Classicalization and unitarization of wee partons in QCD and Gravity: The CGC-Black Hole correspondence

TL;DR

This paper explores a deep correspondence between black holes and color glass condensates, revealing shared features in their highly occupied states, entropy bounds, and classicalization processes in quantum gravity and QCD.

Contribution

It establishes a novel analogy between black hole graviton condensates and gluon states in QCD, linking their entropy and unitarization mechanisms through emergent semi-hard scales.

Findings

Black holes and CGCs share entropy bounds related to their constituent interactions.

Both systems exhibit classicalization of particle amplitudes at weak coupling.

Similarities in formation, thermalization, and decay processes between black holes and Glasma matter.

Abstract

We discuss a remarkable correspondence between the description of Black Holes as highly occupied condensates of $N$ weakly interacting gravitons and that of Color Glass Condensates (CGCs) as highly occupied gluon states. In both cases, the dynamics of "wee partons" in Regge asymptotics is controlled by emergent semi-hard scales that lead to perturbative unitarization and classicalization of $2\rightarrow N$ particle amplitudes at weak coupling. In particular, they attain a maximal entropy permitted by unitarity, bounded by the inverse coupling $\alpha$ of the respective constituents. Strikingly, this entropy is equal to the area measured in units of the Goldstone constant corresponding to the spontaneous breaking of Poincar{\'{e}} symmetry by the corresponding graviton or gluon condensate. In gravity, the Goldstone constant is the Planck scale, and gives rise to the Bekenstein-Hawking entropy. Likewise, in the CGC, the corresponding Goldstone scale is determined by the onset of gluon screening. We point to further similarities in Black Hole formation, thermalization and decay, to that of the Glasma matter formed from colliding CGCs in ultrarelativistic nuclear collisions, which decays into a Quark-Gluon Plasma.