Fermion localization on branes with non-standard kinetic terms

2018 ◽  
Vol 33 (40) ◽  
pp. 1850235 ◽  
Author(s):  
Masoumeh Moazzen Sorkhi ◽  
Esmaeil Mazani
Keyword(s):  
Scalar Field ◽  
Yukawa Coupling ◽  
Zero Mode ◽  
Scalar Fields ◽  
Coupling Constants ◽  
Warp Factor ◽  
Coupling Mechanism ◽  
Fermion Fields ◽  
Derivative Term ◽  
Fermion Localization

In this paper, by using the Yukawa coupling mechanism, we consider the fermion localization in two types of braneworld models driven by real scalar fields with non-standard dynamics. Because of the existing freedom in the form of the Yukawa coupling, we consider two coupling forms between the background scalar field and spinors where one is arising from the geometry shape of the warp factor and the other is a function of the background scalar field containing a derivative scalar-fermion coupling. With two coupling functions, it is shown that the massless zero mode of fermion fields is localized on both branes with generalized dynamic depending on the values of the coupling constants. However, there is no localized mode when the Yukawa coupling only contains a derivative term of the background scalar field. Furthermore, effects of the parameters of the models on the zero mode and fermion effective potential are addressed.

LOCALIZATION OF MATTERS ON A NON-Z2-SYMMETRIC THICK BRANE

2010 ◽  
Vol 25 (07) ◽  
pp. 511-523
Author(s):  
JUN LIANG ◽  
YI-SHI DUAN
Keyword(s):  
Vector Field ◽  
Scalar Field ◽  
Yukawa Coupling ◽  
Spinor Field ◽  
Zero Mode ◽  
Parallel Transport ◽  
Type Coupling ◽  
Matter Fields

We study localization of various matter fields on a non-Z2-symmetric scalar thick brane in a pure geometric Weyl integrable manifold in which variations in the length of vectors during parallel transport are allowed and a geometric scalar field is involved in its formulation. It is shown that, for spin 0 scalar field, the massless zero mode can be normalized on the brane. Spin 1 vector field cannot be normalized on the brane. And there is no spinor field which can be trapped on the brane for the case of no Yukawa-type coupling. By introducing the appropriate Yukawa coupling, the left or right chiral fermionic zero mode can be localized on the brane.

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 Analytical solutions for fermions on a thick brane with a piecewise and smooth warp factor

2017 ◽  
Vol 32 (35) ◽  
pp. 1750193
Author(s):  
R. R. Landim ◽  
M. O. Tahim ◽  
G. Alencar ◽  
R. N. Costa Filho
Keyword(s):  
Analytical Solutions ◽  
Analytical Methods ◽  
Scalar Fields ◽  
Warp Factor ◽  
Fermion Localization

In this paper, we study analytical solutions for fermion localization in Randall–Sundrum (RS) models. We show that there exist special couplings between scalar fields and fermions giving us discrete massive localizable modes. Besides this we obtain resonances in some models by analytical methods.

scholarly journals Localization of Massive and Massless Fermions on Two-Field Branes

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Farokhtabar ◽  
Ali Tofighi
Keyword(s):  
Scalar Field ◽  
Yukawa Coupling ◽  
Resonance Spectrum ◽  
Brane World ◽  
Field Equations ◽  
World Model ◽  
Massive Fermion ◽  
Considerable Simplification ◽  
Massless Fermions ◽  
Fermion Localization

We study fermion localization and resonances on a special type of brane-world model supporting brane splitting. In such models one can construct multiwall branes which cause considerable simplification in the field equations. We use a polynomial superpotential to construct this brane. The suitable Yukawa coupling between the background scalar field and the localized fermion is determined. The massive fermion resonance spectrum is obtained. The number of resonances is increased for higher values of Yukawa coupling.

scholarly journals Thick brane structures in generalized hybrid metric-Palatini gravity

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
João Luís Rosa ◽  
D. A. Ferreira ◽  
Dionisio Bazeia ◽  
Francisco S. N. Lobo
Keyword(s):  
Scalar Field ◽  
Internal Structure ◽  
Zero Mode ◽  
Scalar Fields ◽  
Gravitational Theory ◽  
Tensor Representation ◽  
The Stability

AbstractIn this work, we study 5-dimensional braneworld scenarios in the scalar-tensor representation of the generalized hybrid metric-Palatini gravitational theory. We start by considering a model for a brane supported purely by the gravitational scalar fields of the theory and then consider other distinct cases where the models are also supported by an additional matter scalar field. We investigate the stability of the gravity sector and show that the models are all robust against small fluctuations of the metric. In particular, in the presence of the additional scalar field, we find that the profile of the gravitational zero mode may be controlled by the parameters of the model, being also capable of developing internal structure.

scholarly journals Renormalization and radiative corrections to masses in a general Yukawa model

2018 ◽  
Vol 33 (03) ◽  
pp. 1850019 ◽  
Author(s):  
M. Fox ◽  
W. Grimus ◽  
M. Löschner
Keyword(s):  
Scalar Potential ◽  
Vacuum Expectation ◽  
Scalar Fields ◽  
Coupling Constants ◽  
Tree Level ◽  
Majorana Fermion ◽  
Dirac Fermions ◽  
Yukawa Couplings ◽  
Fermion Fields ◽  
The Masses

We consider a model with arbitrary numbers of Majorana fermion fields and real scalar fields [Formula: see text], general Yukawa couplings and a [Formula: see text] symmetry that forbids linear and trilinear terms in the scalar potential. Moreover, fermions become massive only after spontaneous symmetry breaking of the [Formula: see text] symmetry by vacuum expectation values (VEVs) of the [Formula: see text]. Introducing the shifted fields [Formula: see text] whose VEVs vanish, [Formula: see text] renormalization of the parameters of the unbroken theory suffices to make the theory finite. However, in this way, beyond tree level it is necessary to perform finite shifts of the tree-level VEVs, induced by the finite parts of the tadpole diagrams, in order to ensure vanishing one-point functions of the [Formula: see text]. Moreover, adapting the renormalization scheme to a situation with many scalars and VEVs, we consider the physical fermion and scalar masses as derived quantities, i.e. as functions of the coupling constants and VEVs. Consequently, the masses have to be computed order by order in a perturbative expansion. In this scheme, we compute the self-energies of fermions and bosons and show how to obtain the respective one-loop contributions to the tree-level masses. Furthermore, we discuss the modification of our results in the case of Dirac fermions and investigate, by way of an example, the effects of a flavor symmetry group.

Scalar particles mass spectrum and localization on FRW branes embedded in a 5D de Sitter bulk

Open Physics ◽  
2014 ◽  
Vol 12 (7) ◽  
Author(s):  
Marina-Aura Dariescu ◽  
Ciprian Dariescu
Keyword(s):  
Scalar Field ◽  
Extra Dimension ◽  
Mass Parameter ◽  
Cosmic Time ◽  
Scalar Fields ◽  
Einstein Equations ◽  
Warp Factor ◽  
De Sitter ◽  
Massive Scalar Field ◽  
Scalar Particles

AbstractIn this paper, we study the scalar fields evolving on a FRW brane embedded in a five-dimensional de Sitter bulk. The scale function and the warp factor, solutions of the Einstein equations, are employed in the five-dimensional Gordon equation describing the massive scalar field, whose wave function depends on the cosmic time and on the extra-dimension. We point out the existence of bounded states and find a minimum value of the effective four-dimensional mass. For the test (scalar) field envelope along the extra-dimension, we derive the corresponding Schrödinger-like equation which is formally that for the Pöschl-Teller potential. Accordingly, we have obtained the quantization law for the mass parameter of the tested scalar field.

scholarly journals CHAOTIC INFLATION ON THE RANDALL–SUNDRUM TWO-BRANE MODEL

2010 ◽  
Vol 25 (31) ◽  
pp. 2697-2713
Author(s):  
KOUROSH NOZARI ◽  
SIAMAK AKHSHABI
Keyword(s):  
Scalar Field ◽  
Field Potential ◽  
Friedmann Equation ◽  
Warp Factor ◽  
Model Parameters ◽  
Stabilization Mechanism ◽  
Brane Model ◽  
Inflation Model ◽  
Bulk Scalar Field ◽  
Chaotic Inflation

We construct an inflation model on the Randall–Sundrum I (RSI) brane where a bulk scalar field stabilizes the inter-brane separation. We study impact of the bulk scalar field on the inflationary dynamics on the brane. We proceed in two different approaches: in the first approach, the stabilizing field potential is directly appeared in the Friedmann equation and the resulting scenario is effectively a two-field inflation. In the second approach, the stabilization mechanism is considered in the context of a warp factor so that there is just one field present that plays the roles of both inflaton and stabilizer. We study constraints imposed on the model parameters from recent observations.

scholarly journals Weak cosmic censorship with self-interacting scalar and bound on charge to mass ratio

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yan Song ◽  
Tong-Tong Hu ◽  
Yong-Qiang Wang
Keyword(s):  
Scalar Field ◽  
Scalar Fields ◽  
Cosmic Censorship ◽  
Mass Ratio ◽  
Quartic Coupling ◽  
Scalar Theory ◽  
Free Scalar ◽  
The One ◽  
Nonzero Scalar ◽  
Large Charge

Abstract We study the model of four-dimensional Einstein-Maxwell-Λ theory minimally coupled to a massive charged self-interacting scalar field, parameterized by the quartic and hexic couplings, labelled by λ and β, respectively. In the absence of scalar field, there is a class of counterexamples to cosmic censorship. Moreover, we investigate the full nonlinear solution with nonzero scalar field included, and argue that these counterexamples can be removed by assuming charged self-interacting scalar field with sufficiently large charge not lower than a certain bound. In particular, this bound on charge required to preserve cosmic censorship is no longer precisely the weak gravity bound for the free scalar theory. For the quartic coupling, for λ < 0 the bound is below the one for the free scalar fields, whereas for λ > 0 it is above. Meanwhile, for the hexic coupling the bound is always above the one for the free scalar fields, irrespective of the sign of β.

scholarly journals FERMIONIC AND SCALAR FIELDS AS SOURCES OF INTERACTING DARK MATTER–DARK ENERGY

2011 ◽  
Vol 20 (13) ◽  
pp. 2543-2558 ◽  
Author(s):  
SAMUEL LEPE ◽  
JAVIER LORCA ◽  
FRANCISCO PEÑA ◽  
YERKO VÁSQUEZ
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Analytical Solution ◽  
Scalar Fields ◽  
Nonminimal Coupling ◽  
Field Equations ◽  
Fermionic Field ◽  
Minimal Coupling ◽  
Constant Type

From a variational action with nonminimal coupling with a scalar field and classical scalar and fermionic interaction, cosmological field equations can be obtained. Imposing a Friedmann–Lemaître–Robertson–Walker (FLRW) metric, the equations lead directly to a cosmological model consisting of two interacting fluids, where the scalar field fluid is interpreted as dark energy and the fermionic field fluid is interpreted as dark matter. Several cases were studied analytically and numerically. An important feature of the non-minimal coupling is that it allows crossing the barrier from a quintessence to phantom behavior. The insensitivity of the solutions to one of the parameters of the model permits it to find an almost analytical solution for the cosmological constant type of universe.

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