de Sitter gravity from lattice gauge theory

TL;DR

This paper explores a lattice-based Euclidean quantum gravity model derived from the Palatini formulation, demonstrating that with suitable modifications, it can produce a ground state resembling Euclidean de Sitter space.

Contribution

It introduces a modified lattice gravity model that overcomes previous limitations, enabling the emergence of a de Sitter-like vacuum state.

Findings

Naive lattice approach fails to produce classical spacetime.

Adding a counter term allows for de Sitter ground states.

Monte Carlo simulations support the existence of de Sitter regions.

Abstract

We investigate a lattice model for Euclidean quantum gravity based on discretization of the Palatini formulation of General Relativity. Using Monte Carlo simulation we show that while a naive approach fails to lead to a vacuum state consistent with the emergence of classical spacetime, this problem may be evaded if the lattice action is supplemented by an appropriate counter term. In this new model we find regions of the parameter space which admit a ground state which can be interpreted as (Euclidean) de Sitter space.