Baby universes in 2d quantum gravity

TL;DR

This paper explores the fractal geometry of two-dimensional quantum gravity, analyzing baby universes and their distributions across different models through numerical simulations to understand their structural properties.

Contribution

It introduces a detailed numerical analysis of baby universes in 2D quantum gravity, including models with matter fields, to measure their distribution and relate it to string susceptibility.

Findings

Measured baby universe distributions across models

Linked fractal structures to string susceptibility exponent

Provided numerical insights into quantum gravity surface roughness

Abstract

We investigate the fractal structure of $2d$ quantum gravity, both for pure gravity and for gravity coupled to multiple gaussian fields and for gravity coupled to Ising spins. The roughness of the surfaces is described in terms of baby universes and using numerical simulations we measure their distribution which is related to the string susceptibility exponent $\g_{string}$.