函数空间映射的一个注记

对于拓扑空间Y,连续映射f∶X′→X可诱导函数空间映射f#Y∶YX→YX′,其中f#Y(g)=g f,g∶X→Y.文献[1]证明了:若f∶X′→X为上纤维化,则f#Y∶YX→YX′是纤维化.本文将证明:其逆命题也成立.     

Homotopy ends and Thomason model categories

No Abstract.       

Facets of Descent, II

Methods of internal-category theory are applied to show that the split epimorphisms in a category C are exactly the morphisms which are effective for descent with respect to any fibration over C (or to any C-indexed category). In the same context, composition-cancellation rules for effective descent morphisms are established and being applied to (suitably defined) locally-split epimorphisms.     

h0b1^3在π＊Ⅴ（1）中的收敛性

利用Adams谱序列和May谱序列，发现了Smith—Toda谱Ⅴ（1）的稳定同伦群中的一个非零元素，此元素在Adams谱序列里由h0b1^3表示．     

近似同胚的同伦性质*

近似同胚是拓扑学中的一个重要概念，关于近似同胚的研究也有不少的结果．但已有的研究基本上是关于近似同胚的一般拓扑性质的．本文讨论近似同胚的代数拓扑性质，证明了在空间是局部等连通、Ｔ２的条件下，近似同胚同伦于某一同胚，因而是一同伦等价．     

h_0b_1~3在π_*V(1)中的收敛性

利用Adams谱序列和May谱序列,发现了Smith-Toda谱V(1)的稳定同伦群中的一个非零元素,此元素在Adams谱序列里由h0b13表示．     

Digital Cofibration and Digital Lusternik-Schnirelmann Category in the Sense of Subdivision

In this paper, using the notion of subdivision, the authors generalize the definition of cofibration in digital topology and show that this kind of cofibration is injective in the sense of subdivision. Meanwhile, they give the necessary condition under which a digital map is a cofibration. Furthermore, they consider the Lusternik-Schnirelmann category of digital maps in the sense of subdivision and give several fundamental homotopy properties about it.