2012/02/28 by Daigle, Daniel, Hernández, Alejandro Melle
#14C20 #14J26 #Algebraic Geometry (math.AG) #FOS: Mathematics
paper · doi:10.48550/arxiv.1202.6146
A curve C in the projective plane is called non-negative if the self-intersection number of C after the minimal resolution of singularities of C is non-negative. Given a unicuspidal rational plane curve C with singular point P, we study the unique pencil LambdaC on the projective plane satisfying C is in LambdaC and P is its unique base point. We show that the general member of LambdaC is a rational curve if and only if the curve C is non-negative. We also show that in such a case then LambdaC has a dicritical of degree 1. Note that all currently known unicuspidal rational curves C in the projective plane are non-negative.