Sphere and circle theorems involving surface discontinuities of potential

Generalized Circle and Sphere Theorems for Inviscid and Viscous Flows

“…The two-dimensional counterpart of the Weiss sphere theorem was obtained earlier by Milne-Thomson [23,24] which is widely known as the circle theorem. These basic theorems were extended by several authors in order to satisfy various boundary conditions that arise in various fields such as hydrodynamics, heat, magnetism and electrostatics [19,28,29,30,38,39]. The Kelvin's inversion was the key idea in those works involving a single spherical or a circular boundary.…”