In this review, we provide an up-to-date account of quantitative bottom-up holographic descriptions of the strongly coupled quark–gluon plasma (QGP) produced in relativistic heavy-ion collisions, based on the class of gauge-gravity Einstein–Maxwell–Dilaton (EMD) effective models. The holographic approach is employed to tentatively map the QCD phase diagram at finite temperature onto a dual theory of charged, asymptotically Anti-de Sitter (AdS) black holes living in five dimensions. With a quantitative focus on the hot QCD phase diagram, the nonconformal holographic EMD models reviewed here are adjusted to describe first-principles lattice results for the finite-temperature QCD equation of state, with $2+1$ flavors and physical quark masses, at zero chemical potential and vanishing electromagnetic fields. We review the evolution of such effective models and the corresponding improvements produced in quantitative holographic descriptions of the deconfined hot QGP phase of QCD. The predictive power of holographic EMD models is tested by quantitatively comparing their predictions for the hot QCD equation of state at nonzero baryon density and the corresponding state-of-the-art lattice QCD results. Hydrodynamic transport coefficients such as the shear and bulk viscosities predicted by these EMD constructions are also compared to the corresponding profiles favored by the latest phenomenological multistage models simultaneously describing different types of heavy-ion data. We briefly report preliminary results from a Bayesian analysis using EMD models, which provide systematic evidence that lattice QCD results at finite temperature and zero baryon density strongly constrains the free parameters of such bottom-up holographic constructions. Remarkably, the set of parameters constrained by lattice results at vanishing chemical potential turns out to produce EMD models in quantitative agreement with lattice QCD results also at finite baryon density. We also review results for equilibrium and transport properties from magnetic EMD models, which effectively describe the hot and magnetized QGP at finite temperatures and magnetic fields with zero chemical potentials. Finally, we provide a critical assessment of the main limitations and drawbacks of the holographic models reviewed in the present work, and point out some perspectives we believe are of fundamental importance for future developments.

在这篇综述中，我们基于规范重力爱因斯坦-麦克斯韦类，提供了对相对论性重离子碰撞中产生的强耦合夸克-胶子等离子体（QGP）的定量自下而上全息描述的最新描述–膨胀（EMD）有效模型。采用全息方法将有限温度下的 QCD 相图暂时映射到五维带电渐近反德西特 (AdS) 黑洞的对偶理论上。通过定量关注热 QCD 相图，调整此处回顾的非共形全息 EMD 模型来描述有限温度 QCD 状态方程的第一性原理晶格结果，其中$2+1$味道和物理夸克质量，化学势为零，电磁场消失。我们回顾了此类有效模型的演变以及 QCD 去约束热 QGP 相的定量全息描述中产生的相应改进。通过定量比较全息 EMD 模型对非零重子密度下热 QCD 状态方程的预测和相应的最先进晶格 QCD 结果，测试了全息 EMD 模型的预测能力。这些 EMD 结构预测的流体动力输运系数（例如剪切粘度和体积粘度）也与同时描述不同类型重离子数据的最新唯象多级模型所支持的相应曲线进行了比较。我们简要报告了使用 EMD 模型进行贝叶斯分析的初步结果，该结果提供了系统证据，表明有限温度和零重子密度下的晶格 QCD 结果强烈限制了这种自下而上的全息结构的自由参数。值得注意的是，在化学势消失时，受晶格结果约束的参数集最终产生了与有限重子密度下的晶格 QCD 结果定量一致的 EMD 模型。我们还回顾了磁性 EMD 模型的平衡和输运特性结果，该模型有效地描述了有限温度和零化学势磁场下的热和磁化 QGP。最后，我们对当前工作中审查的全息模型的主要局限性和缺点进行了批判性评估，并指出了我们认为对未来发展至关重要的一些观点。