%0 Journal Article %T The gonality and the Clifford index of curves on a toric surface %A Ryo Kawaguchi %J Mathematics %D 2013 %I arXiv %X We determine the gonality and the Clifford index for curves on a compact smooth toric surface. Moreover, it is shown that their gonality are computed by pencils on the ambient surface. From the geometrical view point, this means that the gonality can be read off from the lattice polygon associated to the curve. %U http://arxiv.org/abs/1310.5213v1