  Strongly interacting matter undergoes a crossover phase transition at high
temperatures $T\sim 10^{12}$ K and zero net-baryon density. A fundamental
question in the theory of strong interactions, Quantum Chromodynamics (QCD), is
whether a hot and dense system of quarks and gluons displays critical phenomena
when doped with more quarks than antiquarks, where net-baryon number
fluctuations diverge. Recent lattice QCD work indicates that such a critical
point can only occur in the baryon dense regime of the theory, which defies a
description from first principles calculations. Here we use the holographic
gauge/gravity correspondence to map the fluctuations of baryon charge in the
dense quark-gluon liquid onto a numerically tractable gravitational problem
involving the charge fluctuations of holographic black holes. This approach
quantitatively reproduces ab initio results for the lowest order moments of the
baryon fluctuations and makes predictions for the higher order baryon
susceptibilities and also for the location of the critical point, which is
found to be within the reach of heavy ion collision experiments.
