A Threefold with pg=0p_g=0 and P2=2P_2=2

  • Ezio Stagnaro

    Università di Padova, Italy

Abstract

We construct a nonsingular threefold X with _q_1 = _q_2 = p__g = 0 and _P_2 = 2 whose m-canonical transformation φ|m__KX| has the following properties
i) φ|m__KX| has the generic fiber of dimension ≥ 1, for 2 ≤ m ≤ 5;
ii) it is generically a tranformation 2 : 1, for 6 ≤ m ≤ 8 and m = 10;
iii) it is birational for m = 9 and m ≥ 11.

Cite this article

Ezio Stagnaro, A Threefold with pg=0p_g=0 and P2=2P_2=2. Rend. Sem. Mat. Univ. Padova 121 (2009), pp. 13–31

DOI 10.4171/RSMUP/121-2