Examples of unoriented area-minimizing surfaces
Frank Morgan · Transactions of the American Mathematical Society · 1984
A comprehensive study is made of constructions of area-minimizing flat chains modulo two. Many have singularities. For instance, any bounded, area-minimizing submanifold of R n {{\mathbf {R}}^n} occurs as the singular set of some area-minimizing flat chain modulo two in some R N {{\mathbf {R}}^N} .