WebApr 18, 2024 · We show that a del Pezzo fibration π: V → W of degree d contains a vertical open cylinder, that is, an open subset whose intersection with the generic fiber of π is isomorphic to Z × AK1 for some quasi-projective variety Z defined over the function field K of W, if and only if d ≥ 5 and π: V → W admits a rational section. WebCYLINDERS IN WEAK DEL PEZZO FIBRATIONS MASATOMO SAWAHARA Graduate School of Science and Engineering Saitama University Saitama 338-8570, Japan …
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WebMay 6, 2009 · 11 Citations Metrics Abstract We prove that a terminal three-dimensional del Pezzo fibration has no fibers of multiplicity >6. We also obtain a rough classification of possible configurations of singular points on multiple fibers and give some examples. Download to read the full article text References WebDec 18, 2014 · Certainly, cylinders are geometrically simple objects, however they received a lot of attention recently from the viewpoint of unipotent group actions on affine cones over polarized varieties... how much is gorilla tag vr
Cylinders in weak del Pezzo fibrations - NASA/ADS
WebDec 18, 2024 · Cylinders in projective varieties play an important role in connection with unipotent group actions on certain affine algebraic varieties. The previous work due to Dubouloz and Kishimoto deals... WebCYLINDERS IN WEAK DEL PEZZO FIBRATIONS MASATOMO SAWAHARA Abstract. In this article, we shall look into the existence of vertical cylinders contained in a weak del Pezzo fibration as a generalization of the former work due to Dubouloz and Kishimoto in which they observed that of vertical cylinders found in del Pezzo fibrations. The … WebCYLINDERS IN WEAK DEL PEZZO FIBRATIONS 3 (1) Scontains an A1 k-cylinder if and only if d= 8 and Sis endowed with a structure of Mori conic bundle admitting a section defined over k. (2) Scontains the affine plane A2 k if and only if d= 8 and S(k) 6= ∅. Note that Theorem 1.7 excludes the case of Picard rank one since it has already been studied how much is got parasol worth