Hybrid Fluid Models from Mutual Effective Metric Couplings

TL;DR

This paper develops a hybrid two-fluid model inspired by semi-holography, where two sectors interact via mutually determined effective metrics, and analyzes its equilibrium and hydrodynamic properties.

Contribution

It introduces a novel mutual effective metric coupling framework for two-fluid systems, extending semi-holographic modeling of quark-gluon plasma.

Findings

Derived the most general ultralocal interactions ensuring energy-momentum conservation.

Analyzed phase structure near thermal equilibrium.

Studied hydrodynamic modes and their stability.

Abstract

Motivated by a semi-holographic approach to the dynamics of quark-gluon plasma which combines holographic and perturbative descriptions of a strongly coupled infrared and a more weakly coupled ultraviolet sector, we construct a hybrid two-fluid model where interactions between its two sectors are encoded by their effective metric backgrounds, which are determined mutually by their energy-momentum tensors. We derive the most general consistent ultralocal interactions such that the full system has a total conserved energy-momentum tensor in flat Minkowski space and study its consequences in and near thermal equilibrium by working out its phase structure and its hydrodynamic modes.