There is also an alternative, electrostatic interpretation of quadrature domains: a domain D is a quadrature domain if a uniform distribution of electric charge on D creates the same electrostatic field outside D as does a k-tuple of point charges at the points z1, …, zk.
A quadrature domain D can be interpreted in an alternative way through electrostatics: if a uniform electric charge is distributed across D, it produces the same electrostatic field outside D as would k distinct point charges located at z1, ..., zk.