共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
3.
4.
Let be the -dimensional complex projective space, and let be two non-empty open subsets of in the Zariski topology. A hypersurface in induces a bipartite graph as follows: the partite sets of are and , and the edge set is defined by if and only if . Motivated by the Turán problem for bipartite graphs, we say that is -grid-free provided that contains no complete bipartite subgraph that has vertices in and vertices in . We conjecture that every -grid-free hypersurface is equivalent, in a suitable sense, to a hypersurface whose degree in is bounded by a constant , and we discuss possible notions of the equivalence.We establish the result that if is -grid-free, then there exists of degree in such that . Finally, we transfer the result to algebraically closed fields of large characteristic. 相似文献
5.
Moulay Taïb Belghiti Boutayeb El Ammari Laurent P. Gendre 《Comptes Rendus Mathematique》2018,356(11-12):1125-1130
We study the problem of global approximation by polynomials in Whitney -flat jet classes on irregular compacts of . 相似文献
6.
7.
8.
Indranil Biswas Subramaniam Senthamarai Kannan Donihakalu Shankar Nagaraj 《Comptes Rendus Mathematique》2017,355(4):452-454
Let be the wonderful compactification of a simple affine algebraic group G of adjoint type defined over . Let be the closure of a maximal torus . We prove that the group of all automorphisms of the variety is the semi-direct product , where is the normalizer of T in G and D is the group of all automorphisms of the Dynkin diagram, if . Note that if , then and so in this case . 相似文献
9.
10.
11.
Leonardo Meireles Câmara 《Indagationes Mathematicae》2018,29(3):878-884
In this paper we show that a transversely holomorphic foliation in a compact manifold having an infinite number of invariant hypersurfaces admits a basic transversely meromorphic first integral . 相似文献
12.
Filippo Bracci Manuel D. Contreras Santiago Díaz-Madrigal 《Journal de Mathématiques Pures et Appliquées》2017,107(1):78-99
Let , be two one-parameter semigroups of holomorphic self-maps of the unit disk . Let be a homeomorphism. We prove that, if for all , then f extends to a homeomorphism of outside exceptional maximal contact arcs (in particular, for elliptic semigroups, f extends to a homeomorphism of ). Using this result, we study topological invariants for one-parameter semigroups of holomorphic self-maps of the unit disk. 相似文献
13.
In this work we analyze some topological properties of the remainder of the semialgebraic Stone–Cěch compactification of a semialgebraic set in order to ‘distinguish’ its points from those of M. To that end we prove that the set of points of that admit a metrizable neighborhood in equals where is the largest locally compact dense subset of M and is the closure in M of the set of 1-dimensional points of M. In addition, we analyze the properties of the sets and of free maximal ideals associated with formal and semialgebraic paths. We prove that both are dense subsets of the remainder ?M and that the differences and are also dense subsets of ?M. It holds moreover that all the points of have countable systems of neighborhoods in . 相似文献
14.
15.
16.
18.
19.