scholarly journals ASTROPHYSICAL EVIDENCE FOR AN EXTRA DIMENSION: PHENOMENOLOGY OF A KALUZA–KLEIN THEORY

2013 ◽  
Vol 28 (18) ◽  
pp. 1330013
Author(s):  
D. PUGLIESE ◽  
G. MONTANI
Keyword(s):  
Three Dimensional ◽  
Geometric Theory ◽  
Relativistic Astrophysics ◽  
Dimensional Theory ◽  
Static Vacuum ◽  
Construction Of Self ◽  
Klein Theory ◽  
The Stability ◽  
Vacuum Solutions ◽  
Kaluza Klein

In this brief review, we discuss the viability of a multi-dimensional geometrical theory with one compactified dimension. We discuss the case of a Kaluza–Klein (KK) fifth-dimensional theory, addressing the problem by an overview of the astrophysical phenomenology associated with this five-dimensional (5D) theory. By comparing the predictions of our model with the features of the ordinary (four-dimensional (4D)) Relativistic Astrophysics, we highlight some small but finite discrepancies, expectably detectible from the observations. We consider a class of static, vacuum solutions of free electromagnetic KK equations with three-dimensional (3D) spherical symmetry. We explore the stability of the particle dynamics in these spacetimes, the construction of self-gravitating stellar models and the emission spectrum generated by a charged particle falling on this stellar object. The matter dynamics in these geometries has been treated by a multipole approach adapted to the geometric theory with a compactified dimension.

The importance of quantum effects in Kaluza–Klein theory

1986 ◽  
Vol 64 (5) ◽  
pp. 644-652 ◽  
Author(s):  
D. J. Toms
Keyword(s):  
Effective Action ◽  
Gauge Coupling ◽  
Quantum Effects ◽  
Induced Gravity ◽  
Yang Mills ◽  
Self Consistent ◽  
Klein Theory ◽  
Dimensional Gravity ◽  
The Stability ◽  
Kaluza Klein

This paper presents a discussion of the role of quantum effects in Kaluza–Klein theories. It is demonstrated why it is not possible to examine the existence of self-consistent solutions induced by quantum corrections to the classical theory if only the vacuum energy is used. The importance of the induced gravity and induced Yang–Mills terms in the effective action are emphasized. General criteria are given for the existence of self-consistent solutions in certain cases, and an expression is given for the gauge-coupling constant. Quantization of five-dimensional gravity with a cosmological constant is considered. Expressions are given for the constants that multiply the induced gravity and Yang–Mills terms in the one-loop effective action for this theory. Although the theory is one-loop finite, the necessity for performing finite renormalizations—a fact that has hitherto been overlooked—is discussed. Results of an analysis of the stability of self-consistent solutions are given, where it is shown why many of the solutions are unstable to small perturbations. A number of prospects for future work are given.

DIRAC FIELD IN THE FIVE-DEMENSIONAL KALUZA-KLEIN THEORY WITH SCALAR FIELD

1992 ◽  
Vol 07 (21) ◽  
pp. 5105-5113 ◽  
Author(s):  
A. MACÍAS ◽  
H. DEHNEN
Keyword(s):  
Scalar Field ◽  
Dirac Equation ◽  
Ground State ◽  
Mass Term ◽  
Dirac Field ◽  
Electron Mass ◽  
Dimensional Theory ◽  
Klein Theory ◽  
Kaluza Klein

In this work we investigate the five-dimensional Kaluza-Klein theory with a scalar field contained in the metric, where a Dirac-field is coupled to the metric field. We find that in the four-dimensional theory a nontrivial ground state for the scalar field exists and therefore the mass term in the Dirac equation can be interpreted, for example, as the electron mass.

Stability Loss in Thick Transversely Isotropic Cylindrical Shells Under Axial Compression

1993 ◽  
Vol 60 (2) ◽  
pp. 506-513 ◽  
Author(s):  
G. A. Kardomateas
Keyword(s):  
Axial Compression ◽  
Critical Loads ◽  
Shell Theory ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Stability Loss ◽  
Theory Of Elasticity ◽  
Dimensional Theory ◽  
Perfect Agreement ◽  
The Stability

The stability of equilibrium of a transversely isotropic thick cylindrical shell under axial compression is investigated. The problem is treated by making appropriate use of the three-dimensional theory of elasticity. The results are compared with the critical loads furnished by classical shell theories. For the isotropic material cases considered, the elasticity approach predicts a lower critical load than the shell theories, the percentage reduction being larger with increasing thickness. However, both the Flu¨gge and Danielson and Simmonds theories predict critical loads much closer to the elasticity value than the Donnell theory. Moreover, the values of n, m (number of circumferential waves and number of axial half-waves, respectively, at the critical point) for both the elasticity, and the Flu¨gge and the Danielson and Simmonds theories, show perfect agreement, unlike the Donnell shell theory.

Three-dimensional closed universes without collapse in a five-dimensional Kaluza-Klein theory

1985 ◽  
Vol 32 (12) ◽  
pp. 3114-3117 ◽  
Author(s):  
Richard A. Matzner ◽  
Anthony Mezzacappa
Keyword(s):  
Three Dimensional ◽  
Klein Theory ◽  
Kaluza Klein

DIRAC FIELD IN THE EIGHT-DIMENSIONAL KALUZA-KLEIN THEORY

1992 ◽  
Vol 07 (02) ◽  
pp. 103-116 ◽  
Author(s):  
A. MACIAS ◽  
H. DEHNEN
Keyword(s):  
Higgs Mechanism ◽  
Dirac Field ◽  
Dimensional Theory ◽  
Gauge Bosons ◽  
Mixing Angles ◽  
Curved Space ◽  
Left Handed ◽  
Group Manifold ◽  
Klein Theory ◽  
Kaluza Klein

We consider the eight-dimensional Kaluza-Klein theory where the extra dimensions are a SU(2)×U(1) group manifold. A Dirac-field is coupled to the metric field. As a result we obtain that the four-dimensional theory is non-chiral and contains no-kind of Higgs mechanism to predict gauge bosons, quark and lepton masses and mixing angles, although it exhibit to possess all gauge bosons and fermionic isospin couplings for left-handed particles of a Weinberg-Salam theory in a curved space-time.

BIANCHI IX GROUP-MANIFOLD REDUCTIONS OF GRAVITY

2005 ◽  
Vol 20 (40) ◽  
pp. 3115-3125
Author(s):  
ROMAN LINARES
Keyword(s):  
Lie Algebras ◽  
Three Dimensional ◽  
Einstein Gravity ◽  
Spin Connection ◽  
Higher Dimension ◽  
Dimensional Theory ◽  
Bianchi Ix ◽  
Group Manifold ◽  
Manifold Reduction ◽  
Kaluza Klein

We exhibit a new way to perform the group-manifold reduction of pure Einstein gravity in the vielbein formulation when the compactification group manifold is S3. The new Bianchi IX group-manifold reduction is obtained by exploiting the two three-dimensional Lie algebras that the S3 group manifold admits. As an application of the new reduction we show that there exists a domain wall solution to the lower-dimensional theory which upon uplifting to the higher-dimension turns out to be the self-dual (in the nonvanishing components of both curvature and spin connection) Kaluza–Klein monopole.

Supersymmetry: Kaluza-Klein theory, anomalies, and superstrings

1985 ◽  
Vol 146 (8) ◽  
pp. 655 ◽  
Author(s):  
I.Ya. Aref'eva ◽  
I.V. Volovich
Keyword(s):  
Klein Theory ◽  
Kaluza Klein

A Liquid Metal Flow Between Two Coaxial Cylinders System

2019 ◽  
Vol 11 (1) ◽  
pp. 79-86
Author(s):  
Abdelkrim Merah ◽  
Ridha Kelaiaia ◽  
Faiza Mokhtari
Keyword(s):  
Couette Flow ◽  
Metal Flow ◽  
Three Dimensional ◽  
Liquid Sodium ◽  
Taylor Vortex ◽  
Turbulent Regime ◽  
Coaxial Cylinders ◽  
Concentric Cylinders ◽  
Ideal Tool ◽  
The Stability

Abstract The Taylor-Couette flow between two rotating coaxial cylinders remains an ideal tool for understanding the mechanism of the transition from laminar to turbulent regime in rotating flow for the scientific community. We present for different Taylor numbers a set of three-dimensional numerical investigations of the stability and transition from Couette flow to Taylor vortex regime of a viscous incompressible fluid (liquid sodium) between two concentric cylinders with the inner one rotating and the outer one at rest. We seek the onset of the first instability and we compare the obtained results for different velocity rates. We calculate the corresponding Taylor number in order to show its effect on flow patterns and pressure field.

Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

Membrane theory

2017 ◽  
Author(s):  
David J. Steigmann
Keyword(s):  
Three Dimensional ◽  
Thin Sheets ◽  
Two Dimensional ◽  
Leading Order ◽  
Membrane Theory ◽  
Dimensional Theory ◽  
Small Thickness

This chapter develops two-dimensional membrane theory as a leading order small-thickness approximation to the three-dimensional theory for thin sheets. Applications to axisymmetric equilibria are developed in detail, and applied to describe the phenomenon of bulge propagation in cylinders.

Sign in / Sign up

Export Citation Format

Share Document