Titlebook: Enriques Surfaces I; François R. Cossec,Igor V. Dolgachev Book 1989 Birkhäuser Boston 1989 Divisor.Grad.Jacobi.algebra.algebraic surface

过分

包庇

锯齿状

Preliminaries,A morphism f: X → Y of integral schemes over an algebraically closed field K is called a . if f is finite and of degree 2. A double cover is said to be . (resp. . if the corresponding extension of the fields of rational functions is separable (resp. inseparable).

PATRI

Enriques Surfaces: Generalities,Let K be an algebraically closed field of arbitrary characteristic p. In this section we recall the main results of the classification of nonsingular projective surfaces over K. We refer to . for the proofs of all the assertions peculiar to the case of positive characteristic and to general textbooks . for the case of characteristic zero.

伴随而来

Lattices and Root Bases,A . is a free abelian group M of finite rank rk(M) equipped with a symmetric bilinear form ϕ:MxM → .. The value of this form on a pair (x,y)∈MxM will be denoted by x•y. We write x. to denote x•x.

Alpha-Cells

破裂

voluble

Genus One Fibration,Let S be a regular integral scheme of dimension 1, η be its generic point and K = K(η) be its residue field. A projective morphism f: X → S is said to be . if X is regular and irreducible, and the general fibre X. is a geometrically integral regular algebraic curve of arithmetic genus 1.

个阿姨勾引你

https://doi.org/10.1007/978-3-319-50775-0e of them to give the first examples of nonrational algebraic surfaces on which there are no regular differential forms. At the same time a different construction of such surfaces was given by another Italian geometer, no less famous, Guido Castelnuovo. The original construction of Enriques gives a

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