  String theory's holographic QCD duality makes predictions for hadron physics
by building models that live in five-dimensional (5D) curved space. In this
pedagogical note, we explain how finding the hadron mass spectrum in these
models amounts to finding the eigenvalues of a time-independent,
one-dimensional Schroedinger equation. Changing the structure of the 5D curved
space is equivalent to altering the potential in the Schroedinger equation,
which in turn alters the hadron spectrum. We illustrate this concept with three
holographic QCD models possessing exact analogs in basic quantum mechanics: the
free particle, the infinite square well, and the harmonic oscillator. In
addition to making aspects of holographic QCD accessible to undergraduates,
this formulation can provide students with intuition for the meaning of curved
space. This paper is intended primarily as a tool for researchers interested in
involving early-stage undergraduates in research, but is also a suitable
introduction to elements of holographic QCD for advanced undergraduate- and
beginning graduate students with some knowledge of general relativity and
classical field theory.
