8,357 research outputs found
Locus model for space-time fabric and quantum indeterminacies
A simple locus model for the space-time fabric is presented and is compared
with quantum foam and random walk models. The induced indeterminacies in
momentum are calculated and it is shown that these space-time fabric
indeterminacies are, in most cases, negligible compared with the quantum
mechanical indeterminacies. This result restricts the possibilities of an
experimental observation of the space-time fabric
Do we finally understand Quantum Mechanics?
The ontology emerging from quantum field theory and the results following
from Bell's theorems allowed the development of an intuitive picture of the
microscopic world described by quantum mechanics, that is, we can say that we
understand this theory. However there remain several aspects of it that are
still mysterious and require more work on the foundations of quantum mechanics.Comment: small corrections and improvements adde
Quantum stochastic processes in two dimensional space-time
Several stochastic processes with virtual particles in two dimensional
space-time are presented whose mean field equations coincide with
Schr\"odinger, Dirac, Klein-Gordon and the quantum mechanic equation for a
photon. These processes could be used to detect discrete space-time features at
the Planck scale.Comment: replacement including photon QM equatio
The position-momentum symmetry principle
It is shown that the Fourier transformation that relates position and
momentum representations of quantum mechanics can be understood as a
consequence of a symmetry principle that establishes the equivalence of being
and becoming in the description of reality. There are however other
transformation compatible with the same principle that could lead to different
formalisms of quantum mechanics
Relativity of representations in quantum mechanics
Only the position representation is used in introductory quantum mechanics
and the momentum representation is not usually presented until advanced
undergraduate courses. To emphasize the relativity of the representations of
the abstract formulation of quantum mechanics, two examples of representations
related to the operators aX+(1-a)P and (XP+PX)/2 are presented.Comment: 10 pages, no figures, accepted in Am.J.Phy
Understanding light quanta: The Photon
An antisymmetric tensor, the photon tensor, is defined for the description of
the photon as a massless relativistic particle. The photon can be visualized as
an essentially two dimensional rotating object. The quantum mechanical
description of a single photon is presented and it is shown that it is wrong to
associate the quantum states of a photon with the macroscopic electromagnetic
fields. This work is part of a series devoted to the attempt to understand the
quantum of electromagnetic radiation, based on the assumption that the photons
are the primary ontology and that the electromagnetic fields are macroscopic
emergent properties of an ensemble of photons.Comment: minor corrections, references adde
Understanding light quanta:Construction of the free electromagnetic field
The free electromagnetic field, solution of Maxwell's equations and carrier
of energy, momentum and spin, is construed as an emergent collective property
of an ensemble of photons, and with this, the consistency of an interpretation
that considers that the photons, and not the electromagnetic fields, are the
primary ontology is established.Comment: Continuation of quant-ph/0410171 and quant-ph/0410179 Comment added
and references update
A quantum arrow of time
It is shown that position-momentum correlation is never decreasing and
therefore it is a good candidate as a quantum arrow of time devoid of
shortcomings of other proposals
The quantum field theory interpretation of quantum mechanics
It is shown that adopting the \emph{Quantum Field} ---extended entity in
space-time build by dynamic appearance propagation and annihilation of virtual
particles--- as the primary ontology the astonishing features of quantum
mechanics can be rendered intuitive. This interpretation of quantum mechanics
follows from the formalism of the most successful theory in physics: quantum
field theory
Quantum state reconstruction from dynamical systems theory
When an informationally incomplete set of observables is considered there are
several solutions to the quantum state reconstruction problem using von Neumann
measurements. The set of solutions are known as Pauli partners, which are not
easy to find even numerically. We present, in a self-contained paper, a new way
to find this solutions using the physical imposition operator. We show that
every Pauli partner is an attractive fixed point of this operator, which means
that we can find complete sets of Pauli partners very efficiently. As a
particular case, we found numerically 24 mutually unbiased bases in dimension
N=23 in less than 30 seconds in a standard PC. We hope that the algorithm
presented can be adapted to construct MU Constellations, SIC-POVMs, Equiangular
Tight Frames and Quantum t-Designs, which could open new possibilities to find
numerical solutions to these open problems related with quantum information
theory.Comment: A completely new paper has been written with the same aim of this
work. See D. Goyeneche, A.C. de la Torre "Quantum tomography meets dynamical
systems and bifurcations theory
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