Algebraic geometry

Contraction morphism

In algebraic geometry, a contraction morphism is a surjective projective morphism between normal projective varieties (or projective schemes) such that or, equivalently, the geometric fibers are all connected (Zariski's connectedness theorem). It is also commonly called an algebraic fiber space, as it is an analog of a fiber space in algebraic topology. By the Stein factorization, any surjective projective morphism is a contraction morphism followed by a finite morphism. Examples include ruled surfaces and Mori fiber spaces. (Wikipedia).

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From playlist Relativity

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From playlist Physics - Special Relativity

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From playlist Physics - Special Relativity

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From playlist Algebraic Structures in Perturbative Quantum Field Theory: a conference in honour of Dirk Kreimer's 60th birthday

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Related pages

Birational geometry | Flip (mathematics) | Zariski's connectedness theorem | Algebraic topology | Algebraic geometry | Stein factorization | Ruled surface | Castelnuovo's contraction theorem