Putting a cap on causality violations in CDT

TL;DR

This paper explores a generalized 2D causal dynamical triangulations model that relaxes causality constraints with weighted branching points, providing an analytical solution in the genus-zero sector, advancing quantum gravity research.

Contribution

It introduces a novel generalization of 2D CDT with weighted branching points and solves it analytically in the genus-zero sector, extending the understanding of causality violations.

Findings

Analytical solution obtained for the generalized model

Demonstrated the impact of weighted branching points on causality

Extended the CDT framework to include partial causality violations

Abstract

The formalism of causal dynamical triangulations (CDT) provides us with a non-perturbatively defined model of quantum gravity, where the sum over histories includes only causal space-time histories. Path integrals of CDT and their continuum limits have been studied in two, three and four dimensions. Here we investigate a generalization of the two-dimensional CDT model, where the causality constraint is partially lifted by introducing weighted branching points, and demonstrate that the system can be solved analytically in the genus-zero sector.