Abstract
The paper deals with real functions of real variable continuous in the density topology on the domain and on the range. The set on which such functions preserve upper outer density is described. Also the class of homeomorphisms continuous in the density topology is considered. At last some problems of differentiability are analysed.
Similar content being viewed by others
References
Bruckner A. M.,Density-preserving homeomorphisms and the theorem of Maximoff, Quart. J. Math. Oxford, (2),21 (1970), 337–347.
Bruckner A. M.,Differentiation of Real Functions, Lecture Notes in Mathematics659, Springer 1978.
Filipczak F. M.,On the structure of the set of symmetric non-differentiability of a continuous function (in Polish), Lodz University, 1973.
Niewiarowski J.,Density-preserving homeomorphisms, Fund. Math.,106 (1980), 77–87.
Ostaszewski K.,Continuity in the density topology, Real Anal. Exchange, (1982), 259–270.
Ostaszewski K.,Two modifications of the approximate derivative, Demonstratio Math.,15, No. 3 (1982), 899–911.
Sindalovski G.,Some questions of continuity and differentiability of measurable functions (in Russian), Izv. Akad. Nauk SSSR (Math.)22 (1958), 395–432.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ostaszewski, K. Continuity in the density topology II. Rend. Circ. Mat. Palermo 32, 398–414 (1983). https://doi.org/10.1007/BF02848542
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02848542