Realisation of de Sitter space as an excited state in string theory
Abstract
String theory is widely regarded as the only plausible candidate for a consistent UV-complete theory of quantum gravity. Cosmological observations suggest that our universe is undergoing accelerated expansion, pointing towards the presence of a small positive cosmological constant. Since de Sitter space is the maximally symmetric solution of Einstein's equations with a positive cosmological constant, understanding whether four-dimensional de Sitter space can be realized within string theory has become one of the central questions. Following a series of works that realize de Sitter space as an excited state---namely, as a Glauber--Sudarshan (GS) state in type IIB string theory---our goal has been to extend such a construction to heterotic string theories. Realizing de Sitter space as an excited state over a time-independent supersymmetric Minkowski background provides a mechanism for evading the vacuum-based no-go theorems that obstruct de Sitter solutions in string theory. Starting from a generic M-theory configuration, we obtain four-dimensional de Sitter space in the late-time limit of flat-slicing coordinates in both heterotic SO(32) and heterotic E8 × E8 theories through appropriate dynamical duality sequences. The corresponding GS state is constructed by evaluating the expectation value of the metric operator in M-theory using path-integral techniques. We analyse the conditions required for the existence of a well-defined effective field theory description of the setup and find that these conditions are equivalent to satisfying the null energy condition in a 3+1-dimensional FLRW cosmology. Furthermore, the de Sitter GS states are found to lie well within the temporal bound imposed by the Trans-Planckian Censorship Conjecture, rendering them as transient states. In the case of E8× E8 theory, we also investigate implications arising from axion cosmology.
Related
- De Sitter in string theory vs. Gibbons & Hawking
- Nonlinear Higher-Spin Theory in O(4,1) de Sitter Space
- On the analytic continuation and asymptotic behaviour of the two-point function in massless ϕ4-theory in Euclidean de Sitter space
- Soliton like solutions of λϕ4 theory in de Sitter space
- Boundary Conditions and Entanglement in Anti-de Sitter Space
BibTeX
@misc{maji2026realisation,
title = {{Realisation of de Sitter space as an excited state in string theory}},
author = {Archana Maji},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20301},
eprint = {2610.20301},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.20301},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Realisation of de Sitter space as an excited state in string theory
AU - Archana Maji
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2610.20301
UR - https://arxiv.org/abs/2610.20301
AB - String theory is widely regarded as the only plausible candidate for a consistent UV-complete theory of quantum gravity. Cosmological observations suggest that our universe is undergoing accelerated expansion, pointing towards the presence of a small positive cosmological constant. Since de Sitter space is the maximally symmetric solution of Einstein's equations with a positive cosmological constant, understanding whether four-dimensional de Sitter space can be realized within string theory has become one of the central questions. Following a series of works that realize de Sitter space as an excited state---namely, as a Glauber--Sudarshan (GS) state in type IIB string theory---our goal has been to extend such a construction to heterotic string theories. Realizing de Sitter space as an excited state over a time-independent supersymmetric Minkowski background provides a mechanism for evading the vacuum-based no-go theorems that obstruct de Sitter solutions in string theory. Starting from a generic M-theory configuration, we obtain four-dimensional de Sitter space in the late-time limit of flat-slicing coordinates in both heterotic SO(32) and heterotic E_8 × E_8 theories through appropriate dynamical duality sequences. The corresponding GS state is constructed by evaluating the expectation value of the metric operator in M-theory using path-integral techniques. We analyse the conditions required for the existence of a well-defined effective field theory description of the setup and find that these conditions are equivalent to satisfying the null energy condition in a 3+1-dimensional FLRW cosmology. Furthermore, the de Sitter GS states are found to lie well within the temporal bound imposed by the Trans-Planckian Censorship Conjecture, rendering them as transient states. In the case of E_8× E_8 theory, we also investigate implications arising from axion cosmology.
ER -