190 research outputs found
Kinematic Quantities and Raychaudhuri Equations in a Universe
Based on some ideas emerged from the classical Kaluza-Klein theory, we
present a universe as a product bundle over the spacetime. This
enables us to introduce and study two categories of kinematic quantities
(expansions, shear, vorticity) in a universe. One category is related to
the fourth dimension (time), and the other one comes from the assumption of the
existence of the fifth dimension. The Raychaudhuri type equations that we
obtain in the paper, lead us to results on the evolution of both the
expansion and expansion in a universe.Comment: 27 page
Radially symmetric thin plate splines interpolating a circular contour map
Profiles of radially symmetric thin plate spline surfaces minimizing the
Beppo Levi energy over a compact annulus have been
studied by Rabut via reproducing kernel methods. Motivated by our recent
construction of Beppo Levi polyspline surfaces, we focus here on minimizing the
radial energy over the full semi-axis . Using a -spline
approach, we find two types of minimizing profiles: one is the limit of Rabut's
solution as and (identified as a
`non-singular' -spline), the other has a second-derivative singularity and
matches an extra data value at . For both profiles and , we establish the -approximation order in
the radial energy space. We also include numerical examples and obtain a novel
representation of the minimizers in terms of dilates of a basis function.Comment: new figures and sub-sections; new Proposition 1 replacing old
Corollary 1; shorter proof of Theorem 4; one new referenc
Transfinite thin plate spline interpolation
Duchon's method of thin plate splines defines a polyharmonic interpolant to
scattered data values as the minimizer of a certain integral functional. For
transfinite interpolation, i.e. interpolation of continuous data prescribed on
curves or hypersurfaces, Kounchev has developed the method of polysplines,
which are piecewise polyharmonic functions of fixed smoothness across the given
hypersurfaces and satisfy some boundary conditions. Recently, Bejancu has
introduced boundary conditions of Beppo Levi type to construct a semi-cardinal
model for polyspline interpolation to data on an infinite set of parallel
hyperplanes. The present paper proves that, for periodic data on a finite set
of parallel hyperplanes, the polyspline interpolant satisfying Beppo Levi
boundary conditions is in fact a thin plate spline, i.e. it minimizes a Duchon
type functional
A Finslerian version of 't Hooft Deterministic Quantum Models
Using the Finsler structure living in the phase space associated to the
tangent bundle of the configuration manifold, deterministic models at the
Planck scale are obtained. The Hamiltonian function are constructed directly
from the geometric data and some assumptions concerning time inversion
symmetry. The existence of a maximal acceleration and speed is proved for
Finslerian deterministic models. We investigate the spontaneous symmetry
breaking of the orthogonal symmetry SO(6N) of the Hamiltonian of a
deterministic system. This symmetry break implies the non-validity of the
argument used to obtain Bell's inequalities for spin states. It is introduced
and motivated in the context of Randers spaces an example of simple 't Hooft
model with interactions.Comment: 25 pages; no figures. String discussion deleted. Some minor change
Paraquaternionic CR-submanifolds of paraquaternionic Kahler manifolds and semi-Riemannian submersions
In this paper we introduce paraquaternionic CR-submanifolds of almost
paraquaternionic hermitian manifolds and state some basic results on their
differential geometry. We also study a class of semi-Riemannian submersions
from paraquaternionic CR-submanifolds of paraquaternionic Kaehler manifolds.Comment: 19 page
Ruled CR-submanifolds of locally conformal K\"{a}hler manifolds
The purpose of this paper is to study the canonical totally real foliations
of CR-submanifolds in a locally conformal K\"{a}hler manifold.Comment: 10 pages, Journal of Geometry and Physics (to appear
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