Extended inflation in higher-dimensional spacetime with a Brans-Dicke scalar field

1993 ◽  
Vol 25 (3) ◽  
pp. 307-323 ◽  
Author(s):  
S. Chatterjee ◽  
A. Sil
Keyword(s):  
Scalar Field ◽  
Dimensional Spacetime ◽  
Higher Dimensional

scholarly journals COSMOLOGICAL CONSTANT, GENERATION OF DIMENSIONS AND THE EFFECTS OF ANISOTROPY IN MULTIDIMENSIONAL SPACETIME

2012 ◽  
Vol 27 (15) ◽  
pp. 1250088
Author(s):  
SERGEY V. YAKOVLEV
Keyword(s):  
Scalar Field ◽  
Cosmological Constant ◽  
Effective Mass ◽  
Vacuum Energy ◽  
Initial Conditions ◽  
Massless Scalar ◽  
Massless Scalar Field ◽  
Dimensional Spacetime ◽  
Higher Dimensional

In the paper, multidimensional anisotropic metric and density of vacuum energy in the Kasner's model are investigated. It is shown that the presence of scalar field in model is equivalent to metric in the spacetime with additional dimensions and we propose the idea of generating additional dimensions by massless scalar field. We propose a method of renormalization of metric that describes conversion from spacetime with scalar field to higher-dimensional spacetime. We obtain the expression for cosmological constant which depends on the initial conditions for anisotropic metric coefficients. Using the method of Bogolubov, we investigate the influence of anisotropic metric onto the cosmological birth of particles and obtain the effective mass of scalar field depending on the cosmological constant.

scholarly journals Quasinormal modes of massive scalar field with nonminimal coupling in higher-dimensional de Sitter black hole with single rotation

2019 ◽  
Vol 79 (12) ◽  
Author(s):  
Bogeun Gwak
Keyword(s):  
Black Hole ◽  
Scalar Field ◽  
Quasinormal Modes ◽  
Massive Scalar ◽  
Nonminimal Coupling ◽  
De Sitter ◽  
Massive Scalar Field ◽  
Outer Horizon ◽  
Dimensional Spacetime ◽  
Higher Dimensional

AbstractWe analytically investigate the quasinormal modes of the massive scalar field with a nonminimal coupling in the higher-dimensional de Sitter black hole with a single rotation. According to the separated scalar field equation, the boundary conditions of quasinormal modes are well constructed at the outer and cosmological horizons. Then, under near-extremal conditions, where the outer horizon closes to the cosmological horizon, the quasinormal frequencies are obtained and generalized to universal form in the higher-dimensional spacetime. Here, the real part of the frequency includes the scalar field contents, and its imaginary part only depends on the surface gravity at the outer horizon of the black hole.

NON-RIEMANNIAN GEOMETRIES AND HIGHER-DIMENSIONAL THEORIES OF SPACETIME

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1457-1464
Author(s):  
C. ROMERO
Keyword(s):  
Scalar Field ◽  
Vast Number ◽  
Cartan Geometry ◽  
Weyl Geometry ◽  
Torsion Field ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Classical Analogue ◽  
The One ◽  
Riemannian Geometries

We discuss the role that non-Riemannian geometries might play in the formulation of modern higher-dimensional spacetime theories. Among the vast number of non-Riemannian geometries we consider the two simplest ones: Weyl geometry and Riemann-Cartan geometry. We approach the problem of classical confinement of particles in branes and show how this question may be investigated in the context of the two mentioned geometries. We show that there is a classical analogue of the confinement of fermions induced by a scalar field and the one that might be induced by a Weyl field. In similar fashion we show that the same role may be played by a torsion field.

scholarly journals GRAVITY-WAVE DETECTORS AS PROBES OF EXTRA DIMENSIONS

2005 ◽  
Vol 14 (12) ◽  
pp. 2347-2353 ◽  
Author(s):  
CHRIS CLARKSON ◽  
ROY MAARTENS
Keyword(s):  
Black Holes ◽  
String Theory ◽  
Gravity Wave ◽  
Gravity Waves ◽  
Extra Dimensions ◽  
State Of The Art ◽  
Three Dimensional ◽  
Observable Universe ◽  
Dimensional Spacetime ◽  
Higher Dimensional

If string theory is correct, then our observable universe may be a three-dimensional "brane" embedded in a higher-dimensional spacetime. This theoretical scenario should be tested via the state-of-the-art in gravitational experiments — the current and upcoming gravity-wave detectors. Indeed, the existence of extra dimensions leads to oscillations that leave a spectroscopic signature in the gravity-wave signal from black holes. The detectors that have been designed to confirm Einstein's prediction of gravity waves, can in principle also provide tests and constraints on string theory.

FERMION PERTURBATIONS IN HIGHER-DIMENSIONAL STRING-THEORY BLACK HOLES

2013 ◽  
Vol 22 (10) ◽  
pp. 1350073
Author(s):  
OWEN PAVEL FERNÁNDEZ PIEDRA ◽  
JOSE BERNAL CASTILLO ◽  
YULIER JIMENEZ SANTANA ◽  
LEOSDAN FIGUEREDO NORIS
Keyword(s):  
Black Hole ◽  
Damping Factor ◽  
Test Field ◽  
Perfect Agreement ◽  
Massless Fermion ◽  
Time Domain Data ◽  
Fermion Fields ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
The Time Domain

In this paper, we report the results of a detailed investigation of the complete time evolution of massless fermion fields propagating in spacetimes of higher-dimensional stringy black hole solutions, obtained from intersecting branes in string/M theory. We write the Dirac equation in D-dimensional spacetime in a form suitable to perform a numerical integration of it, and using a Prony fitting of the time domain data, we determine the quasinormal frequencies that characterize the test field evolution at intermediary times. We also present the results obtained for the quasinormal frequencies using a sixth-order WKB approximation, that are in perfect agreement with the numerical results. The power-law exponents that describe the field relaxation at very late-times are also determined, and we show that they depends upon the dimensionality of spacetime, and are identical to that associated with the relaxation of boson fields for odd dimensions. The dependence of the frequencies and damping factor of the spinor field with the charges of the stringy black hole are studied.

scholarly journals ELEMENTARY PARTICLES AND SPIN REPRESENTATIONS

2004 ◽  
Vol 19 (05) ◽  
pp. 357-362 ◽  
Author(s):  
PAOLO MARANER
Keyword(s):  
Matter Field ◽  
Elementary Particles ◽  
Spacetime Symmetries ◽  
Spin Representation ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Spin Representations ◽  
Theoretical Considerations ◽  
Unified Description

We emphasize that the group-theoretical considerations leading to SO (10) unification of electroweak and strong matter field components naturally extend to spacetime components, providing a truly unified description of all generation degrees of freedoms in terms of a single chiral spin representation of one of the groups SO (13,1), SO (9,5), SO (7,7) or SO (3,11). The realization of these groups as higher-dimensional spacetime symmetries produces unification of all fundamental fermions is a single spacetime spinor.

scholarly journals MULTI-DIMENSIONAL COSMOLOGY AND DSR–GUP

2013 ◽  
Vol 28 (12) ◽  
pp. 1350047 ◽  
Author(s):  
K. ZEYNALI ◽  
F. DARABI ◽  
H. MOTAVALLI
Keyword(s):  
Cosmological Constant ◽  
Generalized Uncertainty Principle ◽  
Internal Space ◽  
Positive Cosmological Constant ◽  
Doubly Special Relativity ◽  
Dimensional Spacetime ◽  
Higher Dimensional ◽  
Big Crunch ◽  
The Difference ◽  
Cosmological Constants

A multi-dimensional cosmology with FRW type metric having four-dimensional spacetime and d-dimensional Ricci-flat internal space is considered with a higher-dimensional cosmological constant. The classical cosmology in commutative and Doubly Special Relativity–Generalized Uncertainty Principle (DSR–GUP) contexts is studied and the corresponding exact solutions for negative and positive cosmological constants are obtained. In the positive cosmological constant case, it is shown that unlike the commutative as well as GUP cases, in DSR–GUP case both scale factors of internal and external spaces after accelerating phase will inevitably experience decelerating phase leading simultaneously to a big crunch. This demarcation from GUP originates from the difference between the GUP and DSR–GUP algebras. The important result is that unlike GUP which results in eternal acceleration, DSR–GUP at first generates acceleration but prevents the eternal acceleration at late-times and turns it into deceleration.

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