paper

Invariants of curves in RP^2 and R^2

arXiv:math/0602003 · doi:10.2140/agt.2006.6.2175

Abstract

There is an elegant relation found by Fabricius-Bjerre [Math. Scand 40 (1977) 20--24] among the double tangent lines, crossings, inflections points, and cusps of a singular curve in the plane. We give a new generalization to singular curves in RP^2. We note that the quantities in the formula are naturally dual to each other in RP^2, and we give a new dual formula.

This is the version published by Algebraic & Geometric Topology on 19 November 2006

Invariants of curves in RP^2 and R^2 · wovepaper