  We show that the nonperturbative light-front dynamics of relativistic
hadronic bound states has a dual semiclassical gravity description on a higher
dimensional warped AdS space in the limit of zero quark masses. This mapping of
AdS gravity theory to the boundary quantum field theory, quantized at fixed
light-front time, allows one to establish a precise relation between
holographic wave functions in AdS space and the light-front wavefunctions
describing the internal structure of hadrons. The resulting AdS/QCD model gives
a remarkably good accounting of the spectrum, elastic and transition form
factors of the light-quark hadrons in terms of one parameter, the QCD gap
scale. The light-front holographic approach described here thus provides a
frame-independent first approximation to the light-front Hamiltonian problem
for QCD. This article is based on lectures at the Niccolo Cabeo International
School of Hadronic Physics, Ferrara, Italy, May 2011.
