Control Problem of de Sitter Vacua with T-brane Uplift
Abstract
T-branes have been argued to provide a consistent uplift to de Sitter vacua in the context of the LARGE-volume scenario of type IIB string theory. We point out that this construction suffers from a serious control problem: the string-frame volume is bounded from above by a number that depends only on the topology of the Calabi-Yau orientifold and is often 𝒪(1) or smaller. This observation immediately rules out controlled de Sitter vacua in many models with h1,1=2 if the non-perturbative superpotential is generated by D3-brane instantons. We give evidence that similar conclusions apply for h1,1>2 and show this explicitly for two models with h1,1=4. Our volume bound is seemingly less severe in models where the non-perturbative superpotential is generated by gaugino condensation. However, we study 𝒪(600) such models and find that, although de Sitter solutions with large volumes are naively possible there, they suffer from uncontrolled warping corrections whose volume suppression is cancelled by other factors, in particular large charges. We also observe that the models with the smallest warping corrections within our set have very small tadpoles and at the same time require a fine-tuned string coupling and flux superpotential, which may indicate an additional problem with the axio-dilaton/complex-structure-moduli stabilization. Finally, we point out an independent challenge related to the stabilization of the brane moduli. Our various results lead us to conclude that it is unlikely that the scenario of T-brane uplifting can be realized in string theory in a self-consistent manner.
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BibTeX
@misc{junghans2026control,
title = {{Control Problem of de Sitter Vacua with T-brane Uplift}},
author = {Daniel Junghans},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.35985},
eprint = {2609.35985},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.35985},
}
RIS
TY - UNPB
TI - Control Problem of de Sitter Vacua with T-brane Uplift
AU - Daniel Junghans
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.35985
UR - https://arxiv.org/abs/2609.35985
AB - T-branes have been argued to provide a consistent uplift to de Sitter vacua in the context of the LARGE-volume scenario of type IIB string theory. We point out that this construction suffers from a serious control problem: the string-frame volume is bounded from above by a number that depends only on the topology of the Calabi-Yau orientifold and is often 𝒪(1) or smaller. This observation immediately rules out controlled de Sitter vacua in many models with h^1,1=2 if the non-perturbative superpotential is generated by D3-brane instantons. We give evidence that similar conclusions apply for h^1,1>2 and show this explicitly for two models with h^1,1=4. Our volume bound is seemingly less severe in models where the non-perturbative superpotential is generated by gaugino condensation. However, we study 𝒪(600) such models and find that, although de Sitter solutions with large volumes are naively possible there, they suffer from uncontrolled warping corrections whose volume suppression is cancelled by other factors, in particular large charges. We also observe that the models with the smallest warping corrections within our set have very small tadpoles and at the same time require a fine-tuned string coupling and flux superpotential, which may indicate an additional problem with the axio-dilaton/complex-structure-moduli stabilization. Finally, we point out an independent challenge related to the stabilization of the brane moduli. Our various results lead us to conclude that it is unlikely that the scenario of T-brane uplifting can be realized in string theory in a self-consistent manner.
ER -