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The electromagnetic tensor, conventionally labelled F, is defined as the exterior derivative of the electromagnetic four-potential, A, a differential 1-form: [1] [2] = . Therefore, F is a differential 2-form— an antisymmetric rank-2 tensor field—on Minkowski space. In component form,
The most common description of the electromagnetic field uses two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates.
The electromagnetic stress–energy tensor can be interpreted as the flux density of the momentum four-vector, and is a contravariant symmetric tensor that is the contribution of the electromagnetic fields to the overall stress–energy tensor: = (/ + / / / / / / /), where is the electric permittivity of vacuum, μ 0 is the magnetic ...
This is often described by saying that the electric field and magnetic field are two interrelated aspects of a single object, called the electromagnetic field. Indeed, the entire electromagnetic field can be represented in a single rank-2 tensor called the electromagnetic tensor; see below.
An electromagnetic field (also EM field) is a physical field, mathematical functions of position and time, representing the influences on and due to electric charges. [1] The field at any point in space and time can be regarded as a combination of an electric field and a magnetic field .
An example of a null field is a plane electromagnetic wave in Minkowski space. A non-null field is characterised by P 2 + Q 2 ≠ 0 {\displaystyle P^{2}+Q^{2}\neq \,0} . If P ≠ 0 = Q {\displaystyle P\neq 0=Q} , there exists an inertial reference frame for which either the electric or magnetic field vanishes.
As the term suggests, an EM field consists of two vector fields, an electric field (,) and a magnetic field (,).Both are time-dependent vector fields that in vacuum depend on a third vector field (,) (the vector potential), as well as a scalar field (,)
In the tensor calculus formulation, the electromagnetic tensor F αβ is an antisymmetric covariant order 2 tensor; the four-potential, A α, is a covariant vector; the current, J α, is a vector; the square brackets, [ ], denote antisymmetrization of indices; ∂ α is the partial derivative with respect to the coordinate, x α.