2023/01/15 by J. Gizbert-Studnicki, Gizbert-Studnicki, Jakub · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Theory (hep-th) #Noncommutative and Quantum Gravity Theories
paper · pdf · doi:10.48550/arxiv.2301.06068
openalex publication_date 2023/01/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This article discusses the infrared and the (perspective) ultraviolet limits of four-dimensional Causal Dynamical Triangulations (CDT). CDT is a non-perturabtive and background-independent approach to quantization of Einstein's gravity, based on a lattice regularization of the quantum-gravitational path integral. It is shown that inside the, so-called, de Sitter phase one recovers a four-dimensional semiclassical universe, where behaviour of the scale factor is consistent with classical solutions of Einstein's field equations and fluctuations of the scale factor are very accurately described by a simple minisuperspace effective action. It is argued that some of the phase transitions bordering the semiclassical phase are higher-order transitions, which opens a possibility of defining a continuum limit of CDT. Finally, it is discussed how to define the renormalization group flow in CDT and then how to search for a UV fixed point in which, in the spirit of asymptotic safety, quantum theory of gravity could become non-perturbatively renormalizable and thus valid up to arbitrarily short distance scales.