scholarly journals Inflationary limits on the size of compact extra space

2019 ◽  
Vol 28 (13) ◽  
pp. 1941004 ◽  
Author(s):  
V. V. Nikulin ◽  
Sergey G. Rubin
Keyword(s):  
Scalar Field ◽  
Planck Mass ◽  
Extra Space ◽  
Inflationary Models ◽  
Kaluza Klein

We study restrictions imposed on the parameters of the Kaluza–Klein extra space supplied by the standard inflationary models. It is shown that the size of the extra space cannot be larger than [Formula: see text][Formula: see text]cm and the [Formula: see text]-dimensional Planck mass should be larger than [Formula: see text][Formula: see text]GeV. The validity of these estimates is discussed. We also study creation of stable excitations of scalar field as the result of the extra metric evolution.

KALUZA–KLEIN BOTTLE COUPLED TO TOLMAN–HAWKING WORMHOLE

1991 ◽  
Vol 06 (17) ◽  
pp. 1547-1552
Author(s):  
A. DAVIDSON ◽  
Y. VERBIN
Keyword(s):  
Scalar Field ◽  
Klein Bottle ◽  
Gauge Coupling ◽  
Coupling Constants ◽  
Five Dimensions ◽  
Symmetric Configuration ◽  
Kaluza Klein

Asymptotically Euclidean regions connected by a wormhole may differ by their associated gauge coupling constants. This idea is realized in a field-theoretical manner using a conformally coupled scalar field in five dimensions. An SO (4) × U (1) e.m. -symmetric configuration is derived, describing a Kaluza–Klein bottle coupled to a Tolman–Hawking wormhole.

scholarly journals Fermion localization in braneworld teleparallel f(T, B) gravity

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
A. R. P. Moreira ◽  
J. E. G. Silva ◽  
C. A. S. Almeida
Keyword(s):  
Scalar Field ◽  
Yukawa Coupling ◽  
Spinor Field ◽  
Quantum Potential ◽  
Boundary Term ◽  
Dirac Spinor ◽  
Kaluza Klein ◽  
Fermion Localization

AbstractWe study a spin 1/2 fermion in a thick braneworld in the context of teleparallel f(T, B) gravity. Here, f(T, B) is such that $$f_1(T,B)=T+k_1B^{n_1}$$ f 1 ( T , B ) = T + k 1 B n 1 and $$f_2(T,B)=B+k_2T^{n_2}$$ f 2 ( T , B ) = B + k 2 T n 2 , where $$n_{1,2}$$ n 1 , 2 and $$k_{1,2}$$ k 1 , 2 are parameters that control the influence of torsion and the boundary term. We assume Yukawa coupling, where one scalar field is coupled to a Dirac spinor field. We show how the $$n_{1,2}$$ n 1 , 2 and $$k_{1,2}$$ k 1 , 2 parameters control the width of the massless Kaluza–Klein mode, the breadth of non-normalized massive fermionic modes and the properties of the analogue quantum-potential near the origin.

scholarly journals SPECTRA OF RELIC GRAVITONS AND BRANS–DICKE THEORY

2005 ◽  
Vol 20 (02) ◽  
pp. 127-134 ◽  
Author(s):  
B. K. SAHOO
Keyword(s):  
Scalar Field ◽  
Energy Density ◽  
Time Dependence ◽  
Gravitational Waves ◽  
Hubble Parameter ◽  
Frequency Dependent ◽  
Cosmological Expansion ◽  
Relic Gravitational Waves ◽  
Matter Energy ◽  
Inflationary Models

The spectra of relic gravitational waves produced as a result of cosmological expansion of the inflationary models are derived in Brans–Dicke (BD) theory of gravity. The time dependence of the very early Hubble parameter and matter energy density are derived from frequency-dependent spectrum of relic gravitational waves. Also it is found that Brans–Dicke scalar field contributes to the energy density of relic gravitons.

scholarly journals COSMOLOGICAL CONSTANT PROBING SHAPE MODULI THROUGH LARGE EXTRA DIMENSIONS

2006 ◽  
Vol 21 (15) ◽  
pp. 3095-3109 ◽  
Author(s):  
SATOSHI MATSUDA ◽  
SHIGENORI SEKI
Keyword(s):  
Cosmological Constant ◽  
Extra Dimensions ◽  
Vacuum Energy ◽  
Large Extra Dimensions ◽  
Casimir Energy ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Extra Space ◽  
Kaluza Klein

We consider a compactification of extra dimensions and numerically calculate Casimir energy which is provided by the mass of Kaluza–Klein modes. For the extra space we consider a torus with shape moduli and show that the corresponding vacuum energy is represented as a function of the moduli parameter of the extra dimensions. By assuming that the Casimir energy may be identified with cosmological constant, we evaluate the size of extra dimensions in terms of the recent data given by the Wilkinson Microwave Anisotropy Probe (WMAP) measurement and the supernovae observations. We suggest that the observed cosmological constant may probe the shape moduli of the extra space by the study of the Casimir energy of the compactified extra dimensions.

Experimental tests of an improved 5D Kaluza-Klein theory

2020 ◽  
Vol 35 (02n03) ◽  
pp. 2040027
Author(s):  
Jean Paul Mbelek
Keyword(s):  
Experimental Data ◽  
Scalar Field ◽  
Experimental Tests ◽  
Torsion Pendulum ◽  
Klein Theory ◽  
Kaluza Klein

We recall the motivation for an external scalar field, [Formula: see text], and show how it helps to improve the 5D Kaluza-Klein theory. Various applications of the theory that fit observational or experimental data in the laboratory as well as in the cosmological or astrophysical contexts are mentioned. Special attention is given to the last version of the experiment showing evidence of a torque on a torsion pendulum as predicted by the theory. New arguments that motivate extradimensions are put forward.

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