Gravity's Scalar Cousin

TL;DR

The paper proposes that the dilaton, the Goldstone boson of spontaneously broken conformal invariance, provides a scalar analog of gravity in flat spacetime. It develops a dilaton chiral Lagrangian with an auxiliary metric that yields emergent general covariance and an approximate Equivalence Principle, derives Newtonian gravity and Schwarzschild-radius scale behavior, and analyzes quantum EFT effects such as anomaly-mediated light bending. It further explores UV completions via conformal field theories, AdS/CFT duality, and higher-dimensional RS-like constructions that localize the dilaton, connecting holography and cosmology to scalar gravity. Overall, the work offers a tractable framework to probe gravity-like phenomena, cosmological constant issues, and UV completions in a scalar, conformal setting with potential insights for real gravity questions.

Abstract

The ``dilaton'', the Goldstone boson of spontaneously broken conformal field theories (in flat spacetime), is argued to provide a surprisingly provocative scalar analog of gravity. Many precise parallels and contrasts are drawn. In particular, the Equivalence Principle, the Cosmological Constant Problem, and the tension between them is shown to be closely replicated. Also, there is a striking transition when mass is compressed within the (analog) Schwarzchild radius. The scalar analogy may provide a simpler context in which to think about some of the puzzles posed by real gravity.