Curves generating extremal rays in blowups of weighted projective planes
نویسندگان
چکیده
We consider blowups at a general point of weighted projective planes and, more generally, toric surfaces with Picard number one. give unifying construction negative curves on these such that all previously known families appear as boundary cases this. The classification consists two classes said curves, each depending parameters. Every curve in is algebraically related to other both classes; this allows us find their defining equations inductively. For our classification, we family which the defines an extremal class effective cone. complete into Mori Dream Spaces and non-Mori Spaces. Our approach greatly simplifies previous proofs, avoiding positive characteristic methods higher cohomology.
منابع مشابه
An Extremal Characterization of Projective Planes
In this article, we prove that amongst all n by n bipartite graphs of girth at least six, where n = q + q + 1 ≥ 157, the incidence graph of a projective plane of order q, when it exists, has the maximum number of cycles of length eight. This characterizes projective planes as the partial planes with the maximum number of quadrilaterals.
متن کاملOn cubic curves in projective planes of characteristic two
The aim of this paper is to examine various interesting results from the theory of general cub~c curves in projective planes of characteristic two. This leads to calculations involving nets of conics in the plane, invariants of the curves, syzygies, and Hessians. It is emphasized that classical methods, (that is those developed for geometries over fields of zero characteristic), do not always s...
متن کاملHolomorphic curves omitting five planes in projective space
In 1928 H. Cartan proved an extension of Montel’s normality criterion to holomorphic curves in complex projective plane P2. He also conjectured that a similar result is true for holomorphic curves in P for any n. Recently the author constructed a counterexample to this conjecture for any n ≥ 3. In this paper we show how to modify Cartan’s conjecture so that it becomes true, at least for n = 3.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of the London Mathematical Society
سال: 2021
ISSN: ['1469-7750', '0024-6107']
DOI: https://doi.org/10.1112/jlms.12461