Wormholes, a fluctuating cosmological constant and the Coleman mechanism

TL;DR

This paper demonstrates that in a 2D quantum gravity model, wormhole summation results in a Coleman mechanism where the cosmological constant effectively vanishes for large universes, with observable implications for topology fluctuations.

Contribution

It introduces a 2D quantum gravity model showing how wormhole summation leads to a fluctuating cosmological constant via a Coleman mechanism.

Findings

Wormhole configurations lead to a vanishing cosmological constant in large universes.

Observers perceive topology fluctuations as a fluctuating cosmological constant.

The model provides insight into the interplay between topology and cosmological constant in quantum gravity.

Abstract

We show that in a two-dimensional model of quantum gravity the summation over all possible wormhole configurations leads to a kind of Coleman mechanism where the cosmological constant plays no role for large universes. Observers who are unable to observe the change in topology will naturally interpret the measurements of the size of the universe as being caused by a fluctuating cosmological constant, rather than fluctuating topology of spacetime.