Aspects of Instanton Dynamics in AdS/CFT Duality

TL;DR

This paper explores instanton dynamics within the AdS/CFT duality framework for D0/D4 systems, analyzing instanton measures, stability, and condensates, revealing how these phenomena depend on size, compactification, and theta-angle effects.

Contribution

It provides a detailed holographic analysis of instanton measures, stability, and condensates in D0/D4 systems, connecting supergravity solutions with field theory instanton properties.

Findings

Derived the single-instanton measure in supergravity.

Showed instanton stability depends on size and theta-angle.

Established a holographic relation between theta angle and topological charge density.

Abstract

We consider aspects of instanton dynamics in the large-N limit using the AdS/CFT duality for D0/D4 bound states. In the supergravity picture of wrapped D0-brane world-lines on D4-branes, we find the single-instanton measure and discuss its dependence on compactification finite-size effects, as well as its matching to perturbative results. In the non-supersymmetric case, the same dynamical effects that produce the theta-angle dependence perturbatively in 1/N, render the instantons unstable, although approximate instantons of very small size still exist. The smeared D0/D4 black-brane supergravity solution can be interpreted as dual to a field theory configuration of an instanton condensate in the vacuum. In this case, we derive a holographic relation between the bare theta angle and the topological charge density of the instanton condensate.