ISCOs in AdS/CFT

TL;DR

This paper analyzes stable circular orbits in AdS black holes across dimensions, providing analytic formulas for their properties and exploring their dual boundary interpretations involving non-perturbative effects and tunneling phenomena.

Contribution

It offers new analytic expressions for ISCOs in AdS black holes and connects bulk orbit properties with boundary tunneling and geodesic calculations.

Findings

Derived analytic formulas for ISCO size, angular velocity, and angular momentum.

Reproduced known binding energy and identified additional radial fluctuation energy.

Linked bulk particle orbits with boundary tunneling processes via geodesics and wave equations.

Abstract

We study stable circular orbits in spherically symmetric AdS black holes in various dimensions and their limiting innermost stable circular orbits (ISCOs). We provide analytic expressions for their size, angular velocity and angular momentum in a large black hole mass regime. The dual interpretation is in terms of meta-stable states not thermalising in typical thermal scales and whose existence is due to non-perturbative effects on the spatial curvature. Our calculations reproduce the binding energy known in the literature, but also include a binding energy in the radial fluctuations corresponding to near circular trajectories. We also describe how particles are placed on these orbits from integrated operators on the boundary: they tunnel inside in a way that can be computed from both complex geodesics in the black hole background and from the WKB approximation of the wave equation. We explain how these two computations are related.