"De Broglie-Bohm theory is a 'hidden variables' formulation of quantum
mechanics initially developed by de Broglie from 1923-1927 and clarified and
extended by Bohm beginning in 1952. In non-relativistic quantum theory it
differs from the orthodox viewpoint in that the notion of 'probability' refers to the
probability that a particle is at some position, rather than to its probability of
being found there in a suitable measurement. From this seemingly subtle
difference it is easy to show that - contrary to popular belief - QM can be
interpreted as a dynamical theory of particle trajectories rather than as a
statistical theory of observation. In such a formalism the standard paradoxes
related to measurement, observation and wave function collapse (Schroedinger's
cat, and so on) largely evaporate. The classical limit does not have to be
presupposed and emerges from the theory in a relatively clear way. All the 'talk'
is replaced by sharply-defined mathematics, it becomes possible to 'visualize' the
reality of most quantum events, and - most importantly - the theory is completely
consistent with the full range of QM predictive-observational data. While some
believe the study of interpretational questions to be mere semantics or 'just
philosophy', it is often forgotten that the location of the boundary between
philosophy and physics is unknown, and that one's philosophical perspective can
guide mathematical developments. For many people it is clear that de Broglie-
Bohm theory should be studied, not only because it is beginning to make
apparently testable predictions, but also because it has the potential to suggest
possible directions towards the next generation of ideas in theoretical physics.
Quantum non-equilibrium and 'signal non-locality'.
Dynamical relaxation to quantum equilibrium.
Potential instabilities in the Bohm dynamics.
Possible deeper interpretations of de Broglie-Bohm theory (such as Basil
Hiley's new quantum algebra work).
Pilot-wave field theories and relativistic generalizations
De Broglie-Bohm quantum cosmology
Deconstructing' the wave function. Can the theory be reduced to 3-space
waves? Norsen's 'theory of exclusively local beables'.
Proposed experimental tests (Valentini, Riggs, etc..)
The ontological status of the theory. First or Second order?
The arguments for and against psi-epistemic hidden-variables theories.
Alternative formulations of deterministic hidden-variables theories.
Non-Markovian trajectory theories.
Comparison with the consistent histories formulation
Use of trajectories for efficient numerical simulations in quantum chemistry.
Spin, antisymmetry, the exclusion principle and the 'quantum force.'
Responses to common objections (it's not possible for particles to exist; particles going round corners ought to radiate etc.)."
-- Michael Towler, Canbridge University, Web page