scholarly journals Generation of new symmetries from explicit symmetry breaking

2021 ◽  
Vol 2090 (1) ◽  
pp. 012052
Author(s):  
N. Dimakis
Keyword(s):  
Symmetry Breaking ◽  
Finsler Space ◽  
Relativistic Particle ◽  
Lorentz Violation ◽  
Conformal Killing ◽  
Integrals Of Motion ◽  
Continuous Parameter ◽  
First Case ◽  
Conformal Killing Vectors ◽  
Different Types

Abstract We study how the explicit symmetry breaking, through a continuous parameter in the Lagrangian, can actually lead to the creation of different types of symmetries. As examples we consider the motion of a relativistic particle in a curved background, where a nonzero mass breaks the symmetry of the conformal algebra of the metric, and the motion in a Bogoslovsky-Finsler space-time, where a Lorentz violation takes place. In the first case, new nonlocal conserved charges emerge in the place of those which were previously generated by the conformal Killing vectors, while in the second, rational in the momenta integrals of motion appear to substitute the linear expressions corresponding to those boosts which fail to be symmetries.

ON A PERFECT FLUID K¨ AHLER SPACETIME

2016 ◽  
Vol 12 (3) ◽  
pp. 4350-4355
Author(s):  
VIBHA SRIVASTAVA ◽  
P. N. PANDEY
Keyword(s):  
Field Equation ◽  
Perfect Fluid ◽  
Sectional Curvature ◽  
Einstein Field Equation ◽  
Cosmological Term ◽  
Conformal Killing ◽  
Killing Vectors ◽  
Projectively Flat ◽  
Conformal Killing Vectors

The object of the present paper is to study a perfect fluid K¨ahlerspacetime. A perfect fluid K¨ahler spacetime satisfying the Einstein field equation with a cosmological term has been studied and the existence of killingand conformal killing vectors have been discussed. Certain results related to sectional curvature for pseudo projectively flat perfect fluid K¨ahler spacetime have been obtained. Dust model for perfect fluid K¨ahler spacetime has also been studied.

The Chemical Decontamination Process Intensification, using Ultrasounds

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Eugenia Pantru ◽  
Gheorghit Jinescu ◽  
Rozalia R�dulescu ◽  
Antoneta Filcenco Olteanu ◽  
Cosmin Jinescu
Keyword(s):  
Chemical Composition ◽  
Process Intensification ◽  
Sulphuric Acid Solution ◽  
Liquid Ratio ◽  
Polluted Soils ◽  
Chemical Decontamination ◽  
First Case ◽  
Ultrasound Field ◽  
Different Types ◽  
Main Factors

This paper presents an intensive procedure used for the decontamination of the soils, which were radioactively contaminated by uranium, due to the occurrence of some antropic accidents, in order to limit the area�s pollution. The procedure used for the chemical decontamination of the polluted soils was the washing one and the decontamination degree is comparatively presented depending on the ultrasounds� presence and absence. The lab testes were performed on five types of soils , which were characterized from the granulometric, structural and chemical composition viewpoint, all these aspects represent the main factors, which determine the applied decontamination procedure�s limits and performances correlated with its utilization costs. The decontamination procedure�s kinetics for each type of soils was analyzed, using successively three different types of reagents (water, 0.1 M sulphuric acid solution and chloro-sodic solution � 100 g/L sodium chloride + 10 g/L sodium carbonate in water) for a solid to liquid ratio of 1:2, during 2 h, at a temperature of 20oC in a mechanic stirring system respectively in ultrasounds field. It was observed that the decontamination degree increases with up to 15-20% in case of the ultrasound field utilization comparing to the first case.

INHERITING SPACELIKE CONFORMAL KILLING VECTORS IN STRING COSMOLOGY

2003 ◽  
Vol 12 (05) ◽  
pp. 885-892 ◽  
Author(s):  
HÜSNÜ BAYSAL
Keyword(s):  
General Relativity ◽  
Cosmic Strings ◽  
String Cosmology ◽  
Conformal Killing ◽  
Killing Vectors ◽  
Conformal Killing Vectors

We study the consequences of the existence of spacelike conformal Killing vectors (SpCKV) parallel to xa for cosmic strings and string fluid in the context of general relativity. The inheritance symmetries of the cosmic strings and string fluid are discussed in the case of SpCKV. Furthermore we examine proper homothetic spacelike Killing vectors for the cosmic strings and string fluid.

Amplitude Modulation and Symmetry Breaking Bifurcation in Micro Devices

2012 ◽  
Author(s):  
Z. C. Feng ◽  
Mahmoud Almasri
Keyword(s):  
Symmetry Breaking ◽  
Numerical Simulations ◽  
Amplitude Modulation ◽  
Dynamic Responses ◽  
Symmetric Structure ◽  
Different Types ◽  
Asymmetric Responses ◽  
Symmetric Response ◽  
Symmetry Breaking Bifurcation

Designs of many micro devices take advantage of the symmetry for better performance, immunity to noise, and for simpler analysis. When a symmetric structure is subjected to symmetric forcing, the symmetric response can become unstable leading to asymmetric responses. The occurrence of symmetry breaking bifurcation leads to complicated dynamic responses which often result in less desirable performances. In this paper, we obtain analytical criteria for the onset of symmetry breaking bifurcations. We also conduct numerical simulations to demonstrate different types of asymmetric dynamic responses resulting from the symmetry breaking bifurcation. In particular, we show the occurrence of amplitude modulated motions in such systems.

The Hertzian Spectrum of Rubber and Its Micellar Constitution

1946 ◽  
Vol 19 (4) ◽  
pp. 1085-1087
Author(s):  
Pierre Girard ◽  
Paul Abadie
Keyword(s):  
Dielectric Constant ◽  
Electric Field ◽  
Wave Length ◽  
Structural Features ◽  
Loss Angle ◽  
First Case ◽  
Dipolar Molecules ◽  
Alternating Electric Field ◽  
Different Types ◽  
Absorption And Dispersion

Abstract The spectra which were studied lie within the region of hertzian frequencies, and can be represented either by dispersion curves showing the dielectric constant of the substance as a function of the frequency (or wave length λ), or by absorption curves showing the loss angle as a function of this frequency. These two types of curves represent the same phenomenon, i.e., orientation of the dipolar molecules in the alternating electric field, in accordance with the theory of Debye. The spectra and their interpretation depend chiefly on whether the molecules are crystalloid with relatively small and similar dimensions, or are colloidal, with large and unequal dimensions. In the first case, the spectra gives evidence chiefly on the form of the molecules and their structural features. Dilution in a nonpolar solvent shows for certain dipolar compounds, e.g., alcohol, considerable deformations, which differ according to the solvent. In the case of colloids, e.g., rubber, which has a permanent moment, the spectra and the meaning of these spectra are far different. In this case the spectra indicate that the absorption and dispersion values in the hertzian region are closely related to the micellar constitution, i.e., to the different types of micelles, to their size, and to the proportion of each type.

scholarly journals Cosmological constant in chameleon Brans–Dicke theory

2019 ◽  
Vol 28 (01) ◽  
pp. 1950022 ◽  
Author(s):  
Yousef Bisabr
Keyword(s):  
Exact Solution ◽  
Scalar Field ◽  
Cosmological Constant ◽  
Exact Solutions ◽  
Effective Mass ◽  
Potential Function ◽  
Power Law ◽  
Exponential Form ◽  
First Case ◽  
Different Types

We consider a generalized Brans–Dicke model in which the scalar field has a self-interacting potential function. The scalar field is also allowed to couple nonminimally with the matter part. We assume that it has a chameleon behavior in the sense that it acquires a density-dependent effective mass. We consider two different types of matter systems which couple with the chameleon, dust and vacuum. In the first case, we find a set of exact solutions when the potential has an exponential form. In the second case, we find a power-law exact solution for the scale factor. In this case, we will show that the vacuum density decays during expansion due to coupling with the chameleon.

scholarly journals Novel thick brane solutions with U(1) symmetry breaking

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Marzieh Peyravi ◽  
Nematollah Riazi ◽  
Francisco S. N. Lobo
Keyword(s):  
Symmetry Breaking ◽  
Scalar Fields ◽  
Einstein Tensor ◽  
Vacuum Structure ◽  
Different Types ◽  
Dimensional Gravity ◽  
Breaking Parameter ◽  
Symmetry Breaking Term ◽  
The Stability ◽  
Breaking Term

AbstractIn this work, using two scalar fields ($$\phi $$ ϕ , $$\psi $$ ψ ) coupled to 4 + 1 dimensional gravity, we construct novel topological brane solutions through an explicit U(1) symmetry breaking term. The potential of this model is constructed so that two distinct degenerate vacua in the $$\phi $$ ϕ field exist, in analogy to the $$\phi ^{4}$$ ϕ 4 potential. Therefore, brane solutions appear due to the vacuum structure of the $$\phi $$ ϕ field. However, the topology and vacuum structure in the $$\psi $$ ψ direction depends on the symmetry breaking parameter $$\beta ^{2}$$ β 2 , which leads to different types of branes. As a result, one can interpret the present model as a combination of a $$\phi ^{4}$$ ϕ 4 brane with an auxiliary field, which leads to deviations from the $$\phi ^{4}$$ ϕ 4 system with the brane achieving a richer internal structure. Furthermore, we analyse in detail the behaviour of the superpotentials, the warp factors, the Ricci and Kretschmann scalars and the Einstein tensor components. In addition to this, we explore the stability of the brane in terms of the free parameters of the model. The analysis presented here complements previous work and is sufficiently novel to be interesting.

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