ON SINGULARITIES OF MIP 3(c1, c2)
نویسنده
چکیده
Let MIP 3(c1, c2) be the moduli space of stable rank-2 vector bundles on IP 3 with Chern classes c1, c2. We prove the following results. 1) Let 0 ≤ β < γ be two integers, (γ ≥ 2), such that 2γ− 3β > 0; then MIP 3(0, 2γ 2 − 3β) is singular (the case β = 0 was previously proved by M. Maggesi). 2) Let 0 ≤ β < γ be two odd integers (γ ≥ 5), such that 2γ − 3β + 1 > 0; then MIP 3(−1, 2(γ/2) 2 − 3(β/2) + 1/4) is singular. In particular MIP 3(0, 5), MIP 3(−1, 6) are singular.
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