  Holographic principles have impacted the way we look at strong coupling
phenomena in quantum chromodynamics, strongly interacting extensions of the
standard model, and {condensed-matter} physics. In real world settings,
however, we still lack understanding of why and when such an approach is
justified. Therefore, here, without invoking any such principle a priori, we
demonstrate how such a picture arises in the worldline formulation of quantum
field theory. Among other connections to holographic models, a warped AdS5
geometry, a quantum mechanical picture, and hidden local symmetry emerge, as
well as a Wilson flow (gradient flow), which extends the four-dimensional
sources to five-dimensional fields and a link to the Gutzwiller trace formula.
The worldline formulation also reproduces the non-relativistic case, which is
important for condensed-matter physics.
