K3 surfaces and log del Pezzo surfaces of index three
نویسندگان
چکیده
منابع مشابه
The arithmetic of certain del Pezzo surfaces and K3 surfaces
We construct del Pezzo surfaces of degree 4 violating the Hasse principle explained by the Brauer-Manin obstruction. Using these del Pezzo surfaces, we show that there are algebraic families of K3 surfaces violating the Hasse principle explained by the Brauer-Manin obstruction. Various examples are given.
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In this article, a log del Pezzo surface of index two means a projective normal non-Gorenstein surface S such that (S, 0) is a log-terminal pair, the anti-canonical divisor −KS is ample and that 2KS is Cartier. The log del Pezzo surfaces of index two are shown to be constructed from data (X,E,∆) called fundamental triplets consisting of a non-singular rational surface X, a simple normal crossin...
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, or there are 22 possibilities for (a0, a1, a2, a3) found in [28]. It follows from [12], [28], [4], [1] that the inequality lct(X) > 2/3 holds in the case when X is singular and general. Example 1.4. Let X be a quasismooth hypersurface in P(a0, . . . , a4) of degree ∑4 i=0 ai − 1, where a0 6 a1 6 a2 6 a3 6 a4. Then lct(X) > 3/4 for 1936 values of (a0, a1, a2, a3, a4) (see [29]). Example 1.5. L...
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0.1 Throughout this paper, a del Pezzo surface is by definition a connected, 2-dimensional, projective k-scheme X,OX(1) that is Gorenstein and anticanonically polarised; in other words, X is Cohen–Macaulay, and the dualising sheaf is invertible and antiample: ωX ∼= OX(−1). For example, X = X3 ⊂ P 3 an arbitrary hypersurface of degree 3. Under extra conditions, del Pezzo surfaces are interesting...
متن کاملOn the Combinatorial Classification of Toric Log Del Pezzo Surfaces
Toric log del Pezzo surfaces correspond to convex lattice polygons containing the origin in their interior and having only primitive vertices. An upper bound on the volume and on the number of boundary lattice points of these polygons is derived in terms of the index l. Techniques for classifying these polygons are also described: a direct classification for index two is given, and a classifica...
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ژورنال
عنوان ژورنال: Manuscripta Mathematica
سال: 2012
ISSN: 0025-2611,1432-1785
DOI: 10.1007/s00229-011-0524-z