Gauge fixing in Causal Dynamical Triangulations

TL;DR

This paper demonstrates that allowing a varying lapse in 1+1 dimensional causal dynamical triangulations does not affect physical observables, confirming that the time slicing is a gauge choice rather than a physical feature.

Contribution

It shows that the causal dynamical triangulation model's physical predictions are invariant under a varying lapse, supporting the gauge fixing interpretation of time slicing.

Findings

Physical observables remain unchanged with varying lapse.

Time slicing is a gauge choice, not a physical feature.

Supports gauge invariance in CDT models.

Abstract

We relax the definition of the Ambjorn-Loll causal dynamical triangulation model in 1+1 dimensions to allow for a varying lapse. We show that, as long as the spatially averaged lapse is constant in time, the physical observables are unchanged in the continuum limit. This supports the claim that the time slicing of the model is the result of a gauge fixing, rather than a physical preferred time slicing.