图象拓扑下的Ky Fan引理解集的本质连通区及其在对策论上的应用

本文在集值映射的图象拓扑意义下,证明了赋范线性空间中的Ky Fan引理的解集的本质连通区的存在性,由此得到一类对策的Nash平衡点集的本质连通区的存在性.     

Effective Borel degrees of some topological functions

The focus of this paper is the incomputability of some topological functions (with respect to certain representations) using the tools of Borel computability theory, as introduced by V. Brattka in [3] and [4]. First, we analyze some basic topological functions on closed subsets of ?ⁿ , like closure, border, intersection, and derivative, and we prove for such functions results of Σ⁰₂‐completeness and Σ⁰₃‐completeness in the effective Borel hierarchy. Then, following [13], we re‐consider two well‐known topological results: the lemmas of Urysohn and Urysohn‐Tietze for generic metric spaces (for the latter we refer to the proof given by Dieudonné). Both lemmas define Σ⁰₂‐computable functions which in some cases are even Σ⁰₂‐complete. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Necessary and Sufficient Conditions for Solving Infinite-Dimensional Linear Inequalities

The existence of a feasible solution to a system of infinite-dimensional linear inequalities is characterized by a topological generalization of the Farkas Condition. If this result is specialized to a finite-dimensional vector space with finite positive cone, then a geometric proof of the classic Minkowski-Farkas Lemma is obtained. A dual version leads to an infinite-dimensional extension of the Theorem of the Alternative.     

On Iterations of the Green Integrals and their Applications to Elliptic Differential Complexes

Convergence of iterations of special Green integrals for overdetermined elliptic linear partial differential operators P of order p ≥ 1 is proved. Using this result we obtain necessary and sufficient conditions for the solvability of the equation Pu = f in the Sobolev space W^p,²(D) and, as a corollary, necessary and sufficient conditions for the vanishing of the first cohomology group of elliptic differential complexes. Also a criterion for the solvability of a P-Neumann problem for elliptic differential operators is proved.     

关于p－拉普拉斯方程径向解的一点注记

本文研究方程ｄｉｖ（｜ｕ｜ｐ－２ｕ）＋｜ｘ｜ｌ｜ｕ｜τ－１ｕ＝０，ｘ∈Ｂ的Ｄｉｒｉｃｈｌｅｔ边值问题ｕ｜Ｂ＝０的径向解。应用山路引理，我们将文［１］的结果（ｐ＝２时）推广到一般情形，证明上述问题有一非平凡的径向解。     

具有无穷维商品空间和不完全金融市场经济的一般均衡存在性(英文）

本文研究具有无穷维商品空间和不完全金融市场两时期经济的一般均衡存在性问题．假设交易发生在证券以币值单位支付的一系列现货市场和期货市场上，并且对证券的卖空没有任何限制．推广的Stiemke引理是情形的基本估值定理，意即证券价格在时间0的现值是时间1状态集合Ω上收益的价值．一般均衡是一列现货价格和期货价格与一列个体计划，使得市场出清．我们证明一般均衡的存在性，条件是经济人具有Mackey连续、弱凸、严格单调和完全的偏好关系与严格正的初始占有．     

Factorization of monic polynomials

We prove a uniqueness result about the factorization of a monic polynomial over a general commutative ring into comaximal factors. We apply this result to address several questions raised by Steve McAdam. These questions, inspired by Hensel's Lemma, concern properties of prime ideals and the factoring of monic polynomials modulo prime ideals.

     

THE HENSTOCK INTEGRAL FOR FUNCTIONS WITH VALUES IN NUCLEAR SPACES AND THE HENSTOCK LEMMA

This paper shows that Henstock‘s Lemma holds for functions with values in a countably Hilbert space, where the Henstock integral is defined as a natural extension of the resl valued case.     

Random partitions and edge-disjoint Hamiltonian cycles

Nash-Williams [1] proved that every graph with n   vertices and minimum degree n/2$n/2$ has at least ⌊5n/224⌋$\lfloor 5n/224\rfloor$ edge-disjoint Hamiltonian cycles. In [2], he raised the question of determining the maximum number of edge-disjoint Hamiltonian cycles, showing an upper bound of ⌊(n+4)/8⌋$\lfloor (n+4)/8\rfloor$.     

New periodic solutions for a class of singular Hamiltonian systems

In this paper, we apply a variant of the famous Mountain Pass Lemmas of Ambrosetti-Rabinowitz and Ambrosetti-Coti Zelati with (PSC)c type condition of Palais-Smale-Cerami to study the existence of new periodic solutions with a prescribed energy for symmetrical singular second order Hamiltonian conservative systems with weak force type potentials.