scholarly journals The relation between Maxwell, Dirac, and the Seiberg-Witten equations

2003 ◽  
Vol 2003 (43) ◽  
pp. 2707-2734 ◽  
Author(s):  
Waldyr A. Rodrigues
Keyword(s):  
Spinor Field ◽  
Maxwell Equations ◽  
Degrees Of Freedom ◽  
Minkowski Spacetime ◽  
Magnetic Monopoles ◽  
The Other ◽  
Field Equations ◽  
Maxwell Theory ◽  
Hertz Potential ◽  
Form Field

We discuss unsuspected relations between Maxwell, Dirac, and the Seiberg-Witten equations. First, we present the Maxwell-Dirac equivalence (MDE) of the first kind. Crucial to that proposed equivalence is the possibility of solving for ψ (a representative on a given spinorial frame of a Dirac-Hestenes spinor field) the equation F=ψγ21ψ˜, where F is a given electromagnetic field. Such task is presented and it permits to clarify some objections to the MDE which claim that no MDE may exist because F has six (real) degrees of freedom and ψ has eight (real) degrees of freedom. Also, we review the generalized Maxwell equation describing charges and monopoles. The enterprise is worth, even if there is no evidence until now for magnetic monopoles, because there are at least two faithful field equations that have the form of the generalized Maxwell equations. One is the generalized Hertz potential field equation (which we discuss in detail) associated with Maxwell theory and the other is a (nonlinear) equation (of the generalized Maxwell type) satisfied by the 2-form field part of a Dirac-Hestenes spinor field that solves the Dirac-Hestenes equation for a free electron. This is a new result which can also be called MDE of the second kind. Finally, we use the MDE of the first kind together with a reasonable hypothesis to give a derivation of the famous Seiberg-Witten equations on Minkowski spacetime. A physical interpretation for those equations is proposed.

scholarly journals Pure electromagnetic-gravitational interaction in Hořava–Lifshitz theory at the kinetic conformal point

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Alvaro Restuccia ◽  
Francisco Tello-Ortiz
Keyword(s):  
Maxwell Equations ◽  
Degrees Of Freedom ◽  
Gravitational Interaction ◽  
Gravitational Theory ◽  
Higher Order ◽  
Coupling Constants ◽  
Field Equations ◽  
Maxwell Theory ◽  
Anisotropic Field ◽  
Low Energies

Abstract We introduce the electromagnetic-gravitational coupling in the Hořava–Lifshitz framework, in $$3+1$$3+1 dimensions, by considering the Hořava–Lifshitz gravity theory in $$4+1$$4+1 dimensions at the kinetic conformal point and then performing a Kaluza–Klein reduction to $$3+1$$3+1 dimensions. The action of the theory is second order in time derivatives and the potential contains only higher order spacelike derivatives up to $$z=4$$z=4, z being the critical exponent. These terms include also higher order derivative terms of the electromagnetic field. The propagating degrees of freedom of the theory are exactly the same as in the Einstein–Maxwell theory. We obtain the Hamiltonian, the field equations and show consistency of the constraint system. The conformal kinetic point is protected from quantum corrections by a second class constraint. At low energies the theory depends on two coupling constants, $$\beta $$β and $$\alpha $$α. We show that the anisotropic field equations for the gauge vector is a deviation of the covariant Maxwell equations by a term depending on $$\beta -1$$β-1. Consequently, for $$\beta =1$$β=1, Maxwell equations arise from the anisotropic theory at low energies. We also prove that the anisotropic electromagnetic-gravitational theory at the IR point $$\beta =1$$β=1, $$\alpha =0$$α=0, is exactly the Einstein–Maxwell theory in a gravitational gauge used in the ADM formulation of General Relativity.

scholarly journals Quaternionic Approach to Dual Magnetohydrodynamics of Dyonic Cold Plasma

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
B. C. Chanyal ◽  
Mayank Pathak
Keyword(s):  
Wave Equation ◽  
Cold Plasma ◽  
Maxwell Equations ◽  
Magnetic Monopoles ◽  
Alfven Wave ◽  
Vorticity Field ◽  
Field Equations ◽  
Continuity Equations ◽  
Fields Equations ◽  
Quaternionic Formulation

The dual magnetohydrodynamics of dyonic plasma describes the study of electrodynamics equations along with the transport equations in the presence of electrons and magnetic monopoles. In this paper, we formulate the quaternionic dual fields equations, namely, the hydroelectric and hydromagnetic fields equations which are an analogous to the generalized Lamb vector field and vorticity field equations of dyonic cold plasma fluid. Further, we derive the quaternionic Dirac-Maxwell equations for dual magnetohydrodynamics of dyonic cold plasma. We also obtain the quaternionic dual continuity equations that describe the transport of dyonic fluid. Finally, we establish an analogy of Alfven wave equation which may generate from the flow of magnetic monopoles in the dyonic field of cold plasma. The present quaternionic formulation for dyonic cold plasma is well invariant under the duality, Lorentz, and CPT transformations.

GEOMETRIZATION OF ELECTROMAGNETISM IN TETRAD-SPIN-CONNECTION GRAVITY

2009 ◽  
Vol 24 (06) ◽  
pp. 431-442 ◽  
Author(s):  
NIKODEM J. POPŁAWSKI
Keyword(s):  
Variational Principle ◽  
Electromagnetic Fields ◽  
Spinor Field ◽  
Maxwell Equations ◽  
Electromagnetic Coupling ◽  
Ricci Scalar ◽  
Spin Connection ◽  
Electromagnetic Potential ◽  
Field Equations ◽  
Generally Covariant

The metric-affine Lagrangian of Ponomarev and Obukhov for the unified gravitational and electromagnetic fields is linear in the Ricci scalar and quadratic in the tensor of homothetic curvature. We apply to this Lagrangian the variational principle with the tetrad and spin connection as dynamical variables and show that, in this approach, the field equations are the Einstein–Maxwell equations if we relate the electromagnetic potential to the trace of the spin connection. We also show that, as in the Ponomarev–Obukhov formulation, the generally covariant Dirac Lagrangian gives rise to the standard spinor source for the Einstein–Maxwell equations, while the spinor field obeys the nonlinear Heisenberg–Ivanenko equation with the electromagnetic coupling. We generalize that formulation to spinors with arbitrary electric charges.

scholarly journals COLLISION OF HIGH FREQUENCY PLANE GRAVITATIONAL AND ELECTROMAGNETIC WAVES

2003 ◽  
Vol 12 (08) ◽  
pp. 1459-1473 ◽  
Author(s):  
P. A. HOGAN ◽  
D. M. WALSH
Keyword(s):  
Gravitational Waves ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Degrees Of Freedom ◽  
Geometrical Optics ◽  
Field Equations ◽  
Maxwell Theory ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Plane Gravitational Waves

We study the head-on collision of linearly polarized, high frequency plane gravitational waves and their electromagnetic counterparts in the Einstein–Maxwell theory. The post-collision space-times are obtained by solving the vacuum Einstein and Einstein–Maxwell field equations in the geometrical optics approximation. The head-on collisions of all possible pairs of these systems of waves is described and the results are then generalized to nonlinearly polarized waves which exhibit the maximum two degrees of freedom of polarization.

The free field

2018 ◽  
Author(s):  
Nathalie Deruelle ◽  
Jean-Philippe Uzan
Keyword(s):  
Gauge Invariance ◽  
Maxwell Equations ◽  
Degrees Of Freedom ◽  
Vector Fields ◽  
Initial Conditions ◽  
Free Field ◽  
Maxwell Theory ◽  
Gauge Invariant ◽  
Massive Vector ◽  
The One

This chapter studies the structure of Maxwell’s equations in a vacuum and the action from which they are derived, while emphasizing the consequences of their gauge invariance. Gauge invariance, on the one hand, allows one of the components of the magnetic potential to be chosen freely. Here, the chapter shows how the gauge-invariant version of the Maxwell equations in the vacuum can also be derived directly by extremizing. On the other hand, the chapter argues that gauge invariance imposes a constraint on the initial conditions such that in the end the general solution has only two ‘degrees of freedom’. Finally, the chapter develops the Hamiltonian formalisms in the Maxwell theory and compares them to the formalisms using non-gauge-invariant or massive vector fields.

FRW viscous fluid cosmological model with time-dependent inhomogeneous equation of state

2017 ◽  
Vol 15 (01) ◽  
pp. 1830001 ◽  
Author(s):  
G. S. Khadekar ◽  
Deepti Raut
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Quadratic Form ◽  
State Parameter ◽  
The Other ◽  
Time Dependent ◽  
Inhomogeneous Equation ◽  
Field Equations ◽  
Equation Of State Parameter ◽  
Viscous Models

In this paper, we present two viscous models of non-perfect fluid by avoiding the introduction of exotic dark energy. We consider the first model in terms of deceleration parameter [Formula: see text] has a viscosity of the form [Formula: see text] and the other model in quadratic form of [Formula: see text] of the type [Formula: see text]. In this framework we find the solutions of field equations by using inhomogeneous equation of state of form [Formula: see text] with equation of state parameter [Formula: see text] is constant and [Formula: see text].

On Conformally Covariant Spinor Field Equations

1972 ◽  
Vol 50 (18) ◽  
pp. 2100-2104 ◽  
Author(s):  
Mark S. Drew
Keyword(s):  
Minkowski Space ◽  
Invariant Mass ◽  
Spinor Field ◽  
Dimensional Space ◽  
Flat Space ◽  
Field Equations ◽  
First Order ◽  
Conformally Invariant ◽  
Spinor Fields

Conformally covariant equations for free spinor fields are determined uniquely by carrying out a descent to Minkowski space from the most general first-order rotationally covariant spinor equations in a six-dimensional flat space. It is found that the introduction of the concept of the "conformally invariant mass" is not possible for spinor fields even if the fields are defined not only on the null hyperquadric but over the entire manifold of coordinates in six-dimensional space.

scholarly journals GENERALIZED EINSTEIN–MAXWELL FIELD EQUATIONS IN THE PALATINI FORMALISM

2013 ◽  
Vol 22 (04) ◽  
pp. 1350017 ◽  
Author(s):  
GINÉS R. PÉREZ TERUEL
Keyword(s):  
Electromagnetic Field ◽  
Algebraic Equation ◽  
Ricci Tensor ◽  
Maxwell Equations ◽  
Natural Generalization ◽  
New Method ◽  
Maxwell Field ◽  
Field Equations ◽  
Palatini Formalism

We derive a new set of field equations within the framework of the Palatini formalism. These equations are a natural generalization of the Einstein–Maxwell equations which arise by adding a function [Formula: see text], with [Formula: see text] to the Palatini Lagrangian f(R, Q). The result we obtain can be viewed as the coupling of gravity with a nonlinear extension of the electromagnetic field. In addition, a new method is introduced to solve the algebraic equation associated to the Ricci tensor.

Footbridges as an important part of a system: the context as an experience

2021 ◽  
Author(s):  
Toon Maas ◽  
Mohamad Tuffaha ◽  
Laurent Ney
Keyword(s):  
Design Process ◽  
Degrees Of Freedom ◽  
The Other ◽  
Infrastructure Projects ◽  
Good Design ◽  
Cultural Processes ◽  
The Relationship

<p>“A bridge has to be designed”. Every bridge is the exploration of all degrees of a freedom of a project: the context, cultural processes, technology, engineering and industrial skills. A successful bridge aims to dialogue with these degrees of freedom to achieve a delicate equilibrium, one that invites the participation of its users and emotes new perceptions for its viewers. In short, a good design “makes the bridge talk.”</p><p>Too often, the bridge, as an object, is reduced to its functionality. Matters of perceptions and experiences of the users are often not considered in the design process; they are relegated to levels of chance or treated as simple decorative matter. The longevity of infrastructure projects, in general, and bridges, in particular, highlights the deficiencies of such an approach. The framework to design bridges must include historical, cultural, and experiential dimensions. Technology and engineering are of paramount importance but cannot be considered as “an end in themselves but a means to an end”. This paper proposes to discuss three projects by Ney &amp; Partners that illustrate such a comprehensive exploration approach to footbridge design: the Poissy and Albi crossings and the Tintagel footbridge.</p><p>The footbridges of Poissy and Albi dialogue most clearly with their historical contexts, reconfiguring the relationship between old and new in the materiality and typology use. In Tintagel, legend replaces history. Becoming a metaphor for the void it crosses, the Tintagel footbridge illustrates the delicate dialogue of technology and engineering on one side and imagination and experience on the other.</p>

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