The electric flux density D is given by
div D=ρf
where ρ
f is the volume density of
free charges.
D is related to the electric field E and the polarization P via
D=εOE+P
The time
derivative of
D is known as the
displacement current which appears in one of
Maxwell's equations.
curl H = J + dD/dt
The equivalent magnetic quantity to D is the magnetic flux density, B