Flips and Variation of Moduli Scheme of Sheaves on a Surface
نویسنده
چکیده
Let H be an ample line bundle on a non-singular projective surface X , and M(H) the coarse moduli scheme of rank-two H-semistable sheaves with fixed Chern classes on X . We show that if H changes and passes through walls to get closer to KX , then M(H) undergoes natural flips with respect to canonical divisors. When X is minimal and κ(X) ≥ 1, this sequence of flips terminates in M(HX); HX is an ample line bundle lying so closely to KX that the canonical divisor of M(HX) is nef. Remark that so-called Thaddeus-type flips somewhat differ from flips with respect to canonical divisors.
منابع مشابه
Flips and Variation of Moduli Schemes of Sheaves on a Surface
Let H be an ample line bundle on a non-singular projective surface X , and M(H) the coarse moduli scheme of rank-two H-semistable sheaves with fixed Chern classes on X . We show that if H changes and passes through walls to get closer to KX , then M(H) undergoes natural flips with respect to canonical divisors, and terminates in M(KX), whose canonical divisor is nef. Remark that so-called Thadd...
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