拓扑遍历与拓扑双重遍历

令X为紧致度量空间,f:X→X为连续映射,U,V为X的任意非空开集,若{n>0|fn(U)∩V≠ )为正上密度集,则称f拓扑遍历.f拓扑双重遍历意味着f×f拓扑遍历.本文在[2]的基础上进一步讨论拓扑遍历与拓扑双重遍历映射的性质.     

模糊拓扑空间的最小Hausdorff拓扑

本文利用模糊滤子的ｍ－收敛概念对模糊拓扑空间的最小Ｈａｕｓｄｏｒｆｆ拓扑的特征进行了刻画，对模糊网的ｍ－收敛与模糊拓扑空间的ｍ－紧之间的关系以及最小Ｈａｕｓｄｏｒｆｆ拓扑与ｍ－紧之间的关系进行了研究。     

模糊化弱拓扑和模糊化预拓扑

在模糊化拓扑空间基础上,放宽了模糊化拓扑结构的公理体系,引入模糊化弱拓扑和模糊化预拓扑的概念,并且讨论了它们构成的范畴和模糊化拓扑空间范畴的关系.结果表明,模糊化拓扑空间范畴既是模糊化弱拓扑空间范畴的双余反射满子范畴,又是模糊化预拓扑空间范畴的双余反射满子范畴.     

拓扑剩余格

利用剩余格L中滤子系统F={F_i:i∈Λ}诱导的拓扑τ_F,证明了(L,τ_F)是拓扑剩余格,给出拓扑剩余格(L,τ_F)中任意一个非空集合的闭包的表达形式,并且在给定的一些特殊的条件下证明了(L,τ_F)是Hausdorff空间.     

最强Orlicz-Pettis拓扑

引进了lp（p≥1）空间的子集是本性紧概念,借此给出了抽象对偶系统（E,F）中最强Orlicz－Petits拓扑SOP（E,F）以及产生该拓扑的最大映射集族的表示．利用此结果搞清楚了现有两种Orlicz－Petits拓扑即Dierolf拓扑（M）和Twed－dle拓扑（E,T’）的确切意义以及它们之间的相互关系．指出了的最大性所蕴涵的理论意义和应用价值．证实了σ（F,E）-条件紧集和σ（F,E）-可数紧集都含于中。进而实质性地改进了矢位测度论中的Graves－Rness定理、抽象函数论中的Thomas定理等重要结果．     

A-拓扑以及A-拓扑空间的相关性质

设E是一个A rch im edean R iesz空间,a∈E,Φ≠A E,则有如下的两个结论:1)由a生成的a-拓扑空间E是一个H ausdorff空间;2)若以下条件之一成立,则由A生成的A-拓扑空间E是一个H ausdorff空间:(a)子集{a:a∈A}有上界;(b)E具有强单位元;(c)若E=C(X),其中X是一个局部紧H ausdorff空间.     

半拓扑系统

本文旨在建立Ｓ系统理论，它具有相当的广泛性，以及应用背景性，同时又以拓扑空间、模糊拓扑空间、拓扑分子格以及拓扑系统为特例．     

φ-拓扑

§1 φ-函子在连续格理论中存在着一类具有共性的函子,如函子φ_s:范畴COM_s(对象完备格,态射保任意交)→集范畴SET,φ_(L)为L的全体单点集;φ_D:范畴COM_D(对象为完备格,态射保任意交、有向并)→SET,φ_D(L)为L的全体有向集;φ_c:范畴COM_c(对象为完备格,态射保任意交、并)→SET,φ_c(L)为L的幂集P(L)。诸如此类的函子,我们给出定义如下:     

半粘合拓扑空间与商半拓扑空间

作者在文［１］中给出了半粘合拓扑空间以及半粘合映射的定义，并得到了它们的基本性质。中文进一步研究了与半枯合拓扑空间和半粘合映射有关的问题。另外也讨论了商空间成为Ｓ_２－拓扑空间的条件．最后给出了一个半同胚定理。     

完备格上的上拓扑和区间拓扑

对完备格 Ｌ;记ｖ（Ｌ）为 Ｌ上的上拓扑之闭集格本文证明了完备格 Ｌ为 Ｆ－分配格当且仅当映射ｓｕｐ：ｖ（Ｌ）→Ｌ为满完备格同态;若Ｌ为Ｆ－分配的Ｂｏｏｌｅ格,则Ｌ同构于某幂集格、对Ｔ１格 Ｌ,证明了下述各条件等价。（１） Ｌ同构于某幂集格;（２） Ｌ上的区间拓扑是 Ｈａｕｓｄｏｒｆｆ的;（３）是有限分离的;（４） Ｌ是连续的对马空间（Ｘ,Ｏ（Ｘ））,进一步证明了 Ｏ（Ｘ）上的区间拓扑不可能为 Ｈａｕｓｄｏｒｆｆ的,除非（Ｘ, Ｏ（Ｘ））是离散空间．     

Quasicontinuity of Posets via Scott Topology and Sobrification

In this paper, posets which may not be dcpos are considered. In terms of the Scott topology on posets, the new concept of quasicontinuous posets is introduced. Some properties and characterizations of quasicontinuous posets are examined. The main results are: (1) a poset is quasicontinuous iff the lattice of all Scott open sets is a hypercontinuous lattice; (2) the directed completions of quasicontinuous posets are quasicontinuous domains; (3) A poset is continuous iff it is quasicontinuous and meet continuous, generalizing the relevant result for dcpos. Supported by the NSF of China (10371106, 10410638) and by the Fund (S0667-082) from Nanjing University of Aeronautics and Astronautics.     

Order topology and bi-Scott topology on a poset

In this paper, some properties of order topology and bi-Scott topology on a poset are obtained. Order-convergence in posets is further studied. Especially, a sufficient and necessary condition for order-convergence to be topological is given for some kind of posets.     

关于连续偏序集的一个刻画定理(英文)

本文给出了连续偏序集的一个刻画定理及相应的代数偏序集刻画定理.进一步得出连续偏序集P关于其Scott拓扑是局部紧的,而且OFilt(P)是一个domain.这推广了关于dcpo的对应结果.     

Strongly continuous posets and the local Scott topology

In this paper, the concept of strongly continuous posets (SC-posets, for short) is introduced. A new intrinsic topology—the local Scott topology is defined and used to characterize SC-posets and weak monotone convergence spaces. Four notions of continuity on posets are compared in detail and some subtle counterexamples are constructed. Main results are: (1) A poset is an SC-poset iff its local Scott topology is equal to its Scott topology and is completely distributive iff it is a continuous precup; (2) For precups, PI-continuity, LC-continuity, SC-continuity and the usual continuity are equal, whereas they are mutually different for general posets; (3) A T₀-space is an SC-poset equipped with the Scott topology iff the space is a weak monotone convergence space with a completely distributive topology contained in the local Scott topology of the specialization order.     

Topology of Hom complexes and test graphs for bounding chromatic number

The Hom complex of homomorphisms between two graphs was originally introduced to provide topological lower bounds on the chromatic number. In this paper we introduce new methods for understanding the topology of Hom complexes, mostly in the context of Γ-actions on graphs and posets (for some group Γ). We view the Hom(T, ⊙) and Hom(⊙, G) complexes as functors from graphs to posets, and introduce a functor (⊙)¹ from posets to graphs obtained by taking atoms as vertices. Our main structural results establish useful interpretations of the equivariant homotopy type of Hom complexes in terms of spaces of equivariant poset maps and Γ-twisted products of spaces. When P:= F(X) is the face poset of a simplicial complex X, this provides a useful way to control the topology of Hom complexes. These constructions generalize those of the second author from [17] as well as the calculation of the homotopy groups of Hom complexes from [8].     

Prime, irreducible elements and coatoms in posets

In this paper, some properties of prime elements, pseudoprime elements, irreducible elements and coatoms in posets are investigated. We show that the four kinds of elements are equivalent to each other in finite Boolean posets. Furthermore, we demonstrate that every element of a finite Boolean poset can be represented by one kind of them. The example presented in this paper indicates that this result may not hold in every finite poset, but all the irreducible elements are proved to be contained in each order generating set. Finally, the multiplicative auxiliary relation on posets and the notion of arithmetic poset are introduced, and some properties about them are generalized to posets.     

Continuity of posets via Scott topology and sobrification

In this paper, posets which may not be dcpos are considered. The concept of embedded bases for posets is introduced. Characterizations of continuity of posets in terms of embedded bases and Scott topology are given. The main results are:

(1)

A poset is continuous iff it is an embedded basis for a dcpo up to an isomorphism;

(2)

A poset is continuous iff its Scott topology is completely distributive;

(3)

A topological T₀ space is a continuous poset equipped with the Scott topology in the specialization order iff its topology is completely distributive and coarser than or equal to the Scott topology;

(4)

A topological T₁ space is a discrete space iff its topology is completely distributive.

These results generalize the relevant results obtained by J.D. Lawson for dcpos.     

关于Scott开滤子拓扑的core紧性

本文讨论了那样一些ＤＣＰＯ（即定向完备偏序集）的刻划问题,它们在赋以Ｓｃｏｔｔ开滤子拓扑后,其拓扑空间的开集格是连续格。该问题也是由ＬａｗｓｏｎＪＤ。与ＭｉｓｌｏｖｅＭ．提出的一系列公开问题中的一个［１］。     

连续偏序集及其Smyth幂的几个等权定理

推广连续D om a in的权的概念到连续偏序集上,探讨连续偏序集的权、相应内蕴拓扑的权、定向完备化的权以及Sm yth幂D om a in的权间的关系。得到了几个等权定理:(1)连续偏序集的权与其上Scott拓扑、L aw son拓扑的权相等;(2)连续偏序集的权与其定向完备化的权相等;(3)无穷连续D om a in的权与其Sm yth幂D om a in的权相等;(4)有限D om a in的权小于或等于它的Sm yth幂D om a in的权。