2008/03/20 by Fabrizio Catanese, Catanese, Fabrizio, Marco Franciosi +1 · 1 citation
Mathematics · #14J25 #14J29 #32 Q 30 #Algebraic Geometry (math.AG) #Complex Variables (math.CV) #FOS: Mathematics #math.AG #math.CV #msc:14J25 #msc:14J29 #msc:30 #msc:32
paper · pdf · doi:10.48550/arxiv.0803.3008
12 pages, references added
arxiv created 2008/03/26 · arxiv updated 2009/12/01
We show that the universal cover of a compact complex surface X is the bidisk \HH × \HH, or X is biholomorphic to \PP1 × \PP1, if and only if KX2 > 0 and there exists an invertible sheaf η such that η2≅ \holX and H0(X, S2Ω1X (-KX) ⊗ η) ≠ 0. The two cases are distinguished by the second plurigenus, P2(X)≥ 2 in the former case, P2(X)= 0 in the latter. We also discuss related questions.