  A classical origin for the Bohmian quantum potential, as that potential term
arises in the quantum mechanical treatment of black holes and Einstein-Rosen
(ER) bridges, can be based on 4th-order extensions of Einstein's equations. The
required 4th-order extension of general relativity is given by adding quadratic
curvature terms with coefficients that maintain a fixed ratio, as their
magnitudes approach zero, with classical general relativity as a singular
limit. If entangled particles are connected by a Planck-width ER bridge, as
conjectured by Maldacena and Susskind, then a connection by a traversable
Planck-scale wormhole, allowed in 4th-order gravity, describes such
entanglement in the ontological interpretation. It is hypothesized that
higher-derivative gravity can account for the nonlocal part of the quantum
potential generally.
