Reducible hyperplane sections of threefolds: two components of sectional genus zero

[摘要] References(16)By using adjunction theory, we describe the smooth complex projective threefolds admitting a simple normal crossing divisor of the form A+B among their hyperplane sections, both components A and B being smooth surfaces with sectional genus 0, and one of them being nef or at worst an exceptional divisor of the first reduction mapping.

[学科分类] 数学（综合）

[关键词] 3-folds;line bundles (ample and spanned);adjunction theory;simple normal crossing divisors;sectional genus;special varieties