Friedmann-type cosmological solutions in Wesson's 5D space-time-mass theory of gravity

1990 ◽  
Vol 143 (4-5) ◽  
pp. 183-185 ◽  
Author(s):  
Guang-wen MA
Keyword(s):  
Space Time ◽  
Cosmological Solutions ◽  
Theory Of Gravity

scholarly journals Cosmic acceleration from varying masses in five dimensions

2016 ◽  
Vol 25 (01) ◽  
pp. 1650009 ◽  
Author(s):  
P. H. R. S. Moraes
Keyword(s):  
Space Time ◽  
Cosmic Acceleration ◽  
Expansion Velocity ◽  
Mass Variation ◽  
Five Dimensions ◽  
Matter Theory ◽  
Cosmological Solutions ◽  
Theory Of Gravity ◽  
The Universe ◽  
Made In

Much effort has been made in trying to solve or at least evade the inconsistencies that emerge from general relativity as the framework for a cosmological model. The extradimensional models rise as superb possibilities in this regard. In this work, I present cosmological solutions for Wesson’s space–time–matter theory of gravity. A relation between mass variation at cosmological scales and the expansion velocity of the universe is obtained. Such a relation yields novel features on space–time–matter theory of gravity, which are carefully discussed.

scholarly journals QUANTUM GEOMETRY AS A RELATIONAL CONSTRUCT

2002 ◽  
Vol 17 (09) ◽  
pp. 555-567 ◽  
Author(s):  
ALEJANDRO CORICHI ◽  
MICHAEL P. RYAN ◽  
DANIEL SUDARSKY
Keyword(s):  
Quantum Theory ◽  
Traditional Approach ◽  
Space Time ◽  
Quantum Geometry ◽  
Consistent Theory ◽  
Theory Of Gravity ◽  
Satisfactory Theory

The problem of constructing a quantum theory of gravity is considered from a novel viewpoint. It is argued that any consistent theory of gravity should incorporate a relational character between the matter constituents of the theory. In particular, the traditional approach of quantizing a space–time metric is criticized and two possible avenues for constructing a satisfactory theory are put forward.

THE DEVELOPMENT OF THE GRAVITATIONAL AND YANG–MILLS FIELDS, AND THE TREATMENT OF ACCELERATED FRAMES

2005 ◽  
Vol 20 (32) ◽  
pp. 7485-7504 ◽  
Author(s):  
JONG-PING HSU ◽  
DANA FINE
Keyword(s):  
Quantum Gravity ◽  
Flat Space ◽  
Physical World ◽  
Space Time ◽  
Yang Mills ◽  
Inertial Frames ◽  
Theory Of Gravity ◽  
Mills Field ◽  
Time Transformations ◽  
Accelerated Frames

We discuss ideas and problems regarding classical and quantum gravity, gauge theory of gravity, and space–time transformations between accelerated frames. Both Einstein's theory of gravity and Yang–Mills theory are gauge invariant. The invariance principles are at the very heart of our understanding of the physical world. This paper attempts to survey the development and to reveal problems and limitations of various formulations to gravitational and Yang–Mills fields, and to space–time transformations of accelerated frames. Gravitational force and accelerated frames are two ingredients in Einstein's thought in the period around 1907. Accelerated frames are difficult to define and are not well developed. However, one cannot claim to have a complete understanding of the physical world, if one understands flat space–time physics only from the viewpoint of the special class of inertial frames and ignores the vast class of noninertial frames. The paper highlights three aspects: (1) ideas of gravity as a Yang–Mills field, first discussed by Utiyama; (2) problems of quantum gravity, discussed by Feynman, Dyson and others; (3) space–time properties and the physics of fields and particles in accelerated frames of reference. These unfulfilled aspects of Einstein and Yang–Mills' profound thoughts present a challenge to physicists and mathematicians in the 21st century.

scholarly journals Nonlocal modified gravity and its cosmological solutions

2014 ◽  
Vol 12 (2) ◽  
pp. 139-150
Author(s):  
Branko Dragovich
Keyword(s):  
General Relativity ◽  
Analytic Function ◽  
Modified Gravity ◽  
Scale Factor ◽  
Complete Theory ◽  
Cosmic Scale ◽  
Nonlocal Models ◽  
Cosmological Solutions ◽  
Theory Of Gravity

Besides great achievements and many nice properties, general relativity as theory of gravity is not a complete theory. There are many attempts to its modification. One of promising modern approaches towards more complete theory of gravity is its nonlocal modification. We present here a brief review of nonlocal gravity with some its cosmological solutions. In particular, we pay special attention to two attractive nonlocal models, in which nonlocality is expressed by an analytic function of the d?Alembert operator ? = 1/?-g ???-gg????. In these models, we are mainly interested in nonsingular bounce solutions for the cosmic scale factor.

INFLATIONARY COSMOLOGICAL SOLUTIONS IN WEYL INTEGRABLE GEOMETRY

1998 ◽  
Vol 13 (12) ◽  
pp. 953-959 ◽  
Author(s):  
J. C. FABRIS ◽  
J. M. SALIM ◽  
S. L. SAUTU
Keyword(s):  
Cosmological Model ◽  
Singular Solution ◽  
Space Time ◽  
Inflationary Scenario ◽  
Cosmological Solutions ◽  
Isotropic Cosmological Model

We consider a homogeneous and isotropic cosmological model in Weyl integrable space–time. A general non-singular solution is obtained which is consistent with the inflationary scenario.

scholarly journals THE RELATION BETWEEN THE MODEL OF A CRYSTAL WITH DEFECTS AND PLEBANSKI'S THEORY OF GRAVITY

2013 ◽  
Vol 28 (13) ◽  
pp. 1350044 ◽  
Author(s):  
D. L. BENNETT ◽  
C. R. DAS ◽  
L. V. LAPERASHVILI ◽  
H. B. NIELSEN
Keyword(s):  
Geometric Property ◽  
Dynamical Variable ◽  
Space Time ◽  
Connection Formula ◽  
Crystalline Defects ◽  
The World ◽  
New Type ◽  
Topological Gravity ◽  
Theory Of Gravity ◽  
Nonzero Torsion

In the present investigation, we show that there exists a close analogy of geometry of space–time in general relativity (GR) with a structure of defects in a crystal. We present the relation between the Kleinert's model of a crystal with defects and Plebanski's theory of gravity. We have considered the translational defects — dislocations and the rotational defects — disclinations — in the three- and four-dimensional crystals. The four-dimensional crystalline defects present the Riemann–Cartan space–time which has an additional geometric property — "torsion" — connected with dislocations. The world crystal is a model for the gravitation which has a new type of gauge symmetry: the Einstein's gravitation has a zero torsion as a special gauge, while a zero connection is another equivalent gauge with nonzero torsion which corresponds to the Einstein's theory of "teleparallelism". Any intermediate choice of the gauge with nonzero connection [Formula: see text] is also allowed. In the present investigation, we show that in the Plebanski formulation the phase of gravity with torsion is equivalent to the ordinary or topological gravity, and we can exclude a torsion as a separate dynamical variable.

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