\begin{definition}[Definition:Electric Displacement Field]
The '''electric displacement field''' is a vector quantity defined as the electric field strength multiplied by the permittivity of the medium through which it passes:
:$\mathbf D = \varepsilon \mathbf E$
where:
:$\varepsilon$ is the permittivity of the medium
:$\mathbf E$ is the electric field strength
\end{definition}