Title of article :
Continuous weak selections for products
Author/Authors :
Garcيa-Ferreira، نويسنده , , S. and Miyazaki، نويسنده , , K. and Nogura، نويسنده , , T.، نويسنده ,
Issue Information :
دوماهنامه با شماره پیاپی سال 2013
Abstract :
A weak selection on an infinite set X is a function σ : [ X ] 2 → X such that σ ( { x , y } ) ∈ { x , y } for each { x , y } ∈ [ X ] 2 . A weak selection on a space is said to be continuous if it is a continuous function with respect to the Vietoris topology on [ X ] 2 and the topology on X. We study some topological consequences from the existence of a continuous weak selection on the product X × Y for the following particular cases:(i)
and Y are spaces with one non-isolated point.
space with one non-isolated point and Y is an ordinal space.
plications of the results obtained for these cases, we have that if X is the continuous closed image of suborderable space, Y is not discrete and has countable tightness, and X × Y admits a continuous weak selection, then X is hereditary paracompact. Also, if X is a space, Y is not-discrete and Sel 2 c ( X × Y ) ≠ ∅ , then X is totally disconnected.
Keywords :
product , Weak orderable , Suborderable , Totally disconnected , Continuous weak selection , Ordinal spaces
Journal title :
Topology and its Applications
Journal title :
Topology and its Applications