Holographic QCD matter in a bottom-up model

Fujii, Daisuke; Hosaka, Atsushi*; Iwanaka, Akihiro*; Sakai, Tadakatsu*; Tachibana, Motoi*

Understanding strongly coupled QCD matter remains challenging due to its non-perturbative nature. We study finite-density, zero-temperature QCD in a two-flavor hard-wall holographic model with nonzero quark mass. The dense phase is obtained by solving the classical equations of motion under a homogeneous ansatz. To relate bulk fields to boundary observables, we perform holographic renormalization and construct the dictionary, emphasizing the essential role of an IR boundary term at the hard-wall cutoff. Within this setup we uncover a baryonic phase with large baryon number density and a strongly suppressed chiral condensate. From these solutions we derive the equation of state and compute neutron-star mass-radius relations, finding stars above two solar masses over a broad parameter range.