F-nodec spaces

Lobna Dridi, Abdelwaheb Mhemdi, Tarek Turki
2015 Applied General Topology  
Following Van Douwen, a topological space is said to be nodec if it satisfies one of the following equivalent conditions: (i) every nowhere dense subset of X, is closed; (ii) every nowhere dense subset of X, is closed discrete; (iii) every subset containing a dense open subset is open. This paper deals with a characterization of topological spaces X such that F(X) is a nodec space for some covariant functor F from the category Top to itself. T0, ρ and FH functors are completely studied.
more » ... , we characterize maps f given by a flow (X, f ) in the category Set such that (X, P(f )) is nodec (resp., T0-nodec), where P(f ) is a topology on X whose closed sets are precisely f -invariant sets.
doi:10.4995/agt.2015.3141 fatcat:jwbmw7ec5fgk3iwk5qo3i2c4ya