Topology change in causal quantum gravity

TL;DR

This paper introduces a third quantization framework for two-dimensional quantum gravity using causal dynamical triangulation, emphasizing controlled topology change regulated by Newton's constant.

Contribution

It develops a novel third quantization approach for 2D quantum gravity with topology change, distinct from non-critical string theory, using CDT methods.

Findings

Topology change is well controlled by Newton's constant.

The construction is similar to, but physically distinct from, non-critical string field theory.

Provides a regulated framework for topology fluctuations in quantum gravity.

Abstract

The role of topology change in a fundamental theory of quantum gravity is still a matter of debate. However, when regarding string theory as two-dimensional quantum gravity, topological fluctuations are essential. Here we present a third quantization of two-dimensional surfaces based on the method of causal dynamical triangulation (CDT). Formally, our construction is similar to the c = 0 non-critical string field theory developed by Ishibashi, Kawai and others, but physically it is quite distinct. Unlike in non-critical string theory the topology change of spatial slices is well controlled and regulated by Newton's constant.