2,324 research outputs found
The three dimensional theory of gravitation based on a temporal scalar field in Riemanian geometry
A new approach to the model of the universe based on work by Rippl, Romero,
Tavakol is presented. We have used the scheme for relating the vacuum (D + 1)
dimensional theories to D dimensional theories for setting up a correspondence
between vacuum 4-dimensional Einstein theory with 3-dimensional gravity theory
with temporal scalar field. These ideas we continued by using the 3-dimensional
analog of Jordan, Brans-Dicke theory with temporal scalar field. As the result
space and time are treated in completely different ways. For the case of a
static spherically symmetric field new vacuum static solutions are found.Comment: 9 pages, Based on talks given at Santa Clara 2004. International
Workshop on Gravitation and Cosmology, Central University of Las Villas, 31
may-3 June, 2004, Cub
Static spherically symmetric constant density relativistic and Newtonian stars in the Lobachevskyan geometry
The present paper has the purpose to illustrate the importance of the ideas
and constructions of the Non-Euclidean (Lobachevsky) Geometry, which can be
applied even today for solving some conceptually important problems. We study
the static and spherically symmetric solutions to the Einstein field equations
under the assumption that the space-time may possess an arbitrary number of
spatial dimensions. A new exact solution of a perfect fluid sphere of constant
(homogeneous) energy-density which agrees with interior Lobachevsky geometry
for 3D and 4D spaces are found. We discuss the property of temporal scalar
field arise in lower-dimensional theories as the reduction of extra dimension.Comment: 10 page
On the Stability of Spherically Symmetric Configurations in Newtonian Limit of Jordan, Brans-Dicke Theory
We discuss stability of spherically symmetric static solutions in Newtonian
limit of Jordan, Brans-Dicke field equations. The behavior of the stable
equilibrium solutions for the spherically symmetric configurations considered
here, it emerges that the more compact a model is, the more stable it is.
Moreover, linear stability analysis shows the existence of stable
configurations for any polytropic index.Comment: 11 page
Composite spherically symmetric configurations in Jordan-Brans-Dicke theory
In this article, a study of the scalar field shells in relativistic
spherically symmetric configurations has been performed. We construct the
composite solution of Jordan-Brans-Dicke field equation by matching the
conformal Brans solutions at each junction surfaces. This approach allows us to
associate rigorously with all solutions as a single glued "space", which is a
unique differentiable manifold M^4.Comment: 6 page
Biology is a constructive physics
Yuri Manin's approach to Zipf's law (Kolmogorov complexity as energy) is
applied to investigation of biological evolution. Model of constructive
statistical mechanics where complexity is a contribution to energy is proposed
to model genomics. Scaling laws in genomics are discussed in relation to Zipf's
law. This gives a model of Eugene Koonin's Third Evolutionary Synthesis
(physical model which should describe scaling in genomics).Comment: 9 pages, commentaries adde
Dynamical systems where time is a quantum group and quantum ergodicity
We define dynamical systems where time is a quantum group. We give the
definition of quantum ergodicity for the introduced dynamical system with
noncommutative (or quantum) time, and discuss the examples.Comment: 4 pages, LaTe
Classification by Ensembles of Neural Networks
We introduce a new procedure for training of artificial neural networks by
using the approximation of an objective function by arithmetic mean of an
ensemble of selected randomly generated neural networks, and apply this
procedure to the classification (or pattern recognition) problem. This approach
differs from the standard one based on the optimization theory. In particular,
any neural network from the mentioned ensemble may not be an approximation of
the objective function.Comment: 8 pages, LaTe
The Heckmann's wormholes in Jordan-Brans-Dicke gravity
A simple Heckmann's vacuum wormhole solution of Jordan-Brans-Dicke
gravitation is presented and analysed. It is shown that in contrast with class
I Brans solution where the throat radius becomes real when here
it becomes positive when .Comment: 4 page
New static spheroidal solution in Jordan-Brands-Dicke theory
The static spheroidal solutions of Jordan-Brands-Dicke theory (JBD) are
studied. We consider the effect of the anisotropic stresses of scalar field on
the shape of JBD self-graviting objects. It is shown that scalar fields can
have significant effect on the structure and properties of self-graviting
objects. In contrast with general relativity in JBD theory there are nonflat
static spheroidal solutions.Comment: 5 page
The noncommutative replica procedure
The alternative to the replica procedure, which we call the noncommutative
replica procedure, is discussed. The detailed comparison with the standard
replica procedure is performed.Comment: 12 pages, LaTeX, Commentaries adde
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