4,376 research outputs found
Testing quantised inertia on galactic scales
Galaxies and galaxy clusters have rotational velocities apparently too fast
to allow them to be gravitationally bound by their visible matter. This has
been attributed to the presence of invisible (dark) matter, but so far this has
not been directly detected. Here, it is shown that a new model that modifies
inertial mass by assuming it is caused by Unruh radiation, which is subject to
a Hubble-scale (Theta) Casimir effect predicts the rotational velocity (v) to
be: v^4=2GMc^2/Theta (the Tully-Fisher relation) where G is the gravitational
constant, M is the baryonic mass and c is the speed of light. The model
predicts the outer rotational velocity of dwarf and disk galaxies, and galaxy
clusters, within error bars, without dark matter or adjustable parameters, and
makes a prediction that local accelerations should remain above 2c^2/Theta at a
galaxy's edge.Comment: 7 pages, 1 figure. Accepted for publication in Astrophysics and Space
Science on 27/7/201
Alien Registration- Mcculloch, Sadie B. (Eastport, Washington County)
https://digitalmaine.com/alien_docs/1398/thumbnail.jp
Correlation density matrices for 1- dimensional quantum chains based on the density matrix renormalization group
A useful concept for finding numerically the dominant correlations of a given
ground state in an interacting quantum lattice system in an unbiased way is the
correlation density matrix. For two disjoint, separated clusters, it is defined
to be the density matrix of their union minus the direct product of their
individual density matrices and contains all correlations between the two
clusters. We show how to extract from the correlation density matrix a general
overview of the correlations as well as detailed information on the operators
carrying long-range correlations and the spatial dependence of their
correlation functions. To determine the correlation density matrix, we
calculate the ground state for a class of spinless extended Hubbard models
using the density matrix renormalization group. This numerical method is based
on matrix product states for which the correlation density matrix can be
obtained straightforwardly. In an appendix, we give a detailed tutorial
introduction to our variational matrix product state approach for ground state
calculations for 1- dimensional quantum chain models. We show in detail how
matrix product states overcome the problem of large Hilbert space dimensions in
these models and describe all techniques which are needed for handling them in
practice.Comment: 50 pages, 34 figures, to be published in New Journal of Physic
Development and application of operational techniques for the inventory and monitoring of resources and uses for the Texas coastal zone
The author has identified the following significant results. Four LANDSAT scenes were analyzed for the Harbor Island area test sites to produce land cover and land use maps using both image interpretation and computer-assisted techniques. When evaluated against aerial photography, the mean accuracy for three scenes was 84% for the image interpretation product and 62% for the computer-assisted classification maps. Analysis of the fourth scene was not completed using the image interpretation technique, because of poor quality, false color composite, but was available from the computer technique. Preliminary results indicate that these LANDSAT products can be applied to a variety of planning and management activities in the Texas coastal zone
Ultraviolet detection from energetically deposited titania films
Thin films of unintentionally doped n-type titania have been energetically deposited from a filtered cathodic vacuum arc. All films were dense, smooth, and transparent with crystallinity depending on the deposition/annealing temperature. At a growth temperature of 600 C, the preferred phase could be changed from rutile to anatase by increasing the oxygen process pressure thereby reducing dynamic annealing. Pt/TiOx/Pt ultraviolet detectors exhibiting rectifying current-voltage characteristics and ultraviolet-visible rejection ratios exceeding 104 :1 were formed on selected films
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