CONNEXION PROPERTIES AND FACTORISATION THEOREMS
- 1 January 1977
- journal article
- research article
- Published by Taylor & Francis in Quaestiones Mathematicae
- Vol. 2 (1-3) , 103-112
- https://doi.org/10.1080/16073606.1977.9632536
Abstract
With the introduction of several new factorisation theorems, this paper is intended to show that previous efforts of the authors [3] [5] and of Strecker [15] to describe the factorisations involving connectedness are incomplete. In Section 1 we give a purely topological construction of such a factorisation, in which the right factor is the class of spreads and the left factor has a certain property hereditarily: crucially, not all members of the left factor need be quotients. Section 2 shows that, given a left factor consisting of onto maps in the category T of topological spaces, then the class of mappings with the relevant properties hereditarily is also a left factor, and the result of section 1 is a particular case of this. Section 3 combines the material in [3] on intrinsic connexion properties with ideas of Preuss (see [1]) on disconnectednesses to yield another range of factorisations, for example, involving the maps with strongly connected fibres; and Section 4 notes some outstánding problems which our work has provoked.Keywords
This publication has 7 references indexed in Scilit:
- Categorical cutsGeneral Topology and its Applications, 1976
- Projective resolutions of topological spacesJournal of Pure and Applied Algebra, 1976
- Connectednesses and disconnectednesses in topologyGeneral Topology and its Applications, 1975
- Factorisation theorems and projective spaces in topologyMathematische Zeitschrift, 1972
- Concordant mappings and the concordant-dissonant factorization of an arbitrary continuous functionProceedings of the American Mathematical Society, 1971
- CutsActa Mathematica, 1964
- Sur les ensembles connexes et non connexesFundamenta Mathematicae, 1921