Spherically Collapsing Matter in AdS, Holography, and Shellons

TL;DR

This paper explores the holographic dual of a collapsing spherical shell in AdS space, revealing boundary signatures like shellons and linking bulk black hole formation to boundary thermalization.

Contribution

It introduces the concept of shellons as unstable boundary excitations and analyzes how bulk shell collapse affects boundary correlators and spacetime deformation.

Findings

Boundary correlators are modified by the shell's presence.

Shellons are unstable excitations with masses related to the shell radius.

Black hole formation correlates with boundary thermalization.

Abstract

We investigate the collapse of a spherical shell of matter in an anti-de Sitter space. We search for a holographic description of the collapsing shell in the boundary theory. It turns out that in the boundary theory it is possible to find information about the radial size of the shell. The shell deforms the background spacetime, and the deformed background metric enters into the action of a generic bulk field. As a consequence, the correlators of operators coupling to the bulk field are modified. By studying the analytic structure of the correlators, we find that in the boundary theory there are unstable excitations ("shellons") whose masses are multiples of a scale set by the radius of the shell. We also comment on the relation between black hole formation in the bulk and thermalization in the boundary.