拓扑空间范畴、拓扑FUZZ范畴与拓扑分子格范畴间的反射与余反射

从整体角度出发，证明了拓扑空间范畴Ｔｏｐ分别是拓扑Ｆｕｚｚ范畴ＴｏｐＦｕｚ与拓扑分子格范畴ＴＭＬ的反射与余反射满子范畴，ＴｏｐＦｕｚ是ＴＭＬ的反射与余反射（非满）子范畴．     

Irreducible filters and sober spaces

A filterF on a convergence space is called irreducible, iff the set convF of convergence points ofF belongs toF. A space is sober, iff for every irreducible filterF there is a unique point x with convF=conv x. The categorySob-Conv of sober convergence spaces is a full productive, but not a reflective subcategory of the categoryConv of convergence spaces and continuous maps. For a topological space (X,t) the following are equivalent: (i) for every irreducible filterF on (X,t) there is a point x withF=x (ii) (X,t) is both sober and T_D (iii) every subspace of (X,t) is sober (iv) every topological space finer than (X,t) is sober (v) whenever (Y,s) is a T_o-space whose latticeO(Y,s) of open sets is isomorphic toO(x,t), then (Y,s)(X,t). The categorySob-T ₁ß of sober T₁-spaces is the greatest epi-reflective subcategory ofTop consisting of sober spaces, moreoverSob-T ₁ß is a dis-connectedness in the sense of Preuß- Arhangelskii-Wiegandt (generated by all irreducible spaces), henceSob-T ₁ is (extremal epi)-reflective inTop. It is strictly between T₁ and T₂ and different from various sorts of weak Hausdorffness discussed in the literature.     

Limit分子格

通过在完全分配格上引入理想收敛,给出ｌｉｍｉｔ分子格及其范畴,证明了其是包含拓扑分子格范畴为全反射范畴的笛卡儿闭范畴．     

L-模糊化拓扑空间中的Moore-Smith收敛理论

This paper presents a definition of L-fuzzifying nets and the related L-fuzzifying generalized convergence spaces. The Moore-Smith convergence is established in L-fuzzifying topology. It is shown that the category of L-fuzzifying generalized convergence spaces is a cartesianclosed topological category which embeds the category of L-fuzzifying topological spaces as a reflective subcategory.     

On the Reflectivity and Coreflectivity of L-Fuzzifying Topological Spaces in L-Topological Spaces

In this paper it is proved that for all completely distributive lattices L, the category of L-fuzzifying topological spaces can be embedded in the category of L-topological spaces (stratified Chang-Goguen spaces) as a simultaneously bireflective and bicoreflective full subcategory. Received April 2, 1999, Revised January 31, 2000, Accepted February 2, 2000     

Approach Spaces, Limit Tower Spaces, and Probabilistic Convergence Spaces

The category LTS of limit tower spaces is defined and shown to be isomorphic to the category CAP of convergence approach spaces. The full subcategory of LTS determined by the objects satisfying a diagonal axiom due to Cook and Fischer is shown to be isomorphic to the category AP of approach spaces. A family of isomorphisms is also obtained between LTS and certain full subcategories of the category PCS of probabilistic convergence spaces.     

On the category of lattice-valued bornological vector spaces

Motivated by the theory of L-bornological spaces of M. Abel and A. Šostak over a complete lattice L, and the concept of topological system of S. Vickers, this paper introduces the categories of L-bornological vector spaces and systems, and shows that the former is isomorphic to a full reflective subcategory of the latter.     

Charakterisierung nüchterner Räume

The categorySob of sober spaces is a full isomorphismclosed reflective subcategory of the categoryT _o of T_o-spaces (and continuous maps).SobT _o is characterized by: (i) every universal morphism of the adjunction is aT _o-epic embedding, and (ii) everyT _o-epic embedding, whose domain is sober, is a homeomorphism.Sob is the epi-reflective hull of the Sierpinski space D inT _o. A subspace of a sober space is sober, iff it is b-closed. A space is sober, iff it is a b-closed subspace of a power of D.     

Closed structures on categories of topological spaces

The category of all topological spaces and continuous maps and its full subcategory of all T_o-spaces admit (up to isomorphism) precisely one structure of symmetric monoidal closed category (see [2]). In this paper we shall prove the same result for any epireflective subcategory of the category of topological spaces (particularly e.g. for the categories of Hausdorff spaces, regular spaces, Tychonoff spaces).     

Hausdorff L-topological spaces over a base space

In this paper, we introduce the notion of Hausdorff L-topological spaces over a base space, where L is a complete lattice and give some characterizations of these spaces. And we show that the category of Hausdorff L-topological spaces over a base space is a reflective subcategory of the category of L-topological spaces over a base space.     

ON THE EMBEDDING OF TOP IN THE CATEGORY OF STRATIFIED L-TOPOLOGICAL SPACES

§1. Introduction and PreliminariesLet L be a complete lattice. An L-topology on a set X is a subset τ of LX closed withrespect to ?nite meets and arbitrary joins. (X,τ) is called an L-topological space. The L-topology τ is called strati?ed if it contains all the constant maps from X to L, and in this case(X,τ) is called a strati?ed L-topological space. A continuous map between two L-topologicalspaces (X,τX) and (Y,τY ) is a function f : X ?→ Y such that f←(λ) = λ ? f ∈ τX…     

FS-相容Domain的定向完备化及相关范畴性质

引入FS-相容Domain概念,研究FS-相容Domain的性质,主要结果有：（1）FS-相容Domain的收缩核与连续函数空间还是FS-相容Domain;（2）FS-相容Domain是有限生成上集,从而是Scott紧的;（3）FS-相容Domain的定向完备化是FS-Domaln;（4）有最大元的FS-Domain去掉最大元后是FS-相容Domain;（5）证明了以Scott连续映射为态射,FS-相容Domain为对象的范畴FS-CDOM是笛卡儿闭范畴并以FS-Domain范畴FS-DOM作为满的反射子范畴。     

Locale的弱拓扑表达

本文引入了弱拓扑空间的概念,证明了locale范畴与弱拓扑空间范畴的关系类似于拓扑空间范畴与locale范畴的关系。locale范畴严格包含于弱拓扑空间范畴并且与Sober的弱拓扑空间范畴等价。     

On the boundedness of topological categories

Let K be a complete and cocomplete category with a given proper (E,M)-factorization. K is called well-bounded if K is moreover bounded with a generator and cowellpowered with respect to the given factorization. Freyd-Kelly proved the following theorem about well-bounded categories: Let K be a well-bounded category and let Γ be a class of cylinders in the small category C¹, and let all but a set of these cylinders be cones. Then Γ(C,K) is a reflective subcategory of [C,K]. The main results of this paper are: (I) If F: K→L is a Top-functor and L is well-bounded, then K is well-bounded. (II) If U is an E-reflective subcategory of a well-bounded category,then U is again wellbounded. As a corollary one obtains for instance that all coreflective and all epireflective subcategories of the category of topological spaces are well-bounded.     

The Dedekind-MacNeille completion as a reflector

We introduce a special type of order-preserving maps between quasiordered sets, the so-called cut-stable maps. These form the largest morphism class such that the corresponding category of quasiordered sets contains the category of complete lattices and complete homomorphisms as a full reflective subcategory, the reflector being given by the Dedekind-MacNeille completion (alias normal completion or completion by cuts). Suitable restriction of the object class leads to the category of separated quasiordered sets and its full reflective subcategory of completely distributive lattices. Similar reflections are obtained for continuous lattices, algebraic lattices, etc.     

Generation in singularity categories of hypersurfaces of countable representation type

The Orlov spectrum and Rouquier dimension are invariants of a triangulated category to measure how big the category is, and they have been studied actively. In this paper, we investigate the singularity category $$\textsf {D} _{\textsf {sg} }(R)$$ of a hypersurface R of countable representation type. For a thick subcategory $${\mathcal {T}}$$ of $$\textsf {D} _{\textsf {sg} }(R)$$ and a full subcategory $$\mathcal {X}$$ of $${\mathcal {T}}$$, we calculate the Rouquier dimension of $${\mathcal {T}}$$ with respect to $$\mathcal {X}$$. Furthermore, we prove that the level in $$\textsf {D} _{\textsf {sg} }(R)$$ of the residue field of R with respect to each nonzero object is at most one.     

Tensor Products in Categories of Topological Spaces

In this paper symmetric monoidal closed structures on coreflective subcategories of the category of (Hausdorff) topological spaces are studied. We describe all such structures on the category of (Hausdorff) pseudoradial spaces and some of its subcategories and give an example of a coreflective subcategory of the category of Hausdorff topological spaces admitting a proper class of symmetric monoidal closed structures.     

INSTANCES AND RAMIFICATIONS OF THE SEMI-ADJOINT SITUATION I. PRESTABLE REFLECTION AND SYMMETRIC UNADS

Abstract

It is well known that there is a one to one correspondence between idempotent monads in a category and reflective subcategories. In this paper it is examined what replaces the reflective subcategory if the idempotent monad is replaced (a) by a monad and (b) by a symmetric unad. It is shown that in case (a) one obtains the weakly reflective subcategory of objects injective relative to the functor part of the monad. In case (b) one obtains a proto-reflection and it is shown that (for complete categories) the associated orthogonal subcategory is reflective if and only if there exists a free monad associated to the unad.     

PreT 2 Objects in Topological Categories

In previous papers, two notions of pre-Hausdorff (PreT ₂) objects in a topological category were introduced and compared. The main objective of this paper is to show that the full subcategory of PreT ₂ objects is a topological category and all of T ₀, T ₁, and T ₂ objects in this topological category are equivalent. Furthermore, the characterizations of pre-Hausdorff objects in the categories of filter convergence spaces, (constant) local filter convergence spaces, and (constant) stack convergence spaces are given and as a consequence, it is shown that these categories are homotopically trivial.