Sakharov's induced gravity: a modern perspective

TL;DR

This paper revisits Sakharov's 1967 concept of induced gravity, explaining how gravity can emerge from quantum field theory rather than being a fundamental force, and discusses modern interpretations of this idea.

Contribution

It provides a modern translation of Sakharov's original idea and surveys current versions of induced gravity theories.

Findings

Gravity can be viewed as an emergent phenomenon from quantum fields.

Modern formulations of Sakharov's idea are diverse and actively researched.

Induced gravity offers an alternative perspective to fundamental theories of gravity.

Abstract

Sakharov's 1967 notion of ``induced gravity'' is currently enjoying a significant resurgence. The basic idea, originally presented in a very brief 3-page paper with a total of 4 formulas, is that gravity is not ``fundamental'' in the sense of particle physics. Instead it was argued that gravity (general relativity) emerges from quantum field theory in roughly the same sense that hydrodynamics or continuum elasticity theory emerges from molecular physics. In this article I will translate the key ideas into modern language, and explain the various versions of Sakharov's idea currently on the market.