Lattice Quantum Gravity: EDT and CDT
arXiv:2209.06555
Abstract
This article is an overview of the use of so-called Euclidean Dynamical Triangulations (EDT) and Causal Dynamical Triangulations (CDT) as lattice regularizations of quantum gravity. The lattice regularizations have been very successful in the case of two-dimensional quantum gravity, where the lattice theories indeed provide regularizations of continuum well defined quantum gravity theories. In four-dimensional spacetime the Einstein-Hilbert action leads to a theory of gravity which is not renormalizable as a perturbative quantum theory around flat spacetime. It is discussed how lattice gravity in the form of EDT or CDT can be used to search for a non-perturbative UV fixed point of the lattice renormalization group in the spirit of asymptotic safety. In this way it might be possible to define a quantum theory of gravity also at lengthscales smaller than the Planck length.
arXiv commentContribution to the Handbook of Quantum Gravity, to appear in 2023. Some points clarified in the revised version