A Threefold with and
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 transformationφ|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 form = 9 and m ≥ 11.
Cite this article
Ezio Stagnaro, A Threefold with and . Rend. Sem. Mat. Univ. Padova 121 (2009), pp. 13–31
DOI 10.4171/RSMUP/121-2