局部凸H-空间中的Fan—Ha型截口定理及应用

首先在局部凸H-空间中，建立了新Fan—Ha型截口定理及一些相应的等价形式．作为应用，我们在H-空间中研究极大极小定理，本文中的定理把已有文献中的相应结果改进和推广到H-空间．     

集值条件期望的收敛定理

本文给出了集合序列弱极限的表示定理，得到了随机集列关于σ－域流的条件期望序列在弱收敛意义的Fatou型引理和控制收敛定理。     

集-集映射的最优化问题的Lagrange对偶关系

本文讨论集-集映射的多目标最优化问题．首先给出了Lagrange乘子定理，其结果可视作卢占禹(1995)的一个定理在有限维情形时的改进；其次研究了对应的对偶关系，推广了Hsia，W．S．和Lee，T．Y．(1988)文中集-点映射情形时的相应结论．     

1—集压缩映射的主零不动点

本文给出了１－集压缩映射的一些新的非零不动定理，它们推广和改进了［１，２，４，５］中的某些重要定理。     

包络半群与拓扑动力学中的接近关系

运用包络半群的理论，对接近关系中一个重要定理给出了一个简单证明．作为这一定理的应用，我们得到接近关系可乘性的一个结果．并且对另一种接近关系，也得到一个结果．这两个定理减弱了Ｃｌａｙ在这一领域中两个定理的条件．     

关于一个Riemann可积定理的推广

本推广了一个Ｒｉｅｍａｎｎ可积定理，使其条件更为一般。     

第四次数学危机（1）——总述

１９００年，希尔伯特第一问题提出：连续统能否良序？第一个数学家都会说：“它已在１９０４年被Ｚｅｒｍｅｌｏ的良序定理所解决”，本文建立了集合三分法，严格证明了一个良序集一定是一个可数集，同时揭露了良序定理及其它一些定理中证明的错误，因此，现代数学存在着第四次数学危机。     

转移开,闭集值映象和H—KKM定理的推广及应用

本中，我们引入转移开、闭集值映象的概念、推广了Ｈ－空间中的ＫＫＭ定理。然后用所得的结果证明了几个重合定理、匹配定理和向量值极大极小不等式。这些结论推广了近期献〔１，２，４，５，６，７〕中的相应结果。     

偏序集的完备化

首先给出了偏序集的一些完备化的具体构造，又给出了关于完备格中完备子集的某些有用的定理，最终解决了关于偏序集的所有可能的完备化问题     

集值映象的某些重合定理

Browder[1]已得到了Schauder不动点定理的加强形式.许多作者从不同方向推广了Browder的结果.最近H.M.Ko;K.K.Tan[2]在放松紧性条件下得到了Browder定理的改进,K.K.Tan[3]将Browder定理推广到了集值映象对的重合定理,在本文中我们得到了集值映象对的某些重合定理,它们分别改进和推广了[1,2,3]中主要结果.     

Some curious Kleinian groups and hyperbolic 5-manifolds

We present a new family of discrete subgroups ofSO (5, 1) isomorphic to lattices inSO (3, 1). In some of the examples the limit sets are wildly knotted 2-spheres. As an application we produce complete hyperbolic 5-manifolds that are nontrivial plane bundles over closed hyperbolic 3-manifolds and conformally flat 4-manifolds that are nontrivial circle bundles over closed hyperbolic 3-manifolds.     

Classification of Nonorientable 3-Manifolds Admitting Decompositions into ≤ 26 Coloured Tetrahedra

The present paper adopts a computational approach to the study of nonorientable 3-manifolds: in fact, we describe how to create an automaticcatalogue of all nonorientable 3-manifolds admitting coloured triangulationswith a fixed number of tetrahedra. In particular, the catalogue has been effectively produced and analysed for up to 26 tetrahedra, to reach the complete classification of all involved 3-manifolds. As a consequence, the following summarising result can be stated:THEOREM I. Exactly seven closed connected prime nonorientable3-manifolds exist, which admit a coloured triangulation consisting of atmost 26 tetrahedra.More precisely, they are the four Euclidean nonorientable 3-manifolds, the nontrivial S2 bundle overS1, the topological product between thereal projective plane RP2 andS1, and the torus bundle overS1, with monodromy induced by matrix(10 -11).     

Link Homology in 4-Manifolds

We define link homology in 4-manifolds, and show that it hasa close connection to linking numbers and intersection matricesof 4-manifolds. We also define null-homologous links in 4-manifolds.We give a necessary and sufficient condition for links to benull-homologous in 4-manifolds. This condition implies thatfor any 4-manifold with second Betti number n, there are (n+ 2)-component links which are not nullhomologous in the 4-manifold.     

On the Constant Type of Almost Hermitian Manifolds

We suggest a most natural generalization of the notion of constant type for nearly Kählerian manifolds introduced by A. Gray to arbitrary almost Hermitian manifolds. We prove that the class of almost Hermitian manifolds of zero constant type coincides with the class of Hermitian manifolds. We show that the class of G ₁-manifolds of zero constant type coincides with the class of 6-dimensional G ₁-manifolds with a non-integrable structure. Finally, we prove that the class of normal G ₂-manifolds of nonzero constant type coincides with the class of 4-dimensional G ₂-manifolds with a nonintegrable structure.     

Mutation and gauge theory I: Yang-Mills invariants

Mutation of 3-manifolds (cutting and regluing along a genus 2 surface using a central involution) is shown to preserve the instanton Floer homology of homology 3-spheres. A related operation on 4-manifolds is shown to preserve the Donaldson polynomial invariant. Received: November 20, 1998.     

Two-weight estimates for singular and strongly singular integral operators

We give a Pontryagin-Thom type construction for Stein factorizations of fold maps of 3-manifolds into the plane. As an application, we compute the cobordism group of Stein factorizations of fold maps of oriented 3-manifolds into the plane and the oriented cobordism group of fold maps of 3-manifolds into the plane. It turns out that these two groups are isomorphic to Z ₂ ⊕ Z ₂. We have the analogous results about bordism groups as well.      

Asymptotically cylindrical 7-manifolds of holonomy <Emphasis Type="Italic">G</Emphasis><Subscript>2</Subscript> with applications to compact irreducible <Emphasis Type="Italic">G</Emphasis><Subscript>2</Subscript>-manifolds

We construct examples of exponentially asymptotically cylindrical (EAC) Riemannian 7-manifolds with holonomy group equal to G ₂. To our knowledge, these are the first such examples. We also obtain EAC coassociative calibrated submanifolds. Finally, we apply our results to show that one of the compact G ₂-manifolds constructed by Joyce by desingularisation of a flat orbifold T ⁷/Γ can be deformed to give one of the compact G ₂-manifolds obtainable as a generalized connected sum of two EAC SU(3)-manifolds via the method of Kovalev (J Reine Angew Math 565:125–160, 2003).     

Five-Dimensional Contact SU(2)- and SO(3)-Manifolds and Dehn Twists

In the first part of this paper the five-dimensional contact SO(3)-manifolds are classified up to equivariant coorientation preserving contactomorphisms. The construction of such manifolds with singular orbits requires the use of generalized Dehn twists. We show as an application that all simply connected 5-manifolds with singular orbits are realized by a Brieskorn manifold with exponents (k,2,2,2). The standard contact structure on such a manifold gives right-handed Dehn twists, and a second contact structure defined in the article gives left-handed twists. In an appendix we also describe the classification of five-dimensional contact SU(2)-manifolds.     

On the Heegaard genus of contact 3-manifolds

It is well-known that the Heegaard genus is additive under connected sum of 3-manifolds. We show that the Heegaard genus of contact 3-manifolds is not necessarily additive under contact connected sum. We also prove some basic properties of the contact genus (a.k.a. open book genus [Rubinstein J.H., Comparing open book and Heegaard decompositions of 3-manifolds, Turkish J. Math., 2003, 27(1), 189–196]) of 3-manifolds, and compute this invariant for some 3-manifolds.     

Geometric topology of generalized 3-manifolds

In this paper, we describe the history and the present status of one of the main classical problems in low-dimensional geometric topology—the recognition of topological 3-manifolds in the class of all generalized 3-manifolds (i.e., ANR homology 3-manifolds). This problem naturally splits into the cell-like resolution problem for 3-manifolds by means of homology 3-manifolds and the general-position problem for topological 3-manifolds. We have also included some open problems. __________ Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 11, No. 4, pp. 71–84, 2005.