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arXiv · 2509.09759

Bianchi-I cosmology with scale dependent $G$ and $\Lambda$ in asymptotically safe gravity

Chiang-Mei Chen·Akihiro Ishibashi·Rituparna Mandal·Nobuyoshi Ohta
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Abstract

We study anisotropic Bianchi-I cosmology, incorporating quantum gravitational corrections into the Einstein equation through the scale-dependent Newton coupling and cosmological term, as determined by the flow equation of the effective action for gravity. For the classical cosmological constant $\Lambda_0=0$, we derive the quantum mechanically corrected, or quantum-improved power-series solution for a general equation-of-state parameter $w$ in the range $-1 0$, we obtain the inverse power-series solution in the exponential of the cosmic time. We find that the universe always becomes isotropic in the late time, in accordance with the cosmic no hair theorem, and the quantum corrections make the isotropization faster. We also briefly summarize the Kasner solution and its generalization with quantum corrections.

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Chiang-Mei Chen, Akihiro Ishibashi, Rituparna Mandal, Nobuyoshi Ohta. 2025-09-11. Bianchi-I cosmology with scale dependent $G$ and $\Lambda$ in asymptotically safe gravity. https://arxiv.org/abs/2509.09759

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