非紧H-空间中的极大元存在定理及其应用

本文在一类非紧Ｈ－空间中建立了新的极大元存在定理。作为应用,我们研究了变分不等式和ＫｙＦａｎ型极大极小不等式解的存在性。     

A New Existence Theorem of Maximal Elements in Non-Compact H-Spaces with Applications to Minimax Inequalities and Variational Inequalities

We give a new existence theorem of maximal elements in non-compact H-spaces. As applications, two extended versions of Fan-Yen minimax inequality are obtained and the existence problems of solutions of variational inequalities and quasi-variational inequalities are studied.     

不完备偏好扩展式博弈的序贯均衡

将Kreps和Wilson提出的序贯均衡解概念推广到了存在不完备偏好的情形.首先给出了一个修正的颤抖手完美均衡的概念,然后应用它去证明不完备偏好扩展式博弈序贯均衡的存在性.     

乘积G—凸空间内的GB—优化映象的极大元及其应用（1）

引入和研究了一类新的映拓扑空间到不同广义凸空间的集值映象簇.利用连续单位分解定理和Brouwer不动点定理,在乘积广义凸空间的非紧设置下,对这类集值映象簇证明了极大元存在定理.这些定理改进,统一和推广了近期文献中许多重要结果.     

乘积G-凸空间内的GB-优化映象的极大元及其应用(Ⅰ)

引入和研究了一类新的映拓扑空间到不同广义凸空间的集值映象簇·　利用连续单位分解定理和Brouwer不动点定理,在乘积广义凸空间的非紧设置下,对这类集值映象簇证明了极大元存在定理·　这些定理改进,统一和推广了近期文献中许多重要结果·     

L-凸空间中的新的极大元定理及其对对策平衡的应用

在L-凸空间中建立了新的极大元定理.作为应用,获得了L-凸空间中抽象经济和定性对策的平衡存在定理.     

Finite Groups with 30 Elements of Maximal Order

It is an interesting topic to determine the structure of a finite group which has a given number of elements of maximal order. In this article, the author classified finite groups with 30 elements of maximal order. This work is supported by NSFC (No. 10571128), NSF of CHONGQING (CSTC: 2005BB8096).     

Stochastic Differential Games with Multiple Modes and Applications to Portfolio Optimization

Abstract

We study a zero-sum stochastic differential game with multiple modes. The state of the system is governed by “controlled switching” diffusion processes. Under certain conditions, we show that the value functions of this game are unique viscosity solutions of the appropriate Hamilton–Jacobi–Isaac' system of equations. We apply our results to the analysis of a portfolio optimization problem where the investor is playing against the market and wishes to maximize his terminal utility. We show that the maximum terminal utility functions are unique viscosity solutions of the corresponding Hamilton–Jacobi–Isaac' system of equations.     

广义权函数的最大类逼近及其应用

本文研究了广义权函数的最大类逼近问题,给出了K-最大类和A-最大类的特征刻划．同时也给出了关于广义权函数逼近的唯一性元特征刻划的结果和对某些具体逼近问题的应用,从而推广和改进了他人的结果．     

最大元与经济均衡

首先证明了若偏好对应受Qθ-控制，则最大元一定存在，然后证明了在局部凸拓扑向量空间中若抽象经济（或定性的博弈）中的约束对应或偏好对应受Qθ-控制，则均衡一定存在。     

Optimal Subgroups and Applications to Nilpotent Elements

Let G be a reductive group acting on an affine variety X, let x ∈ X be a point whose G-orbit is not closed, and let S be a G-stable closed subvariety of X which meets the closure of the G-orbit of x but does not contain x. In this paper we study G. R. Kempf’s optimal class Ω _G (x; S) of cocharacters of G attached to the point x; in particular, we consider how this optimality transfers to subgroups of G. Suppose K is a G-completely reducible subgroup of G which fixes x, and let H = C _G (K)⁰. Our main result says that the H-orbit of x is also not closed, and the optimal class Ω _H (x; S) for H simply consists of the cocharacters in Ω _G (x; S) which evaluate in H. We apply this result in the case that G acts on its Lie algebra via the adjoint representation to obtain some new information about cocharacters associated with nilpotent elements in good characteristic.     

乘积 G - 凸空间内的GB - 优化映象的极大元及其应用(Ⅱ)

通过应用G-凸空间的乘积空间内一族GB-优化映象的极大元的存在定理，在G-凸空间的非紧设置下证明了某些重合点定理，Fan-Browder型不动点定理和极小极大不等式组的解的存在性定理．这些定理改进和推广了献中许多重要的已知结果．     

Maximal Regular Abstract Elliptic Equations and Applications

The oblique derivative problem is addressed for an elliptic operator differential equation with variable coefficients in a smooth domain. Several conditions are obtained, guaranteing the maximal regularity, the Fredholm property, and the positivity of this problem in vector-valued L _p-spaces. The principal part of the corresponding differential operator is nonselfadjoint. We show the discreteness of the spectrum and completeness of the root elements of this differential operator. These results are applied to anisotropic elliptic equations.     

FK-映射的匹配定理及其对约束多目标对策的应用

利用 KKM 技巧,建立了FC-空间中转移紧开值FK-映射的Ky Fan匹配定理.作为应用,获得了FC-空间中的Ky Fan重合定理、约束多目标对策的加权 Nash-平衡和Pareto-平衡的存在定理.     

各向异性极大算子及它们的应用

本文证明了一类与异性伸缩相关的极大算子在Ｌ＾ｐ（Ｒ＾ｎ）上是有界的，其中１〈ｐ≤∝，ｎ≥２。进一步，作为应用我们建立了算子Ｔｆ（ｘ）＝ｓｕｐε〉０│Ｔεｆ（ｘ）│Ｌ＾ｐ有界性，其中Ｔε是带有变化核的奇异积分。     

最高阶元素个数为40的非可解群的分类

设$\varphi$为群${\rm Aut}(N)$的同态,记$H_\varphi\times N$为群$N$借助于群$H$的半直积.设$G$为有限不可解群,本文证明: 若$G$中最高阶元素个数为40, 则$G$同构于下列群之一:(1)~$Z_{4\varphi}\times A_5$,\,${\rm ker}\varphi=Z_2$; (2)~$D_{8\varphi}\times A_5,\,{\rm ker}\varphi=Z_2\times Z_2$; (3)~$G/N=S_5$, $N=Z(G)=Z_2$; (4)~$G/N=S_5$, $N=Z_2\times Z_2,\,N\cap Z(G)=Z_2$.     

The Maximal Variation of Martingales of Probabilities and Repeated Games with Incomplete Information

The variation of a martingale $p_{0}^{k}=p_{0},\ldots,p_{k}$ of probabilities on a finite (or countable) set X is denoted $V(p_{0}^{k})$ and defined by $$ V\bigl(p_0^k\bigr)=E\Biggl(\sum_{t=1}^k\|p_t-p_{t-1}\|_1\Biggr). $$ It is shown that $V(p_{0}^{k})\leq\sqrt{2kH(p_{0})}$ , where H(p) is the entropy function H(p)=?∑ _x p(x)logp(x), and log stands for the natural logarithm. Therefore, if d is the number of elements of X, then $V(p_{0}^{k})\leq\sqrt{2k\log d}$ . It is shown that the order of magnitude of the bound $\sqrt{2k\log d}$ is tight for d≤2 ^k : there is C>0 such that for all k and d≤2 ^k , there is a martingale $p_{0}^{k}=p_{0},\ldots,p_{k}$ of probabilities on a set X with d elements, and with variation $V(p_{0}^{k})\geq C\sqrt{2k\log d}$ . An application of the first result to game theory is that the difference between v _k and lim _j v _j , where v _k is the value of the k-stage repeated game with incomplete information on one side with d states, is bounded by $\|G\|\sqrt{2k^{-1}\log d}$ (where ∥G∥ is the maximal absolute value of a stage payoff). Furthermore, it is shown that the order of magnitude of this game theory bound is tight.     

乘积FC-空间内涉及一较好容许集值映象的优化映象族的极大元及其应用

引入了涉及一较好容许集值映象的映一拓扑空间到一有限连续拓扑空间(简称,FC-空间)的优化映象族．在乘积FC-空间的非紧设置下对这类优化映象族证明了某些极大元存在性定理．在乘积FC-空间内给出了对不动点和极小极大不等式组的应用．这些定理改进、统一和推广了最近文献中的很多重要结果．