Euclidean Wormholes and Gravitational States

TL;DR

This paper explores Euclidean wormholes as a means to generate semi-classical gravitational states, comparing them to Hartle-Hawking states, and discusses implications for the black hole information paradox and state overlaps.

Contribution

It introduces a new slicing method for Euclidean wormholes to produce semi-classical states and analyzes their overlaps with traditional states like the thermofield-double.

Findings

Semi-classical states can have order one overlap despite different Euclidean origins.

A microscopic CFT description of wormhole states is provided.

The factorization puzzle is reformulated in terms of entanglement and Hilbert space structure.

Abstract

Euclidean wormholes are known to encode important non-perturbative effects in the physics of quantum black holes. In this paper, we discuss the slicing of Euclidean wormholes along a time-reflection symmetric slice which treats half of the Euclidean geometry as a gravitational machinery to produce a semi-classical state. This type of state preparation is different from Hartle-Hawking states prepared with the CFT path integral, such as the thermofield-double state. Nevertheless, the two different types of states have order one overlaps provided the gravitational data agrees on the initial data slice. This raises an interesting puzzle: one can easily construct an infinite family of semi-classical states that have order one overlap with the thermofield double state, while having a very different Euclidean preparation. We provide a microscopic description of wormhole states in the dual CFT and reformulate the factorization puzzle in the language of entanglement and the Hilbert space.