MathDB
Miklos Schweitzer 1951_16

Source:

October 8, 2008
Gausscalculusintegrationadvanced fieldsadvanced fields unsolved

Problem Statement

Let F \mathcal{F} be a surface which is simply covered by two systems of geodesics such that any two lines belonging to different systems form angles of the same opening. Prove that F \mathcal{F} can be developed (that is, isometrically mapped) into the plane.