The Noether-lefschetz Theorem
نویسندگان
چکیده
Earlier we defined the class group ClX of Weil divisors for an algebraic varietyX and the Cartier class group CaClX of Cartier divisors (which is isomorphic to the Picard group of isomorphism classes of line bundles with tensor product). These groups are isomorphic when X is smooth. In general it is quite difficult to compute these groups. In this section we will give some classic examples without proof.
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