Ruled variety
In algebraic geometry, a variety over a field k is ruled if it is birational to the product of the projective line with some variety over k. A variety is uniruled if it is covered by a family of rational curves. (More precisely, a variety X is uniruled if there is a variety Y and a dominant rational map Y × P1 – → X which does not factor through the projection to Y.) The concept arose from the ruled surfaces of 19th-century geometry, meaning surfaces in affine space or projective space which are covered by lines. Uniruled varieties can be considered to be relatively simple among all varieties, although there are many of them.
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Ruled variety
In algebraic geometry, a variety over a field k is ruled if it is birational to the product of the projective line with some variety over k. A variety is uniruled if it is covered by a family of rational curves. (More precisely, a variety X is uniruled if there is a variety Y and a dominant rational map Y × P1 – → X which does not factor through the projection to Y.) The concept arose from the ruled surfaces of 19th-century geometry, meaning surfaces in affine space or projective space which are covered by lines. Uniruled varieties can be considered to be relatively simple among all varieties, although there are many of them.
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In algebraic geometry, a varie ...... though there are many of them.
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代数幾何学では、体 k 上の代数多様体が線織多様体(rule ...... 、すべての多様体の中では比較的単純であると考えるられている。
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In algebraic geometry, a varie ...... though there are many of them.
@en
代数幾何学では、体 k 上の代数多様体が線織多様体(rule ...... 、すべての多様体の中では比較的単純であると考えるられている。
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Ruled variety
@en
単線織多様体
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선직다양체
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