Quantum mechanics

Theoretical physics

Quantization (signal processing)

Variety (cybernetics)

Quantum gravity

Spin foam

Quantum process

Computer science

Loop quantum gravity

Classical mechanics

Physics

Quantum dynamics

Artificial intelligence

Quantum

Hořava–Lifshitz gravity

General relativity

Open quantum system

Computer vision

Classical and Quantum Gravity

Recent advances in cooling, control, and measurement of mechanical systems in the quantum regime have opened the possibility of the first direct observation of quantum gravity, at scales achievable in experiments. This paper gives a broad overview of this idea, using some matter-wave and optomechanical systems to illustrate the predictions of a variety of models of low-energy quantum gravity. We first review the treatment of perturbatively quantized general relativity as an effective quantum field theory, and consider the particular challenges of observing quantum effects in this framework. We then move on to a variety of alternative models, such as those in which gravity is classical, emergent, or responsible for a breakdown of quantum mechanics.

Tabletop experiments for quantum gravity: a user’s manual