English

Sequence of dualizations of topological spaces is finite

General Topology 2007-05-23 v1

Abstract

Problem 540 of J. D. Lawson and M. Mislove in Open Problems in Topology asks whether the process of taking duals terminate after finitely many steps with topologies that are duals of each other. The problem for T1T_1 spaces was already solved by G. E. Strecker in 1966. For certain topologies on hyperspaces (which are not necessarily T1T_1), the main question was in the positive answered by Bruce S. Burdick and his solution was presented on The First Turkish International Conference on Topology in Istanbul in 2000. In this paper we bring a complete and positive solution of the problem for all topological spaces. We show that for any topological space (X,τ)(X,\tau) it follows τdd=τdddd\tau^{dd}=\tau^{dddd}. Further, we classify topological spaces with respect to the number of generated topologies by the process of taking duals.

Keywords

Cite

@article{arxiv.math/0204132,
  title  = {Sequence of dualizations of topological spaces is finite},
  author = {Martin Maria Kovar},
  journal= {arXiv preprint arXiv:math/0204132},
  year   = {2007}
}

Comments

9 pages. Reprinted from Theoretical Computer Science B, in press, Martin Maria Kovar, The solution to Problem 540