Let $C_0$ denote the set of all non-decreasing continuous functions \linebreak $f: (0, 1] \to (0, 1]$ such that $\lim_{x\to 0^+}f(x) =0$ and $f(x) \leq x$ for $x\in (0, 1]$ and let $A$ be a measurable subset of the plane. We define the notion of a density point of $A$ with respect to $f$. This is a starting point to introduce the mapping $D_f$ defined on the family of all measurable subsets of the plane, which is so-called lower density. The mapping $D_f$ leads to the topology $\Cal T_f$, analogously as for the density topology. The properties of the topologies $\Cal T_f$ are considered.
@article{46, title = {Density topologies on the plane between ordinary and strong}, journal = {Tatra Mountains Mathematical Publications}, volume = {43}, year = {2009}, doi = {10.2478/tatra.v44i0.46}, language = {EN}, url = {http://dml.mathdoc.fr/item/46} }
Wagner-Bojakowska, Elżbieta; Wilczyński, Władysław. Density topologies on the plane between ordinary and strong. Tatra Mountains Mathematical Publications, Tome 43 (2009) . doi : 10.2478/tatra.v44i0.46. http://gdmltest.u-ga.fr/item/46/