F-theory compactifications on Calabi-Yau fourfolds. In each case, the hierarchy of scales is fixed by a choice of Ramond-Ramond and Neveu-Schwarz fluxes in the compact manifold. Our solutions involve compactifications of the Klebanov-Strassler gravity dual to a confining $\mathcal{N}=1$ supersymmetric gauge theory, and the hierarchy reflects the small scale of chiral symmetry breaking in the dual gauge theory.
2,965 citations
TL;DR: In this article, it was shown that with multiple fluxes the allowed values can form a sufficiently dense ''discretuum'' for M-theory compactifications on manifolds with non-trivial three-cycles.
Abstract: A four-form gauge flux makes a variable contribution to the cosmological constant. This has often been assumed to take continuous values, but we argue that it has a generalized Dirac quantization condition. For a single flux the steps are much larger than the observational limit, but we show that with multiple fluxes the allowed values can form a sufficiently dense `discretuum'. Multiple fluxes generally arise in M-theory compactifications on manifolds with non-trivial three-cycles. In theories with large extra dimensions a few four-forms suffice; otherwise of order 100 are needed. Starting from generic initial conditions, the repeated nucleation of membranes dynamically generates regions with λ in the observational range. Entropy and density perturbations can be produced.
1,747 citations
TL;DR: It is argued here that in universes that do not recollapse, the only bound on the cosmological constantlambda is that it should not be so large as to prevent the formation of gravitationally bound states, and it turns out that the bound is quite large.
Abstract: In recent cosmological models, there is an "anthropic" upper bound on the cosmological constant $\ensuremath{\Lambda}$. It is argued here that in universes that do not recollapse, the only such bound on $\ensuremath{\Lambda}$ is that it should not be so large as to prevent the formation of gravitationally bound states. It turns out that the bound is quite large. A cosmological constant that is within 1 or 2 orders of magnitude of its upper bound would help with the missing-mass and age problems, but may be ruled out by galaxy number counts. If so, we may conclude that anthropic considerations do not explain the smallness of the cosmological constant.
1,381 citations
TL;DR: In this paper, the authors studied the large volume limit of the scalar potential in Calabi-Yau flux compactifications of type IIB string theory, and they showed that there exists a limit in which the potential approaches zero from below, with an associated non-supersymmetric AdS minimum at exponentially large volume.
Abstract: We study the large volume limit of the scalar potential in Calabi-Yau flux compactifications of type IIB string theory. Under general circumstances there exists a limit in which the potential approaches zero from below, with an associated non-supersymmetric AdS minimum at exponentially large volume. Both this and its de Sitter uplift are tachyon-free, thereby fixing all K?hler and complex structure moduli. Also, for the class of vacua described in this paper, the gravitino mass is independent of the flux discretuum, whereas the ratio of the string scale to the 4d Planck scale is hierarchically small but flux dependent. The inclusion of ?' corrections plays a crucial role in the structure of the potential. We illustrate these ideas through explicit computations for a particular Calabi-Yau manifold.
1,347 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 9 |
| 2019 | 14 |
| 2018 | 2 |
| 2017 | 4 |
| 2016 | 4 |