A fundamental problem in quantizing general relativity

TL;DR

This paper identifies a fundamental incompatibility between the formulations of quantum mechanics and general relativity, highlighting the challenge of developing a quantum theory based on events rather than systems.

Contribution

It clarifies a core conceptual problem in quantizing gravity and proposes desiderata for a future event-based quantum theory, without providing a solution.

Findings

Highlights the mismatch between system-based quantum mechanics and event-based general relativity

Lays out key requirements for an event-based quantum theory of gravity

Identifies conceptual hurdles in unifying the two frameworks

Abstract

We point out a fundamental problem that hinders the quantization of general relativity: quantum mechanics is formulated in terms of systems, typically limited in space but infinitely extended in time, while general relativity is formulated in terms of events, limited both in space and in time. Many of the problems faced while connecting the two theories stem from the difficulty in shoe-horning one formulation into the other. A solution is not presented, but a list of desiderata for a quantum theory based on events is laid out.