De Sitter Universe from Causal Dynamical Triangulations without Preferred Foliation

TL;DR

This paper investigates a version of Causal Dynamical Triangulations (CDT) without a preferred foliation, demonstrating that a de Sitter universe emerges on large scales, suggesting the slicing is not essential for its quantum geometric properties.

Contribution

It introduces and analyzes a foliation-independent CDT model, showing that de Sitter spacetime arises without a distinguished time slicing.

Findings

Emergence of de Sitter universe in the model

Foliation independence does not hinder large-scale geometric properties

Numerical evidence supports the robustness of CDT results

Abstract

We present a detailed analysis of a recently introduced version of Causal Dynamical Triangulations (CDT) that does not rely on a distinguished time slicing. Focussing on the case of 2+1 spacetime dimensions, we analyze its geometric and causal properties, present details of the numerical set-up and explain how to extract "volume profiles". Extensive Monte Carlo measurements of the system show the emergence of a de Sitter universe on large scales from the underlying quantum ensemble, similar to what was observed previously in standard CDT quantum gravity. This provides evidence that the distinguished time slicing of the latter is not an essential part of its kinematical set-up.