We characterize all (n − 2)-dimensional linear subspaces of P n such that the induced linear projection, when restricted to the rational normal curve, gives a Galois morphism. We give an explicit description of these spaces as a disjoint union of locally closed subvarieties in the Grassmannian G(n − 2, n).

No abstract

No abstract

Given an embedding of a smooth projective curve X of genus g ≥ 1 into P N , we study the locus of linear subspaces of P N of codimension 2 such that projection from said subspace, composed with the embedding, gives a Galois morphism X → P 1 . For genus g ≥ 2 we prove that this locus is a smooth projective variety with components isomorphic to projective spaces. If g = 1 and the embedding is given by a complete linear system, we prove that this locus is also a smooth projective variety whose positivedimensional components are isomorphic to projective bundles over étale quotients of the elliptic curve, and we describe these components explicitly.