Gauge theory origins of supergravity causal structure

TL;DR

The paper investigates how the causal structure of supergravity emerges from gauge theory duals in the AdS/CFT framework, focusing on both supergravity probes and D-brane probes. It shows that AdS5 causality maps to SYM kinematics via the UV/IR correspondence, while D-brane probes enforce causality dynamically through a Born-Infeld bound that becomes non-analytic when new light degrees of freedom, namely $W$-pairs, appear. At horizons, a single $W$ can become massless, and for non-extremal horizons this is tied to tachyonic instabilities; the authors support these claims with both Wilson-line worldsheet analyses and direct finite-temperature SYM calculations, linking horizon physics to the onset of light states in the gauge theory and to the stretched-horizon picture. The results provide a coherent gauge-theory mechanism for gravity causality and horizon physics, with implications for unitarity and the interpretation of horizons from outside and inside viewpoints.

Abstract

We discuss the gauge theory mechanisms which are responsible for the causal structure of the dual supergravity. For D-brane probes we show that the light cone structure and Killing horizons of supergravity emerge dynamically. They are associated with the appearance of new light degrees of freedom in the gauge theory, which we explicitly identify. This provides a picture of physics at the horizon of a black hole as seen by a D-brane probe.