On the number of Galois points for a plane curve in positive characteristic, II

Abstract

For a smooth plane curve $$C \subset {\mathbf{P}}^2$$ , we call a point $$P \in {\mathbf{P}}^2$$ a Galois point if the point projection $$\pi_P:C \rightarrow {\mathbf{P}}^1$$ at P is a Galois covering. We study Galois points in positive characteristic. We give a complete classification of the Galois group given by a Galois point and estimate the number of Galois points for C in most cases.