316,308 research outputs found
Universal and homogeneous embeddings of dual polar spaces of rank 3 defined over quadratic alternative division algebras
Suppose O is an alternative division algebra that is quadratic over some subfield K of its center Z(O). Then with (O, K), there is associated a dual polar space. We provide an explicit representation of this dual polar space into a (6n + 7)-dimensional projective space over K, where n D dim(K)(O). We prove that this embedding is the universal one, provided vertical bar K vertical bar > 2. When O is not an inseparable field extension of K, we show that this universal embedding is the unique polarized one. When O is an inseparable field extension of K, then we determine the minimal full polarized embedding, and show that all homogeneous embeddings are either universal or minimal. We also provide explicit generators of the corresponding projective representations of the little projective group associated with the ( dual) polar space
Limitations on the smooth confinement of an unstretchable manifold
We prove that an m-dimensional unit ball D^m in the Euclidean space {\mathbb
R}^m cannot be isometrically embedded into a higher-dimensional Euclidean ball
B_r^d \subset {\mathbb R}^d of radius r < 1/2 unless one of two conditions is
met -- (1)The embedding manifold has dimension d >= 2m. (2) The embedding is
not smooth. The proof uses differential geometry to show that if d<2m and the
embedding is smooth and isometric, we can construct a line from the center of
D^m to the boundary that is geodesic in both D^m and in the embedding manifold
{\mathbb R}^d. Since such a line has length 1, the diameter of the embedding
ball must exceed 1.Comment: 20 Pages, 3 Figure
Fiber waveguide sensors for intelligent materials
This report, an addendum to the six month report submitted to NASA Langley Research Center in December 1987, covers research performed by the Fiber and Electro-Optics Research Center (FEORC) at Virginia Tech for the NASA Langley Research Center, Grant NAG1-780, for the period from December 1987 to June 1988. This final report discusses the research performed in the following four areas as described in the proposal: Fabrication of Sensor Fibers Optimized for Embedding in Advanced Composites; Fabrication of Sensor Fiber with In-Line Splices and Evaluation via OTR methods; Modal Domain Optical Fiber Sensor Analysis; and Acoustic Fiber Waveguide Implementation
The RARE model: a generalized approach to random relaxation processes in disordered systems
This paper introduces and analyses a general statistical model, termed the
RARE model, of random relaxation processes in disordered systems. The model
considers excitations, that are randomly scattered around a reaction center in
a general embedding space. The model's input quantities are the spatial
scattering statistics of the excitations around the reaction center, and the
chemical reaction rates between the excitations and the reaction center as a
function of their mutual distance. The framework of the RARE model is robust,
and a detailed stochastic analysis of the random relaxation processes is
established. Analytic results regarding the duration and the range of the
random relaxation processes, as well as the model's thermodynamic limit, are
obtained in closed form. In particular, the case of power-law inputs, which
turn out to yield stretched exponential relaxation patterns and asymptotically
Paretian relaxation ranges, is addressed in detail.Comment: 10 pages, REVTeX
The ideal center of the dual of a Banach lattice
Let be a Banach lattice. Its ideal center is embedded naturally in
the ideal center of its dual. The embedding may be extended to a
contractive algebra and lattice homomorphism of into . We show
that the extension is onto if and only if has a topologically full
center. (That is, for each , the closure of is the closed ideal
generated by .) The result can be generalized to the ideal center of the
order dual of an Archimedean Riesz space and in a modified form to the
orthomorphisms on the order dual of an Archimedean Riesz space
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