1,832 research outputs found
Quantum Particles as Conceptual Entities: A Possible Explanatory Framework for Quantum Theory
We put forward a possible new interpretation and explanatory framework for
quantum theory. The basic hypothesis underlying this new framework is that
quantum particles are conceptual entities. More concretely, we propose that
quantum particles interact with ordinary matter, nuclei, atoms, molecules,
macroscopic material entities, measuring apparatuses, ..., in a similar way to
how human concepts interact with memory structures, human minds or artificial
memories. We analyze the most characteristic aspects of quantum theory, i.e.
entanglement and non-locality, interference and superposition, identity and
individuality in the light of this new interpretation, and we put forward a
specific explanation and understanding of these aspects. The basic hypothesis
of our framework gives rise in a natural way to a Heisenberg uncertainty
principle which introduces an understanding of the general situation of 'the
one and the many' in quantum physics. A specific view on macro and micro
different from the common one follows from the basic hypothesis and leads to an
analysis of Schrodinger's Cat paradox and the measurement problem different
from the existing ones. We reflect about the influence of this new quantum
interpretation and explanatory framework on the global nature and evolutionary
aspects of the world and human worldviews, and point out potential explanations
for specific situations, such as the generation problem in particle physics,
the confinement of quarks and the existence of dark matter.Comment: 45 pages, 10 figure
Cartoon Computation: Quantum-like computing without quantum mechanics
We present a computational framework based on geometric structures. No
quantum mechanics is involved, and yet the algorithms perform tasks analogous
to quantum computation. Tensor products and entangled states are not needed --
they are replaced by sets of basic shapes. To test the formalism we solve in
geometric terms the Deutsch-Jozsa problem, historically the first example that
demonstrated the potential power of quantum computation. Each step of the
algorithm has a clear geometric interpetation and allows for a cartoon
representation.Comment: version accepted in J. Phys.A (Letter to the Editor
Orthocomplementation and compound systems
In their 1936 founding paper on quantum logic, Birkhoff and von Neumann
postulated that the lattice describing the experimental propositions concerning
a quantum system is orthocomplemented. We prove that this postulate fails for
the lattice L_sep describing a compound system consisting of so called
separated quantum systems. By separated we mean two systems prepared in
different ``rooms'' of the lab, and before any interaction takes place. In that
case the state of the compound system is necessarily a product state. As a
consequence, Dirac's superposition principle fails, and therefore L_sep cannot
satisfy all Piron's axioms. In previous works, assuming that L_sep is
orthocomplemented, it was argued that L_sep is not orthomodular and fails to
have the covering property. Here we prove that L_sep cannot admit and
orthocomplementation. Moreover, we propose a natural model for L_sep which has
the covering property.Comment: Submitted for the proceedings of the 2004 IQSA's conference in
Denver. Revised versio
Quantum effects in linguistic endeavors
Classifying the information content of neural spike trains in a linguistic
endeavor, an uncertainty relation emerges between the bit size of a word and
its duration. This uncertainty is associated with the task of synchronizing the
spike trains of different duration representing different words. The
uncertainty involves peculiar quantum features, so that word comparison amounts
to measurement-based-quantum computation. Such a quantum behavior explains the
onset and decay of the memory window connecting successive pieces of a
linguistic text. The behavior here discussed is applicable to other reported
evidences of quantum effects in human linguistic processes, so far lacking a
plausible framework, since either no efforts to assign an appropriate quantum
constant had been associated or speculating on microscopic processes dependent
on Planck's constant resulted in unrealistic decoherence times
Classical Logical versus Quantum Conceptual Thought: Examples in Economics, Decision theory and Concept Theory
Inspired by a quantum mechanical formalism to model concepts and their
disjunctions and conjunctions, we put forward in this paper a specific
hypothesis. Namely that within human thought two superposed layers can be
distinguished: (i) a layer given form by an underlying classical deterministic
process, incorporating essentially logical thought and its indeterministic
version modeled by classical probability theory; (ii) a layer given form under
influence of the totality of the surrounding conceptual landscape, where the
different concepts figure as individual entities rather than (logical)
combinations of others, with measurable quantities such as 'typicality',
'membership', 'representativeness', 'similarity', 'applicability', 'preference'
or 'utility' carrying the influences. We call the process in this second layer
'quantum conceptual thought', which is indeterministic in essence, and contains
holistic aspects, but is equally well, although very differently, organized
than logical thought. A substantial part of the 'quantum conceptual thought
process' can be modeled by quantum mechanical probabilistic and mathematical
structures. We consider examples of three specific domains of research where
the effects of the presence of quantum conceptual thought and its deviations
from classical logical thought have been noticed and studied, i.e. economics,
decision theory, and concept theories and which provide experimental evidence
for our hypothesis.Comment: 14 page
Proper Versus Improper Mixtures: Towards a Quaternionic Quantum Mechanics
The density operators obtained by taking partial traces do not represent
proper mixtures of the subsystems of a compound physical system, but improper
mixtures, since the coefficients in the convex sums expressing them never bear
the ignorance interpretation. As a consequence, assigning states to these
subsystems is problematical in standard quantum mechanics (subentity problem).
Basing on the proposal provided in the SR interpretation of quantum mechanics,
where improper mixtures are considered as true nonpure states conceptually
distinct from proper mixtures, we show here that proper and improper mixtures
can be represented by different density operators in the quaternionic
formulation of quantum mechanics, hence they can be distinguished also from a
mathematical viewpoint. A simple example related to the quantum theory of
measurement is provided.Comment: 10 pages, standard latex, accepted for publication in Theoretical and
Mathematical Physic
CoRoT observations of O stars: diverse origins of variability
Six O-type stars were observed continuously by the CoRoT satellite during a
34.3-day run. The unprecedented quality of the data allows us to detect even
low-amplitude stellar pulsations in some of these stars (HD 46202 and the
binaries HD 46149 and Plaskett's star). These cover both opacity-driven modes
and solar-like stochastic oscillations, both of importance to the
asteroseismological modelling of O stars. Additional effects can be seen in the
CoRoT light curves, such as binarity and rotational modulation. Some of the
hottest O-type stars (HD 46223, HD 46150 and HD 46966) are dominated by the
presence of red-noise: we speculate that this is related to a sub-surface
convection zone.Comment: 5 pages, 3 figures, conference paper. To be published in "Four
decades of Research on Massive Stars", Astronomical Society of the Pacific.
Eds. C. Robert, N. St-Louis and L. Drisse
Studying the photometric and spectroscopic variability of the magnetic hot supergiant Orionis Aa
Massive stars play a significant role in the chemical and dynamical evolution
of galaxies. However, much of their variability, particularly during their
evolved supergiant stage, is poorly understood. To understand the variability
of evolved massive stars in more detail, we present a study of the O9.2Ib
supergiant Ori Aa, the only currently confirmed supergiant to host a
magnetic field. We have obtained two-color space-based BRIght Target Explorer
photometry (BRITE) for Ori Aa during two observing campaigns, as well
as simultaneous ground-based, high-resolution optical CHIRON spectroscopy. We
perform a detailed frequency analysis to detect and characterize the star's
periodic variability. We detect two significant, independent frequencies, their
higher harmonics, and combination frequencies: the stellar rotation period
d, most likely related to the presence of the
stable magnetic poles, and a variation with a period of d
attributed to circumstellar environment, also detected in the H and
several He I lines, yet absent in the purely photospheric lines. We confirm the
variability with /4, likely caused by surface
inhomogeneities, being the possible photospheric drivers of the discrete
absorption components. No stellar pulsations were detected in the data. The
level of circumstellar activity clearly differs between the two BRITE observing
campaigns. We demonstrate that Ori Aa is a highly variable star with
both periodic and non-periodic variations, as well as episodic events. The
rotation period we determined agrees well with the spectropolarimetric value
from the literature. The changing activity level observed with BRITE could
explain why the rotational modulation of the magnetic measurements was not
clearly detected at all epochs.Comment: 20 pages, 5 tables, 12 figures, accepted for publication in A&
Dihyperon in Chiral Colour Dielectric Model
The mass of dihyperon with spin, parity and isospin
is calculated in the framework of Chiral colour dielectric model. The wave
function of the dihyperon is expressed as a product of two colour-singlet
baryon clusters. Thus the quark wave functions within the cluster are
antisymmetric. Appropriate operators are then used to antisymmetrize
inter-cluster quark wave functions. The radial part of the quark wavefunctions
are obtained by solving the the quark and dielectric field equations of motion
obtained in the Colour dielectric model. The mass of the dihyperon is computed
by including the colour magnetic energy as well as the energy due to meson
interaction. The recoil correction to the dihyperon mass is incorporated by
Peierls-Yoccoz technique. We find that the mass of the dihyperon is smaller
than the threshold by over 100 MeV. The implications of our
results on the present day relativistic heavy ion experiments is discussed.Comment: LaTeX, 13 page
An investigation of CO2 splitting using nanosecond pulsed corona discharge: effect of argon addition on CO2 conversion and energy efficiency
The plasma chemical splitting of carbon dioxide (CO2) to produce carbon monoxide (CO) in a
pulsed corona discharge was investigated from both an experimental and a numerical standpoint.
High voltage nanosecond pulses were applied to a stream of pure CO2 and its mixture with argon,
and the gaseous products were identified using Fourier transform infrared spectroscopy. Due to the
shape of pulses, the process of CO2 splitting was found to proceed in two phases. The first phase is
dominated by ionization, which generates a high electron density. Then, during the second phase,
direct electron impact dissociation of CO2 contributes to a large portion of CO production.
Conversion and energy efficiency were calculated for the tested conditions. The conversions
achieved are comparable to those obtained using other high pressure non-thermal discharges, such as
dielectric barrier discharge. However, the energy efficiencies were considerably higher, which are
favorable to industrial applications that require atmospheric conditions and elevated gas flow rates
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