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arXiv · 2609.33452

Dimensional (In)dependence of Lorentzian Quantum Cosmology

Masazumi Honda·Hiroki Matsui·Kota Numajiri·Kazumasa Okabayashi·Takahiro Terada
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Abstract

We study transition amplitudes of the quantum universe in $D$-dimensional spacetime within the de Sitter minisuperspace approximation in Einstein gravity. Using the Lorentzian path integral combined with Picard-Lefschetz theory, we identify the saddle points that contribute to the integral and derive a well-defined transition amplitude under Dirichlet boundary conditions. We further show numerically that a resurgence analysis based on Borel-Padé resummation is effective in resolving the residual Stokes ambiguities that arise in certain cases. Analyzing three-, four-, and five-dimensional cases, as well as the large-$D$ limit, we find that the tunneling proposal is commonly realized for the creation of the universe from nothing. This result implies a universal feature of quantum cosmology based on Einstein gravity across dimensions.

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Masazumi Honda, Hiroki Matsui, Kota Numajiri, Kazumasa Okabayashi, Takahiro Terada. 2026-09-27. Dimensional (In)dependence of Lorentzian Quantum Cosmology. https://arxiv.org/abs/2609.33452

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