Neumann boundary-value problem
= Neumann boundary-value problem
{c}
A <boundary value problem> with prescribed outward <normal derivative>, or the associated weighted flux, on the boundary. Its boundary data are <Neumann boundary data>. For an elliptic divergence-form operator without a zeroth-order term, integration over the domain imposes a compatibility condition between total source and boundary flux. A connected domain generally leaves a constant undetermined, fixed by a mean or reference value.