The Square peg problem

Abstract

[en] The Square Peg Problem, also known as Toeplitz’ Conjecture, is an unsolved problem in the mathematical areas of geometry and topology which states the following: every Jordan curve in the plane inscribes a square. Although it seems like an innocent statement, many authors throughout the last century have tried, but failed, to solve it. It is proved to be true with certain “smoothness conditions” applied on the curve, but the general case is still an open problem. We intend to give a general historical view of the known approaches and, more specifically, focus on an important result that allowed the Square Peg Problem to be true for a great sort of curves: Walter Stromquist’s theorem.