搜索结果: 1-15 共查到“理学 coverings”相关记录18条 . 查询时间(0.088 秒)
Collapsing and essential coverings
the Gromov-Hausdorff convergence Alexandrov spaces Betti numbers
2012/5/25
In the present paper, we consider the family of all compact Alexandrov spaces with curvature bound below having a definite upper diameter bound of a fixed dimension. We introduce the notion of essenti...
A new fuzzy rough sets based on fuzzy coverings
Rough set Fuzzy covering Fuzzy covering information system Homomorphism Attribute reduction
2012/4/17
This paper provides further study on fuzzy coverings based rough sets. We first present the notions of the lower and upper approximation operators based on fuzzy coverings and derive their basic prope...
Bergman Type Metrics in Tower of Coverings
Bergman Type Metrics Tower of Coverings Algebraic Geometry
2011/9/22
Abstract: We establish a version of a statement attributed to Kazhdan by Yau. As a corollary, we obtain a more transparent form of our uniformization theorem in complex algebraic geometry.
Coverings over Tori and Topological Approach to Klein's Resolvent Problem
Tori and Topological Klein's Resolvent Problem Algebraic Geometry
2011/9/14
Abstract: This work answers the question what coverings over a topological torus can be induced from a covering over a space of dimension $k$. The answer to this question is then applied in algebro-ge...
Galois and universal universal coverings of linear categories and fibre products
fibre product section Galois covering universal covering
2011/2/21
Let k be a commutative ring. We study the behaviour of coverings of k-categories through fibre products and find a criterion for a covering to be Galois or universal.
Cyclic branched coverings of knots and quandle homology
quandle homology group homology cyclic branched covering
2011/2/22
We give a construction of quandle cocycles from group cocycles,especially quandle cocycles of the dihedral quandle Rp from group cocycles of the cyclic group Z/p.
Exponential growth of torsion in Abelian coverings
Exponential growth of torsion Abelian coverings
2011/2/22
We show exponential growth of torsion numbers for links whose first nonzero Alexander polynomial has positive logarithmic Mahler measure. This extends a theorem of Silver ndWilliams
to the case of a ...
Green functions, the fine topology and restoring coverings
Harmonic measure Jensen measures Subharmonic functions
2011/2/22
There are several equivalent ways to define continuous harmonic functions H(K) on a compact set K in Rn. One may let H(K) be the unform closures of all functions in C(K) which are restrictions of harm...
Normal coverings of finite symmetric and alternating groups
Normal coverings alternating groups
2010/11/23
In this paper we investigate the minimum number of maximal subgroups H_i for i=1 ...k of the symmetric group S_n (or the alternating group A_n) such that each element in the group S_n (respectively A...
Generalized covering designs and clique coverings
Generalized covering designs clique coverings
2010/11/22
Inspired by the "generalized t-designs" defined by Cameron [P. J. Cameron, A generalisation of t-designs, Discrete Math. 309 (2009), 4835--4842], we define a new class of combinatorial designs which ...
Geometrization of postcritically finite branched coverings
Geometrization postcritically finite branched coverings
2010/11/15
We study canonical decompositions of postcritically finite branched coverings of the 2-sphere, as defined by K.~Pilgrim. We show that every hyperbolic cycle in the decomposition does not have a Thurst...
On a question by Corson about point-finite coverings
coverings of Banach spaces point- nite coverings tilings
2010/12/10
We answer in the armative the following question raised by H. H. Corson in 1961: " Is it possible to cover every Banach space X by bounded convex sets with nonempty interior in such a way that no poi...
Matchings, coverings, and Castelnuovo-Mumford regularity
Matchings coverings Castelnuovo-Mumford regularity
2010/12/6
We show how co-chordal covers of the edges of a graph give upper bounds on the Castelnuovo-Mumford regularity of its edge ideal. The proof is by an easy application of a deep result of
Kalai and Mesh...
Coverings of the Symmetric and Alternating Groups
Coverings of the Symmetric Alternating Groups
2010/12/9
We analyse for which n there exist in G = An, Sn two proper subgroups H,K such that G is the union of the G-conjugacy classes of H and K.
In this paper we study a notion of a -covering in connection with Bernstein sets and other types of nonmeasurability. Our results correspond to those obtained by Muthuvel in [7] and Nowik in [8]. We ...