Gonalidade e Modelos Canônicos de Curvas Racionais Unicuspidais

Abstract

The main goal of this work is the study of the gonality of a curve C. First, in the case where C is not isomorphic to its canonical model C", or equivalently, its dualizing sheaf is just torsion free. This is the case said non Gorenstein, where C" plays the role of a canonical curve. We classify such curves up to genus 5 by means of more general families of curves of arbitrary genus. In the case above, we also study its canonical model. Afterwards, we describe unicuspidal rational curves of genus 5 with hyperelliptic singularities in terms of its gonality. In conclusion, we analyze an upper bound for this invariant for Gorenstein unicuspidal curves.