Wormholes in spacetimes with cosmological horizons

TL;DR

This paper extends the concept of quantum wormholes to spacetimes with cosmological horizons, specifically de Sitter space, and analyzes their properties and effects on low-energy physics.

Contribution

It proposes a generalized boundary condition for wormholes in spacetimes with horizons and explores the resulting quantum wave functions and their physical implications.

Findings

Wave functions are exponentially damped at large scales.

Wave functions include only outgoing modes beyond the horizon.

Effective interactions depend explicitly on the cosmological constant.

Abstract

A generalisation of the asymptotic wormhole boundary condition for the case of spacetimes with a cosmological horizon is proposed. In particular, we consider de Sitter spacetime with small cosmological constant. The wave functions selected by this proposal are exponentially damped in WKB approximation when the scale factor is large but still much smaller than the horizon size. In addition, they only include outgoing gravitational modes in the region beyond the horizon. We argue that these wave functions represent quantum wormholes and compute the local effective interactions induced by them in low-energy field theory. These effective interactions differ from those for flat spacetime in terms that explicitly depend on the cosmological constant.