Confining the scalar field of the Kaluza–Klein monopole

1986 ◽  
Vol 64 (5) ◽  
pp. 637-640 ◽  
Author(s):  
G. Kunstatter ◽  
D. Vincent
Keyword(s):  
Boundary Layer ◽  
Scalar Field ◽  
Effective Stress ◽  
Thin Boundary Layer ◽  
Stress Energy ◽  
Inherent Problem ◽  
Kaluza Klein

A discussion is given of the Kaluza–Klein monopole and the inherent problem associated with its scalar field. A model that achieves a confinement of this scalar field is presented, whereby a thin boundary layer is imposed on the monopole geometry allowing an exterior geometry with a constant scalar field to be attached. The Gauss–Codazzi formalism then puts strong constraints on the effective stress energy of the boundary.

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 Thick branes in the scalar–tensor representation of f(R, T) gravity

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
João Luís Rosa ◽  
Matheus A. Marques ◽  
Dionisio Bazeia ◽  
Francisco S. N. Lobo
Keyword(s):  
Scalar Field ◽  
Matter Field ◽  
Energy Tensor ◽  
Tensor Representation ◽  
Observable Universe ◽  
Brane Model ◽  
Gravitational Fields ◽  
Stress Energy ◽  
Tensor Representations ◽  
The Stability

AbstractBraneworld scenarios consider our observable universe as a brane embedded in a five-dimensional bulk. In this work, we consider thick braneworld systems in the recently proposed dynamically equivalent scalar–tensor representation of f(R, T) gravity, where R is the Ricci scalar and T the trace of the stress–energy tensor. In the general $$f\left( R,T\right) $$ f R , T case we consider two different models: a brane model without matter fields where the geometry is supported solely by the gravitational fields, and a second model where matter is described by a scalar field with a potential. The particular cases for which the function $$f\left( R,T\right) $$ f R , T is separable in the forms $$F\left( R\right) +T$$ F R + T and $$R+G\left( T\right) $$ R + G T , which give rise to scalar–tensor representations with a single auxiliary scalar field, are studied separately. The stability of the gravitational sector is investigated and the models are shown to be stable against small perturbations of the metric. Furthermore, we show that in the $$f\left( R,T\right) $$ f R , T model in the presence of an extra matter field, the shape of the graviton zero-mode develops internal structure under appropriate choices of the parameters of the model.

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 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.

scholarly journals Flow around a Circular Cone in a Thin Boundary Layer (Consideration on a Front Stagnation Point)

2008 ◽  
Vol 74 (740) ◽  
pp. 803-810 ◽  
Author(s):  
Takatsugu KAMEDA ◽  
Tetsuya SUMIDA ◽  
Shinsuke MOCHIZUKI ◽  
Hideo OSAKA
Keyword(s):  
Boundary Layer ◽  
Stagnation Point ◽  
Circular Cone ◽  
Thin Boundary Layer

scholarly journals ANALYSIS OF UNBALANCED BLACK RING SOLUTIONS WITHIN THE QUASILOCAL FORMALISM

2011 ◽  
Vol 20 (04) ◽  
pp. 581-591 ◽  
Author(s):  
ZHENXING LIU ◽  
ZEQIAN CHEN
Keyword(s):  
Black Ring ◽  
Energy Tensor ◽  
Stress Energy Tensor ◽  
Asymptotically Flat ◽  
Black Rings ◽  
Balance Condition ◽  
Extra Term ◽  
Stress Energy ◽  
Boundary Stress ◽  
Kaluza Klein

We investigate the properties of rotating asymptotically flat black ring solutions in five-dimensional Einstein–Maxwell-dilaton gravity with the Kaluza–Klein coupling. Within the quasilocal formalism, the balance condition for these solutions is derived by using the conservation of the renormalized boundary stress–energy tensor, which is a new method proposed by Astefanesei and his collaborators. We also study the thermodynamics of unbalanced black rings. The conserved charges and the thermodynamical quantities are computed. Due to the existence of a conical singularity in the boundary, these quantities differ from the original regular ones. It is shown that the Smarr relation and the quantum statistical relation are still satisfied. However, we get an extra term in the first law of thermodynamics. As the balance condition is imposed this extra term vanishes.

Effect of Carbon Nanotube-Phosphinate Ionic Liquid Thin Boundary Layer on the Tribological Behavior of Aluminum Alloy in Steel-on-Aluminum Contact

2018 ◽  
Author(s):  
Miguel A. Gutierrez ◽  
Michael Gydesen ◽  
Caitlin Marcellus ◽  
Ivan Puchades ◽  
Brian Landi ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Ionic Liquid ◽  
Aluminum Alloy ◽  
Optical Microscopy ◽  
Coefficient Of Friction ◽  
Tribological Behavior ◽  
Sliding Contact ◽  
Wear Volume ◽  
Thin Boundary Layer ◽  
Boundary Film

In this study, the tribological behavior of the Trihexyl tetradecylphosphonium-bis(2,4,4-trimethylpentyl)phosphinate [THTDP][Phos] ionic liquid with and without single-wall carbon nanotubes (SWCNT) dispersion as a thin boundary layer was intended for investigation. However, the surface heat treatment process was not sufficient to form a thin film on the sample surfaces. Thus, in each test condition, the lubricating agents were used as external (liquid) lubricants. Specifically, [THTDP][Phos] and ([THTDP][Phos]+0.1 wt.% SWCNT) boundary film layers were applied on 6061-T6 aluminum alloy disk samples and tested under sliding contact with 1.5 mm diameter 420C stainless steel balls using a ball-on-flat linearly reciprocating tribometer. A commercially available Mobil Super 10W-40 engine oil (MS10W40) was also tested and used as this investigation’s datum. The tribological behavior of [THTDP][Phos] and ([THTDP][Phos]+SWCNT) boundary film layers was analyzed via wear volume calculations from optical microscopy measurements, as well as by observation of the transient coefficient of friction (COF) obtained through strain gauge measurements made directly from the reciprocating member of the tribometer. Results indicate the potential for reduction of wear volume and coefficient of friction in the IL lubricated steel-on-aluminum sliding contact through (SWCNT) dispersion in the ionic liquid. Wear results are based on measurements obtained using optical microscopy (OM). Results discussed display improved tribological performance for both [THTDP][Phos] and ([THTDP][Phos]+SWCNT) over baseline MS10W40 oil lubricant for both roughness values tested for the steel-on-aluminum contact. No measurable improvements were observed between [THTDP][Phos] and ([THTDP][Phos]+SWCNT) tests.

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