23,733 research outputs found
Navigation of Spacetime Ships in Unified Gravitational and Electromagnetic Waves
On the basis of a "local" principle of equivalence of general relativity, we
consider a navigation in a kind of "4D-ocean" involving measurements of
conformally invariant physical properties only. Then, applying the Pfaff theory
for PDE to a particular conformally equivariant system of differential
equations, we show the dependency of any kind of function describing "spacetime
waves", with respect to 20 parametrizing functions. These latter, appearing in
a linear differential Spencer sequence and determining gauge fields of
deformations relatively to "ship-metrics" or to "flat spacetime ocean metrics",
may be ascribed to unified electromagnetic and gravitational waves. The present
model is based neither on a classical gauge theory of gravitation or a
gravitation theory with torsion, nor on any Kaluza-Klein or Weyl type
unifications, but rather on a post-Newtonian approach of gravitation in a four
dimensional conformal Cosserat spacetime.Comment: 28 pages. Relative to the second version some changes in the
mathematical results have been corrected without consequences in the physical
model. The conformally flatness of the substratum spacetime which is an
assumption used throughout in the mathematical developements from chapter 2,
has been well precised in the first chapter. Clearer explanations at the very
end of chapter 3 about accelerating frames are given. New references are
indicated and some of them correcte
Separation of lymphocytes by electrophoresis under terrestrial conditions and at zero gravity
Electrophoretic mobility (EPM) of human peripheral lymphocytes were examined with the following objectives: To determine differences in EPM of lymphocytes under immuno-stimulated and immuno-suppressed states. To define the conditions necessary for the separation of lymphocyte sub-populations in normal and pathological conditions; To investigate immunological active, charged chemical groups on lymphocyte surfaces; and to investigate pathophysiological mechanisms of immune responsiveness, as reflected by alterations in EPM. To evaluate the potential of lymphocyte electrophoresis as: (1) a means of monitoring the immune status of kidney transplant recipients, (2) in predicting the outcome of kidney transplants, and (3) as a method for separation of lymphocyte sub-populations, the EPM was studied for unfractionated human peripheral lymphocytes and of populations enriched with T and "B" cells from normal adults, hemodialysis patients and kidney transplant recipients
Spacetime deployments parametrized by gravitational and electromagnetic fields
On the basis of a "Punctual" Equivalence Principle of the general relativity
context, we consider spacetimes with measurements of conformally invariant
physical properties. Then, applying the Pfaff theory for PDE to a particular
conformally equivariant system of differential equations, we make explicit the
dependence of any kind of function describing a "spacetime deployment", on
n(n+1) parametrizing functions, denoting by n the spacetime dimension. These
functions, appearing in a linear differential Spencer sequence and determining
gauge fields of spacetime deformations relatively to a "substrat spacetime",
can be consistently ascribed to unified electromagnetic and gravitational
fields, at any spacetime dimensions n greater or equal to 4.Comment: 26 pages, LaTeX2e, file macro "suppl.sty", correction in the
definition of germs and local ring
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