The reductivity of spherical curves Part II: 4-gons

Abstract

The reductivity of a spherical curve represents how reduced the spherical curve is. It is unknown if there exists a spherical curve whose reductivity is four. In this paper we give an unavoidable set for spherical curves with reductivity four by considering 4-gons.

arXiv comment15 pages, 20 figures, to appear in Tokyo Journal of Mathematics

References in corpus (2)

• Knot projections with reductivity two
• Complementary Regions of Knot and Link Diagrams