Top-down holographic model for the composite Higgs scenario

We study the means to geometrically engineer a top-down holographic model for the composite Higgs scenario. Our construction modifies the Sakai-Sugimoto model for the holographic AdS/QCD, namely its variation based on the D4 brane stack wrapped over the orientifold with the orthogonal stack of D8 branes. The difficult question is how to geometrically engineer elementary fermion fields in the specific representations that allow the composite fermionic operators to emerge, which can be coupled appropriately to the Standard model fermions. We present the possible solutions to this problem and review the properties of the resulting composite Higgs models.