Critical distance and Crofton form in confining geometries

TL;DR

This paper investigates the critical distance for zero mutual information between symmetric strips in confining holographic geometries, revealing universal Crofton form behaviors and their relation to phase structures in holographic QCD models.

Contribution

It introduces a numerical method to determine the critical distance for mutual information drop and analyzes Crofton forms in various confining geometries, highlighting universal features.

Findings

Critical distance correlates with phase transitions in holographic models.

Crofton form exhibits universal behavior near IR cutoff points.

Scalar part of Crofton form becomes constant away from the IR wall.

Abstract

For two symmetric strips with equal and finite size and in the background of several confining geometries, we numerically calculate the critical distance between these two mixed systems where the mutual information between them drops to zero and show that this quantity could be a useful correlation measure in probing the phase structures of holographic QCD models. The models that we consider here are Sakai-Sugimoto and deformed Sakai-Sugimoto, Klebanov-Tseytlin and Maldacena Nunez. For evaluating the structures of these holographic supergravity geometries from the perspective of the bulk reconstruction, we also calculate their Crofton forms and show that there is a universal behavior in the confining backgrounds where a "well functionality" is present around the IR cutoff point, and far from the IR wall the scalar part of the Crofton form would become constant, demonstrating the effects of the wall of the confining models on the phase structures. This work is the shorter version of our previous work arXiv:2110.12970 with few more results about the connections between phases.