The non-relativistic quantum theory has been interpreted causally by de Broglie, David Bohm, and others, where a quantum entity is viewed as a particle with a definite position and momentum. This interpretation contrasts with the Copenhagen orthodox interpretation, which conveys uncertainty through the commutator relationship between position and momentum operators. This is further exacerbated by the de Broglie-Bohm interpretation, which uses no operators corresponding to these observables. We reconcile these opposing viewpoints by introducing mathematical nonlinear transforms in Bohmian mechanics for the momentum observable. While these nonlinear operator-like transforms cannot be easily represented as matrices in the Hilbert space, we show that they can be utilized in the de Broglie-Bohm interpretations of quantum theory.
The de Broglie-Bohm interpretation is known to make the vagueness of the Copenhagen interpretation precise. What this actually means is that it offers a purely materialist framework for understanding quantum mechanics, as opposed to a dualist or idealist framework. The Copenhagen interpretation introduces conscious observers into its ontology and therefore lacks the precision of a materialist scientific theory expressible in terms of mathematics. The corollary of this is that using the de Broglie-Bohm interpretation as a proof by contradiction, it can be shown that if consciousness is not epiphenomenal but instead has causal efficacy, then the Born rule probabilities must be incomplete, and both the de Broglie-Bohm and Copenhagen interpretations are incomplete.
We introduce the de Broglie-Bohm causal interpreation of quantum mechanics and compare it to the standard interpretation of quantum mechanics, the Copenhagen interpretation. We examine the possibility of experimentally distinguishing between the two theories, as well as the potential for the causal interpretation to more easily bridge the gap between the physics of the quantum and classical worlds. We then use the causal interpretation to construct a deterministic model of the helium atom in which the two electrons move along trajectories through space and time about a stationary nucleus. The dynamics are governed by the non-relativistic Schrödinger equation and the spin vectors of both electrons are assumed to be constant along their respective trajectories. We examine the Bohmian trajectories associated with (approximations to) eigenstates of the helium Hamiltonian as well as the trajectories associated with some non-eigenstates. We also compute an approximation to the ground state energy of the helium atom using a representation of the helium wavefunction in terms of hydrogenic eigenfunctions which is motivated by a perturbation approach.
In this paper the quantised version of Newton Second Law is derived assuming merely the existence of de Broglie matter-waves and their basic properties. At the same time we keep an eye towards interpretations of quantum mechanics and will realise that the two most different interpretations (Copenhagen interpretation and the de Broglie-Bohm theory) owe their difference to two fundamentally different approaches to `Harmonisation'. In this regard we shall see that the guiding equation of the de Broglie-Bohm theory currently found in literature is not the most complete equation possible; as a result we answer one of the important questions in interpreting quantum mechanics, namely that `when does the concept of classical path (trajectory) makes sense in quantum mechanics?' Moreover, in light of special-relativistic considerations we shall easily see that in the Number-Division approach, i.e. that of de Broglie-Bohm, the wave operator no longer appears, making it in turn impossible the application of Clifford algebras (Dirac's `square root' of the wave operator).
The de Broglie–Bohm interpretation (Bohmian mechanics, hidden-variables theory, causal interpretation
or pilot-wave theory) is one of the interpretations of quantum mechanics which opposes
to the claim of standard interpretation on the completeness of description of the state of quantummechanical
system, that description in Bohmian mechanics is completed by defining positions of
the particles of the system i.e. hidden variables and their dynamics. These facts are the basis of motivation
for the introduction of a new theory that can describe dubious axiomatic requirements of
standard interpretation. The presented theory is deterministic and explicitly nonlocal. Originators
of Bohmian mechanics were L. de Broglie (1927.) and D. Bohm (1952.) who presented mathematically
more general and conceptual elaborate formulation. Along with the historical overview,
a note is given about the main properties of the theory, such as the issue of nonlocality and hidden
variables. The aim of this paper is to present and explain the main ideas and properties of the
theory as well as to give a systematic overview of present and historical mathematical construction
of the theory and most of all to discuss implications of de Broglie–Bohm theory on the ontology of
quantum-mechanical picture, showcasing examples of the equivalency of the description of a free
particle as a propagation of the plane wave in space or as the ensemble of the trajectories and of
the spreading of the Gaussian wave packet. The main example of the obvious conceptual clashing
of the interpretations is presented: the double-slit experiment, with a detailed examination of the
Bohmian mechanics’ predictions using presented formalism on the two double-slit experiment.
The graphs of trajectories for given examples are obtained.
de Broglie-Bohm theory (dBBT), treating quantum particles as point objects moving along well defined (Bohmian) trajectories, offers an appealing solution of the measurement problem in quantum mechanics; it has, however, problems relating to spin, relativity and lack of proper integration with the Hilbert space based framework. In this work, we present a consistent formalism which has the traditional state-observable framework integrated with the desirable features of dBBT. We adopt ensemble interpretation for the Schrodinger wave function
ψ. Given a Schrodinger wave function
ψ, we use its value
ψ0 at some fixed time (say,
t=0) to define the probability measure
∣ψ0∣2dx on the system configuration space
M (
=Rn). On the resulting probability space
M0, we introduce a stochastic process
ξ(t) corresponding to the Heisenberg position operator
XH(t) such that, in the Heisenberg state
∣ψh⟩ corresponding to
ψ0, the expectation value of
XH(t) equals that of
ξ(t) in
M0. This condition leads to the de Broglie-Bohm guidance equation for the sample paths of the process
ξ(t) which are, therefore, Bohmian trajectories supposedly representing time-evolutions of individual members of the
ψ0-ensemble. Stochastic processes and Bohmian trajectories corresponding to observables with discrete eigenvalues (in particular spin) are treated by extending the configuration space to the spectral space of the commutative algebra obtained by adding appropriate discrete observables to the position observables. Pauli's equation is treated as an example. A straightforward derivation of von Neumann's projection rule employing the Schrodinger-Bohm evolution of individual systems along their Bohmian trajectories is given. Some comments on the potential application of the formalism developed here to quantum mechanics of the universe are included.
The Copenhagen interpretation has been the subject of much criticism, notably by De Broglie and Einstein, because it contradicts the principles of causality and realism. The aim of this essay is to study the wave mechanics as an alternative to traditional quantum mechanics, in the continuity of the ideas of Louis de Broglie: the pilot wave theory of De Broglie (where each particle is associated with a wave which guides it), De Broglie-Bohm theory, stochastic electrodynamics (where the stochastic character of particles is caused by the energy field of the fluctuating vacuum), and the analogies between quantum mechanics and hydrodynamics.