实Grassmann流形上的道路空间

Ｇ（ｎ，ｍ）表示Ｒ￣ｎ＋ｍ中全体ｎ维子空间所构成的实Ｇｒａｓｓｍａｎｎ流形。本文首先找到ｐ，ｑ∈Ｇ（ｎ，ｍ）沿任何测地线均不共轭的充要条件，因此连接这样两点的测地线有可数条。通过计算得到编号为（ｋ＿１，ｋ＿２，…，ｋ＿ｎ）的测地线指标λ（ｋ＿１，ｋ＿２…，ｋ＿ｎ）．最后根据Ｍｏｒｓｅ基本定理得到：设ｐ，ｑ是Ｇ（ｎ，ｍ），上沿任何测地线均不共轭的两点，则连接ｐ，ｑ的分段光滑道路空间同伦于一可数ＣＷ－复形，该复形中的胞腔可编号为（ｋ＿１，ｋ＿２，…，ｋ＿ｎ），ｋ＿ｉ为整数，且编号为（ｋ＿１，ｋ＿２，…，ｋ＿ｎ的胞腔的维数为λ（ｋ＿１，ｋ＿２…，ｋ＿ｎ）。     

On the Incidence Geometry of Grassmann Spaces

In this paper we identify some properties on the point-line structure of Grassmannians which are useful tools to characterize the incidence geometry of Grassmann varieties and of their special quotients.     

Cyclic Spaces for Grassmann Derivatives and Additive Theory

Let A be a finite subset of Z_p (where p is a prime). Erdösand Heilbronn conjectured (1964) that the set of sums of the2-subsets of A has cardinality at least min(p, 2|A| —3). We show here that the set of sums of all m-subsets of Ahas cardinality at least min {p,m(|A| — m)+ 1}. In particular,we answer affirmatively the above conjecture. We apply thisresult to the problem of finding the smallest n such that forevery subset 5 of cardinality n and every xZ_p there is a subsetof S with sum equal to x. On this last problem we improve theknown results due to Erdös and Heilbronn and to Olson. The above result will be derived from the following generalproblem on Grassmann spaces. Let F be a field and let V be afinite dimensional vector space of dimension d over F. Let pbe the characteristic of F in nonzero characteristic and otherwise. Let Df be the derivative of a linear operatorfon V, restrictedto the mth Grassmann space ^mV. We show that there is a cyclicsubspace for the derivative with dimension at least min {p,m(n–m)+ 1}, where n is the maximum dimension of the cyclic subspacesof f. This bound is sharp and is reached when f has d distincteigenvalues forming an arithmetic progression.     

Holomorphic maps into Grassmann manifolds (harmonic maps into Grassmann manifolds III)

Annals of Global Analysis and Geometry - A well-known Calabi’s rigidity theorem on holomorphic isometric immersions into the complex projective space is generalized to the case that the...     

Nonlinear Transformations of Smooth Measures on Infinite-Dimensional Spaces

We investigate the properties of the image of a differentiable measure on an infinitely-dimensional Banach space under nonlinear transformations of the space. We prove a general result concerning the absolute continuity of this image with respect to the initial measure and obtain a formula for density similar to the Ramer–Kusuoka formula for the transformations of the Gaussian measure. We prove the absolute continuity of the image for classes of transformations that possess additional structural properties, namely, for adapted and monotone transformations, as well as for transformations generated by a differential flow. The latter are used for the realization of the method of characteristics for the solution of infinite-dimensional first-order partial differential equations and linear equations with an extended stochastic integral with respect to the given measure.     

平移空间的线性结构

本文证明了在平移空间上可利用距离在一定条件下构作出线性结构,引入了次范整线性空间的概念,还证明了平移空间是次范整线性空间当且仅当它的平移群是Abel群.泛函分析学中的有界线性算子定理,Hahn-Banach定理以及共鸣定理都可以移植于次范整线性空间之中.     

点传递线性空间

本文是关于点传递线性空间的一个分类工作. 设${\mathcal{S}}$是一个点数为51的正则线性空间,其线长为6, $G$ 是${\cal S}$的一个自同构群.本文证明了群$G$不可能点传递.     

线性变换的GM元对

In this short note we discuss the GM property of some special linear transformation pairs over infinite-dimensional vector spaces. In particular, it is proved that if R = End(VD)is the endomorphism ring of an infinite-dimensional right vector space V over a division ring D with |C(D)| 3 and g ∈ R, then(a0+ a1g, g) is a GM pair for any a0, a1∈ C(D).Furthermore, two existing results are obtained as immediate consequences.     

On Linear Transformations of Intersections

Set-Valued and Variational Analysis - For any linear transformation and two convex closed sets, we provide necessary and sufficient conditions for the transformation of the intersection of the sets...     

赋范线性空间上有界线性泛函的一般形式

1968年,N.E.Gretsky求得了Banach函数空间上有界线性泛函的一般形式。1977年,G.D.Faulkner对自反的Banach空间解决了这个问题。又本文作者对一类无限多个Banach空间解决了有界线性泛函的表示问题。 本文对一般的赋范线性空间给出了有界线性泛函的表达式和共轭空间的等距同构表现。     

Matrix Transformations Between Some Vector-Valued Sequence Spaces

In this paper, we give necessary and sufficient conditions for infinite matrices mapping from the Nakano vector-valued sequence space (X, p) into any BK-space, and by using this result, we obtain the matrix characterizations from (X, p) into the sequence spaces (Y), c₀(Y, q), c(Y), _s(Y), E_r(Y), and F_r(Y), where p = (p_k) and q = (q_k) are bounded sequences of positive real numbers such that p_k 1 for all k N, r 0, and s 1.AMS Subject Classification (2000): 46A45     

On the Functions on Linear Spaces

In this paper are considered the authors results that have been received in the last few years and are devoted to the research of functions mapping a finite linear space to itself. The characteristics of functions representing interest from the point of view of cryptography, geometrical properties of functions are resulted. This research is supported by RFFI (grants 99-01-00929 and 99-01-00941).Mathematics Subject Classifications (2000) 51E15, 51E20.