8,665 research outputs found
Quantum Structures: An Attempt to Explain the Origin of their Appearance in Nature
We explain the quantum structure as due to the presence of two effects, (a) a
real change of state of the entity under influence of the measurement and, (b)
a lack of knowledge about a deeper deterministic reality of the measurement
process. We present a quantum machine, where we can illustrate in a simple way
how the quantum structure arises as a consequence of the two mentioned effects.
We introduce a parameter epsilon that measures the size of the lack of
knowledge on the measurement process, and by varying this parameter, we
describe a continuous evolution from a quantum structure (maximal lack of
knowledge) to a classical structure (zero lack of knowledge). We show that for
intermediate values of epsilon we find a new type of structure, that is neither
quantum nor classical. We apply the model that we have introduced to situations
of lack of knowledge about the measurement process appearing in other regions
of reality. More specifically we investigate the quantum-like structures that
appear in the situation of psychological decision processes, where the subject
is influenced during the testing, and forms some of his opinions during the
testing process. Our conclusion is that in the light of this explanation, the
quantum probabilities are epistemic and not ontological, which means that
quantum mechanics is compatible with a determinism of the whole.Comment: 22 pages, 8 figure
Bulk versus brane running couplings
A simplified higher dimensional Randall-Sundrum-like model in 6 dimensions is
considered. It has been observed previously by Goldberger and Wise that in such
a self-interacting scalar theory on the bulk with a conical singularity there
is mixing of renormalization of 4d brane couplings with that of the bulk
couplings. We study the influence of the running bulk couplings on the running
of the 4d brane couplings. We find that bulk quantum effects may completely
alter the running of brane couplings. In particular, the structure of the
Landau pole may be drastically altered and non-asymptotically free running may
turn into asymptotically safe (or free) behavior.Comment: 11 pages, no figures, REVTeX
Helical Packings and Phase Transformations of Soft Spheres in Cylinders
The phase behavior of helical packings of thermoresponsive microspheres
inside glass capillaries is studied as a function of volume fraction. Stable
packings with long-range orientational order appear to evolve abruptly to
disordered states as particle volume fraction is reduced, consistent with
recent hard sphere simulations. We quantify this transition using correlations
and susceptibilities of the orientational order parameter psi_6. The emergence
of coexisting metastable packings, as well as coexisting ordered and disordered
states, is also observed. These findings support the notion of phase
transition-like behavior in quasi-1D systems.Comment: 5 pages, with additional 4 pages of supplemental material, accepted
to Physical Review E: Rapid Communication
Entropy-Area Relations in Field Theory
We consider the contribution to the entropy from fields in the background of
a curved time-independent metric. To account for the curvature of space, we
postulate a position-dependent UV cutoff. We argue that a UV cutoff on energy
naturally implies an IR cutoff on distance. With this procedure, we calculate
the scalar contribution in a background anti-de Sitter space, the exterior of a
black hole, and de Sitter space. In all cases, we find results that can be
simply interpreted in terms of local energy and proper volume, yielding insight
into the apparent reduced dimensionality of systems with gravity.Comment: 20 pages, 1 figur
Conformal smectics and their many metrics
We establish that equally spaced smectic configurations enjoy an infinite-dimensional conformal symmetry and show that there is a natural map between them and null hypersurfaces in maximally symmetric spacetimes. By choosing the appropriate conformal factor it is possible to restore additional symmetries of focal structures only found before for smectics on flat substrates
Wave function of the radion in a brane world
We calculate the linearized metric perturbation corresponding to a massless
four-dimensional scalar field, the radion, in a five-dimensional two-brane
model of Randall and Sundrum. In this way we obtain relative strengths of the
radion couplings to matter residing on each of the branes. The results are in
agreement with the analysis of Garriga and Tanaka of gravitational and
Brans--Dicke forces between matter on the branes. We also introduce a model
with infinite fifth dimension and ``almost'' confined graviton, and calculate
the radion properties in that model.Comment: 5 pages revtex, no figures, equation correcte
Computer generated animation and movie production at LARC: A case study
The process of producing computer generated 16mm movies using the MOVIE.BYU software package developed by Brigham Young University and the currently available hardware technology at the Langley Research Center is described. A general overview relates the procedures to a specific application. Details are provided which describe the data used, preparation of a storyboard, key frame generation, the actual animation, title generation, filming, and processing/developing the final product. Problems encountered in each of these areas are identified. Both hardware and software problems are discussed along with proposed solutions and recommendations
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Results of an aqueous source term model for a radiological risk assessment of the Drigg LLW Site, U.K.
A radionuclide source term model has been developed which simulates the biogeochemical evolution of the Drigg low level waste (LLW) disposal site. The DRINK (DRIgg Near field Kinetic) model provides data regarding radionuclide concentrations in groundwater over a period of 100,000 years, which are used as input to assessment calculations for a groundwater pathway. The DRINK model also provides input to human intrusion and gaseous assessment calculations through simulation of the solid radionuclide inventory. These calculations are being used to support the Drigg post closure safety case. The DRINK model considers the coupled interaction of the effects of fluid flow, microbiology, corrosion, chemical reaction, sorption and radioactive decay. It represents the first direct use of a mechanistic reaction-transport model in risk assessment calculations
SMP: A solid modeling program version 2.0
The Solid Modeling Program (SMP) provides the capability to model complex solid objects through the composition of primitive geometric entities. In addition to the construction of solid models, SMP has extensive facilities for model editing, display, and analysis. The geometric model produced by the software system can be output in a format compatible with existing analysis programs such as PATRAN-G. The present version of the SMP software supports six primitives: boxes, cones, spheres, paraboloids, tori, and trusses. The details for creating each of the major primitive types is presented. The analysis capabilities of SMP, including interfaces to existing analysis programs, are discussed
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