80 research outputs found
Isometry classification of cubic homogeneous 3-dimensional forms
The problem of classification of cubic homogeneous Finslerian 3D metrics with
respect to their isometries is considered. It is shown, that there are 6
different general affine types of such metrics. Algebras of isometries are
presented in apparent kind together with their affine-invariant properties.
Interrelation between symmetries and projective classifyings is discussed.Comment: Talk presented at the conference Symmetry-2009 (Hungary
Plate-Universe in Multidimensional Elasticity Theory
A number of boundary problems in multidimensional elasticity theory are
solved. The solutions can be treated as the simplest cosmological models. Some
specific properties of the solutions and experimental consequences of the
theory are discussed.Comment: 20 pages, 20 figure
Classical long-range interacting N-particle configurations and its applications
We consider classical N-particle system with arbitrary central pair
potential. Mechanical equilibrium condition in spherically-symmetric case leads
to a nonlinear integro-differential equation for concentration n(r). For
special state equation , original integro-differential
equation transforms into purely integral one. Its solution (under b=0) is
written through a row over interaction parameter. Physical conditions for its
convergency is discussed. For power-like potential kernal of integral operator
is calculated in apparent kind. The cases of Coulomb and harmonic potentials
are considered separately up to a third order. General scheme of application of
the theory for some astrophysical and cosmological problems is presented. Model
system with spherical potential pits is considered. By perturbation theory
first virial correction is calculated.Comment: Latex-2e, 14 pages, talk presented at school-seminar "Theoretical
problems of gravity and cosmology", Russia, Ulyanovsk, september 2000.
Shortened variant to be published in "Gravitation and Cosmology" 200
5-Dimensional Covariance and Generation of Solutions of Einstein Equations
A generation procedure, based on the 5-dimensional covariance of the
Kaluza-Klein theory, is developed. The procedure allows one to obtain exact
solutions of the 4-dimensional Einstein equations with electromagnetic and
scalar fields from vacuum 5-dimensional solutions using special 5-dimensional
coordinate transformations. Relations between the physical properties of the
resulting solutions and invariant geometrical properties of the generating
Killing vectors are found out.Comment: Latex 2.09, 6 page
Multidimensional generalization of Kasner solution
Full generalization of Kasner metric for the case of dimensions and
essential variables is obtained. Any solution is defined by the
corresponding constant matrix of Kasner parameters. This parameters form in
euclidian space Casner hyperspheres and are connected by additional conditions.
General properties of obtained solutions are analyzed.Comment: 9 pages, LaTe
Deformational Structures on Smooth Manifolds
Deformational structures, in many aspects generalizing standard elasticity
theory, are investigated in abstract form. Within free deformational structures
we define algebra of deformations, classify them by its special properties,
define motions and conformal motions together with deformational decomposition
of manifolds, generalizing isometry of Riemannian spaces and consider some
physical examples. In frame of dynamical deformational structures we formulate
variational procedure for evolutional and static cases together with boundary
conditions, derive dynamical (equilibrium in static case) equations, consider
perturbative approach and perform deformational realization of the well known
classical field-theoretical topics: strings and branes theories, classical
mechanics of solids, gravity and Maxwell electrodynamics.Comment: This is developed variant of talk, given at the 5-th ICGA conference
(Russia,Moscow, October 2001). To be published in Acta Phys. Polonica
2002-2003; Latex2e, 31 pages, 4 figure
Clasical solids dynamics as 4D statics of elastic strings
Variational principle for a solid in classical mechanics is formulated in
terms of a thin elastic 4D bar strain in Minkowsky events space of special
relativity. It is shown, that the sum of elastic 4-energies of weak twist and
bending under some identifications takes the form of classical non-relativistic
action for a solids dynamics. The necessary conditions on 4D bar parameters and
elastic constants, providing validity of Newton mechanics, are found.Comment: Latex 2e, 23 pages, 4 figures, talk at Ulyanovsk school-seminar 2000.
Accepted for printing in Nuovo Cimento
Space-time as multidimensional elastic plate
It is suggested, that a curved 4-dimensional space-time manifold is a
strained elastic plate in multidimensional embedding space-time. Its
thicknesses along extradimensions are much less than 4-dimensional sizes.
Reduced 4-dimensional free energy density of the strained plate in a weak
strain case is similar to GR Lagrangian density of a gravitational field for
the particular value of the Poisson coefficient of the plate. Dynamical
equations of the theory are obtained by variation of the multidimensional free
energy over displacement vector components. In general case they are
inhomogeneous bewave equations.Comment: 12 pages, 3 TexCad figures, Latex2
Are different geometries really that different?
Here is presented a concept of centrogeometry which can be seen as a
combination of the concept of point-like observer with an idea of
Poincar\'{e}'s that different geometries are principally equivalent. As it is
to be shown later, all centrogeometries are obtained from each other by general
deformation (i.e. active coordinate transformations). Isometries of
centrogeometries are equivalent to those of the Euclidean centrogeometry as
described by common diffeomorphisms of the Euclidean spheres. There are
discussed physical aspects of centrogeometry in the context of chronogeometry,
mechanics and cosmology.Comment: 13 pages, 2 figures, talk that will be presented at PIRT-2009, July
(Russia), one misprint is removed, formulation of the theorem is made more
clea
Geometrization of perfect fluid in 5-D Kaluza-Klein theory
General formulation of geometrization matter problem by scalar field with the help of possibilities of classical 5-D Kaluza-Klein
theory is given. Mathematical integrability conditions for such geometrization
for the case of perfect fluid are derived.Comment: Latex 2.09, 9 page
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