The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Eliahu Comay - One of the best experts on this subject based on the ideXlab platform.
-
The Significance of an Unnoticed Theoretical Element
OALib, 2020Co-Authors: Eliahu ComayAbstract:Relativistic properties of a Lagrangian Density are compared with those of a Hamiltonian Density. It is proved that a Lagrangian Density and a Hamiltonian Density undergo different Lorentz transformations. This outcome is a theoretical element that has been unnoticed for a very long time. It is also proved that this theoretical element plays a crucial role in the structure of weak interactions theory. In particular, it is shown that the theory that uses this element is overwhelmingly superior over the Standard Model electroweak theory.
-
Relativistic Properties of a Lagrangian and a Hamiltonian in Quantum Theories
Physical Science International Journal, 2019Co-Authors: Eliahu ComayAbstract:Relativistic properties of a Dirac Lagrangian Density are compared with those of a Dirac Hamiltonian Density. Differences stem from the fact that a Lagrangian Density is a Lorentz scalar, whereas a Hamiltonian Density is a 00-component of a second rank tensor, called the energy-momentum tensor. This distinction affects the form of an interaction term of a Dirac particle. In particular, a tensor interaction term of a Dirac Lagrangian Density transforms to a difference between a vector and an axial vector of the corresponding Hamiltonian Density. This outcome shows that fundamental principles can prove the V-A attribute of weak interactions. A further analysis supports these results. Inherent problems of the electroweak theory are discussed.
-
On the Significance of the Fields’ Energy-Momentum Tensor
Physical Science International Journal, 2019Co-Authors: Eliahu ComayAbstract:This work discusses the significance of the energy-momentum tensor of physical fields of an elementary particle. The Noether theorem shows how this tensor can be derived from the Lagrangian Density of a given field. This work proves that the energy-momentum tensor can also be used for a consistency test of a field theory. The results show that the Dirac Lagrangian Density of a spin-1/2 massive particle yields consistent results. On the other hand, problems exist with the present structure of quantum electrodynamics, and with quantum fields of massive particles that are described by a second order differential equation. All problematic results are confirmed by an independent analysis.
-
On the Crucial Role of the Variational Principle in Quantum Theories
Journal of Applied Mathematics and Physics, 2017Co-Authors: Eliahu ComayAbstract:The paper shows that the variational principle serves as an element of the mathematical structure of a quantum theory. The experimentally confirmed properties of the corpuscular-wave duality of a quantum particle are elements of the analysis. A Lagrangian Density that yields the equations of motion of a given quantum theory of a massive particle is analyzed. It is proved that if this Lagrangian Density is a Lorentz scalar whose dimension is then the associated action consistently defines the required phase of the quantum particle. The dimension of this Lagrangian Density proves that also the quantum function has dimension. This result provides new criteria for the acceptability of quantum theories. An examination of the first order Dirac equation demonstrates that it satisfies the new criteria whereas the second order Klein-Gordon equation fails to do that.
-
Gauge Contradictions in the QED Lagrangian Density
Open Access Library Journal, 2017Co-Authors: Eliahu ComayAbstract:This work distinguishes between classical electrodynamics where Maxwell equations and the Lorentz force are used as the theory’s cornerstone (MLE) and electrodynamic theories that are derived from the variational principle (VE). The paper explains the si...
Hongsheng Zhao - One of the best experts on this subject based on the ideXlab platform.
-
refining the mond interpolating function and teves Lagrangian
The Astrophysical Journal, 2006Co-Authors: Hongsheng Zhao, Benoit FamaeyAbstract:The phenomena customarily described with dark matter or modified Newtonian dynamics (MOND) have been argued by Bekenstein to be the consequences of a covariant scalar field, controlled by a free function [related to the MOND interpolating function (g/a0)] in its Lagrangian Density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces a that varies too gradually, and it fits rotation curves less well than the standard MOND interpolating function (x) = x/(1 + x2)1/2. However, the latter varies too sharply and implies an implausible external field effect. These constraints on opposite sides have not yet excluded TeVeS, but they have made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian Density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology.
-
refining mond interpolating function and teves Lagrangian
arXiv: Astrophysics, 2005Co-Authors: Hongsheng Zhao, Benoit FamaeyAbstract:The phenomena customly called Dark Matter or Modified Newtonian Dynamics (MOND) have been argued by Bekenstein (2004) to be the consequences of a covariant scalar field, controlled by a free function (related to the MOND interpolating function) in its Lagrangian Density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces too gradually varying functions and fits rotation curves less well than the standard MOND interpolating function. However, the latter varies too sharply and implies an implausible external field effect (EFE). These constraints on opposite sides have not yet excluded TeVeS, but made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian Density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology, and compare with strong lensing data (see also astro-ph/0509590).
Benoit Famaey - One of the best experts on this subject based on the ideXlab platform.
-
refining the mond interpolating function and teves Lagrangian
The Astrophysical Journal, 2006Co-Authors: Hongsheng Zhao, Benoit FamaeyAbstract:The phenomena customarily described with dark matter or modified Newtonian dynamics (MOND) have been argued by Bekenstein to be the consequences of a covariant scalar field, controlled by a free function [related to the MOND interpolating function (g/a0)] in its Lagrangian Density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces a that varies too gradually, and it fits rotation curves less well than the standard MOND interpolating function (x) = x/(1 + x2)1/2. However, the latter varies too sharply and implies an implausible external field effect. These constraints on opposite sides have not yet excluded TeVeS, but they have made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian Density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology.
-
refining mond interpolating function and teves Lagrangian
arXiv: Astrophysics, 2005Co-Authors: Hongsheng Zhao, Benoit FamaeyAbstract:The phenomena customly called Dark Matter or Modified Newtonian Dynamics (MOND) have been argued by Bekenstein (2004) to be the consequences of a covariant scalar field, controlled by a free function (related to the MOND interpolating function) in its Lagrangian Density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces too gradually varying functions and fits rotation curves less well than the standard MOND interpolating function. However, the latter varies too sharply and implies an implausible external field effect (EFE). These constraints on opposite sides have not yet excluded TeVeS, but made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian Density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology, and compare with strong lensing data (see also astro-ph/0509590).
Zuo-jun Wang - One of the best experts on this subject based on the ideXlab platform.
-
a new Lagrangian Density for all four maxwell s equations
International Journal of Engineering Science, 2010Co-Authors: Cheng-bo Zheng, Zuo-jun WangAbstract:Abstract In 2008 Civelek and Bechteler obtained a Lagrangian Density which can lead to all four Maxwell’s equations by separately using two groups of constraints. In this communication, a new Lagrangian Density is established, which can directly lead to all four Maxwell’s equations by simply using one group of constraints.
-
A new Lagrangian Density for all four Maxwell’s equations
International Journal of Engineering Science, 2010Co-Authors: Cheng-bo Zheng, Zuo-jun WangAbstract:Abstract In 2008 Civelek and Bechteler obtained a Lagrangian Density which can lead to all four Maxwell’s equations by separately using two groups of constraints. In this communication, a new Lagrangian Density is established, which can directly lead to all four Maxwell’s equations by simply using one group of constraints.
R. P. Malik - One of the best experts on this subject based on the ideXlab platform.
-
Symmetry Invariance, Anticommutativity and Nilpotency in BRST Approach to QED: Superfield Formalism
Journal of Physical Mathematics, 2011Co-Authors: R. P. MalikAbstract:We provide the geometrical interpretation for the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry invariance of the Lagrangian Density of a four (3 + 1)-dimensional (4D) interacting U(1) gauge theory within the framework of superfield approach to BRST formalism. This interacting theory, where there is an explicit coupling between the U(1) gauge field and matter (Dirac) fields, is considered on a (4, 2)-dimensional supermanifold parametrized by the four spacetime variables x?(? = 0, 1, 2, 3) and a pair of Grassmannian variables ? and ¯? (with ?2 = ¯?2 = 0, ?¯? + ¯?? = 0). We express the Lagrangian Density and (anti-)BRST charges in the language of the superfields and show that (i) the (anti-)BRST invariance of the 4D Lagrangian Density is equivalent to the translation of the super Lagrangian Density along the Grassmannian direction(s) (? and/or ¯?) of the (4, 2)- dimensional supermanifold such that the outcome of the above translation(s) is zero, and (ii) the anticommutativity and nilpotency of the (anti-)BRST charges are the automatic consequences of our superfield formulation. MSC 2010: 81T80, 81T13, 58J70.
-
Superfield approach to symmetry invariance in quantum electrodynamics with complex scalar fields
Pramana, 2009Co-Authors: R. P. Malik, Bhabani Prasad MandalAbstract:We show that the Grassmannian independence of the super-Lagrangian Density, expressed in terms of the superfields defined on a (4,2)-dimensional supermanifold, is a clear-cut proof for the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST invariance of the corresponding four (3+1)-dimensional (4D) Lagrangian Density that describes the interaction between the U(1) gauge field and the charged complex scalar fields. The above 4D field theoretical model is considered on a (4,2)-dimensional supermanifold parametrized by the ordinary four space-time variables x µ (with µ = 0, 1, 2, 3) and a pair of Grassmannian variables θ and $$ \bar \theta $$ (with θ 2 = $$ \bar \theta $$ 2 = 0, θ $$ \bar \theta $$ + $$ \bar \theta $$ θ = 0). Geometrically, the (anti-)BRST invariance is encoded in the translation of the super-Lagrangian Density along the Grassmannian directions of the above supermanifold such that the outcome of this shift operation is zero.
-
Symmetry invariance, anticommutativity and nilpotency in BRST approach to QED: superfield formalism
arXiv: High Energy Physics - Theory, 2007Co-Authors: R. P. MalikAbstract:We provide the geometrical interpretation for the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry invariance of the Lagrangian Density of a four (3 + 1)-dimensional (4D) interacting U(1) gauge theory within the framework of superfield approach to BRST formalism. This interacting theory, where there is an explicit coupling between the U(1) gauge field and matter (Dirac) fields, is considered on a (4, 2)-dimensional supermanifold parametrized by the four spacetime variables x^\mu (\mu = 0, 1, 2, 3) and a pair of Grassmannian variables \theta and \bar\theta (with \theta^2 = \bar \theta^2 = 0, \theta \bar\theta + \bar \theta \theta = 0$). We express the Lagrangian Density and (anti-)BRST charges in the language of the superfields and show that (i) the (anti-)BRST invariance of the 4D Lagrangian Density is equivalent to the translation of the super Lagrangian Density along the Grassmannian direction(s) (\theta and/or \bar\theta) of the (4, 2)-dimensional supermanifold such that the outcome of the above translation(s) is zero, and (ii) the anticommutativity and nilpotency of the (anti-)BRST charges are the automatic consequences of our superfield formulation.
-
Topological aspects of Abelian gauge theory in superfield formulation
Journal of Physics A: Mathematical and General, 2002Co-Authors: R. P. MalikAbstract:We discuss some aspects of the topological features of a non-interacting two (1+1)-dimensional Abelian gauge theory in the framework of superfield formalism. This theory is described by a BRST invariant Lagrangian Density in the Feynman gauge. We express the local and continuous symmetries, Lagrangian Density, topological invariants and symmetric energy momentum tensor of this theory in the language of superfields by exploiting the nilpotent (anti-)BRST- and (anti-)co-BRST symmetries. In particular, the Lagrangian Density and symmetric energy momentum tensor of this topological theory turn out to be the sum of terms that geometrically correspond to the translations of some local superfields along the Grassmannian directions of the four (2+2)-dimensional supermanifold. In this interpretation, the (anti-)BRST- and (anti-)co-BRST symmetries, that emerge after the imposition of the (dual) horizontality conditions, play a very important role.
