Baryons in $SO(N)$ vector models and their duals in higher spin theory

Black shells, a kind of black hole mimickers, are identified thermodynamically as bulk duals of baryon operators in vector models, indicating that such objects are essential for the consistency of higher spin gravity theories. Thermal baryons, with a spectrum of a 2+1-dimensional relativistic Fermi gas, are found to be precursors of the deconfinement phase transition in vector models, condensing at a slightly lower temperature. The early condensation means that baryons are statistically important already in the phase with weakly interacting higher spin fields. Furthermore, the mysterious scale of the deconfinement transition in vector models is naturally interpreted as the Fermi energy scale in the gas.