A minimal surface stretched over a $4$-sided polygon. It is one of the first more general solutions to the Plateau problem. Analytically it is expressed using the Christoffel–Schwarz formula. It was first studied by B. Riemann (1872) and H.A. Schwarz (1874).
|[a1]||J.C.C. Nitsche, "Vorlesungen über Minimalflächen" , Springer (1975)|
Riemann–Schwarz surface. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Riemann%E2%80%93Schwarz_surface&oldid=22988