Non-commutative Mori contractions and P 1-bundles

We give a method for constructing maps from a non-commutative scheme to a commutative projective curve. With the aid of Artin-Zhang’s abstract Hilbert schemes, this is used to construct analogues of the extremal contraction of a K-negative curve with self-intersection zero on a smooth projective surface. This result will hopefully be useful in studying… CONTINUE READING