共查询到20条相似文献,搜索用时 15 毫秒
1.
Norman L. Johnson Giuseppe Marino Olga Polverino Rocco Trombetti 《Finite Fields and Their Applications》2008,14(2):456-469
In [G. Marino, O. Polverino, R. Trombetti, On -linear sets of PG(3,q3) and semifields, J. Combin. Theory Ser. A 114 (5) (2007) 769–788] it has been proven that there exist six non-isotopic families (i=0,…,5) of semifields of order q6 with left nucleus and center , according to the different geometric configurations of the associated -linear sets. In this paper we first prove that any semifield of order q6 with left nucleus , right and middle nuclei and center is isotopic to a cyclic semifield. Then, we focus on the family by proving that it can be partitioned into three further non-isotopic families: , , and we show that any semifield of order q6 with left nucleus , right and middle nuclei and center belongs to the family . 相似文献
2.
Ju Myung Kim 《Journal of Mathematical Analysis and Applications》2006,320(2):619-631
This paper is concerned with compactness for some topologies on the collection of bounded linear operators on Banach spaces. New versions of the Eberlein–Šmulian theorem and Day's lemma in the collection are established. Also we obtain a partial solution of the dual problem for the quasi approximation property, that is, it is shown that for a Banach space X if X** is separable and X* has the quasi approximation property, then X has the quasi approximation property. 相似文献
3.
Dalibor Volný Benjamin Weiss 《Annales de l'Institut Henri Poincaré (B) Probabilités et Statistiques》2004,40(6):771-778
Let T be an ergodic automorphism of a probability space, f a bounded measurable function, . It is shown that the property that the probabilities μ(|Sn(f)|>n) are of order n−p roughly corresponds to the existence of an approximation in L∞ of f by functions (coboundaries) g−g○T, gLp. Similarly, the probabilities μ(|Sn(f)|>n) are exponentially small iff f can be approximated by coboundaries g−g○T where g have finite exponential moments.
Résumé
Soit T un automorphisme ergodique d'un espace probabilisé, f une fonction bornée mesurable et . Une correspondance est établie entre l'existence de l'estimation des probabilités μ(|Sn(f)|>n) d'ordre n−p et l'existence de l'approximation dans L∞ de la fonction f par des cobords g−g○T où g est “presque” dans Lp. De manière similaire, les probabilités μ(|Sn(f)|>n) sont d'ordre e−cn, pour un certain c>0, n=1,2… , si et seulement si f admet une approximation dans L∞ par des cobords g−g○T avec g ayant des moments exponentiels. 相似文献4.
5.
Classification of Lorentzian surfaces with parallel mean curvature vector in pseudo-Euclidean spaces
Spatial surfaces with parallel mean curvature vector in pseudo-Euclidean spaces of arbitrary dimension and index were classified by B.Y. Chen. In this work, we give a complete classification of Lorentzian surfaces with parallel mean curvature vector in pseudo-Euclidean spaces of arbitrary dimension and index. Consequently, the problem to classify all the surfaces with parallel mean curvature vector in pseudo-Euclidean spaces has been solved. 相似文献
6.
The extension field where q is a prime divisor of (P−1), has a unique structure. This paper describes this unique structure and uses it to derive formulas relating the trace values for elements in . These formulas can be refined for certain elements to produce a formula for the trace. 相似文献
7.
The solution of the linear operator equation:An-1X+An-2XB++AXBn-2+XBn-1=Y is given by if the spectra of A and B are in the sector {z:z≠0,-π/n<argz<π/n}. 相似文献
8.
Ai-Guo Wu Hao-Qian Wang Guang-Ren Duan 《Journal of Computational and Applied Mathematics》2009,230(2):690-698
With the help of the concept of Kronecker map, an explicit solution for the matrix equation X−AXF=C is established. This solution is neatly expressed by a symmetric operator matrix, a controllability matrix and an observability matrix. In addition, the matrix equation is also studied. An explicit solution for this matrix equation is also proposed by means of the real representation of a complex matrix. This solution is neatly expressed by a symmetric operator matrix, two controllability matrices and two observability matrices. 相似文献
9.
In this paper we will treat a generalization of inner and outer approximations of fuzzy sets, which we will call -inner and -outer approximations respectively ( being any finite set of rational numbers in [0,1]). In particular we will discuss the case of those fuzzy sets which are definable in the logic by means of step functions from the hypercube [0,1]k and taking value in an arbitrary (finite) subset of . Then, we will show that if a fuzzy set is definable as truth table of a formula of , then both its -inner and -outer approximation are definable as truth table of formulas of . Finally, we will introduce a generalization of abstract approximation spaces and compare our approach with the notion of fuzzy rough set. 相似文献
10.
Let k be an algebraically closed field of characteristic 2. We prove that the restricted nilpotent commuting variety , that is the set of pairs of (n×n)-matrices (A,B) such that A2=B2=[A,B]=0, is equidimensional. can be identified with the ‘variety of n-dimensional modules’ for , or equivalently, for k[X,Y]/(X2,Y2). On the other hand, we provide an example showing that the restricted nilpotent commuting variety is not equidimensional for fields of characteristic >2. We also prove that if e2=0 then the set of elements of the centralizer of e whose square is zero is equidimensional. Finally, we express each irreducible component of as a direct sum of indecomposable components of varieties of -modules. 相似文献
11.
For all integers m3 and all natural numbers a1,a2,…,am−1, let n=R(a1,a2,…,am−1) represent the least integer such that for every 2-coloring of the set {1,2,…,n} there exists a monochromatic solution to
a1x1+a2x2++am−1xm−1=xm.