RUS  ENG
Full version
JOURNALS // Computer Research and Modeling // Archive

Computer Research and Modeling, 2009 Volume 1, Issue 3, Pages 243–249 (Mi crm642)

MATHEMATICAL MODELING AND NUMERICAL SIMULATION

Representation of groups by automorphisms of normal topological spaces

A. V. Koganov

Scientific-Research Institute for System Studies, Russian Academy of Sciences (NIISI RAN), Nakhimovskii av. 36-1, 117218, Moscow, Russia

Abstract: The famous fact [3, 5] of existence of an exact representation for any finite group in the form of the full automorphism group of a finite graph was generalize in [4]. For an arbitrary group exact representation exists in the form of the full automorphism group of Kolmogorov topological space (weak type of separability $T_0$). For a finite group a finite space may be chosen, thus allowing to restore a finite graph with the same number of vertices and having the same automorphism group. Such topological spaces and graphs are called topological imprints and graph imprints of a group (T-imprints and G-imprints, respectively). The question of maximum type of separability of a topological space for which T-imprint can be obtained for any group is open. The author proves that the problem can be solved for the class of normal topology (maximal type of separability $\mathrm{T}_4+\mathrm{T}_1$). Special finite T-imprint for a symmetric group may be obtained as a discrete topology; for any other group minimal cardinality of normal T-imprint is countable. There is a generic procedure to construct a T-imprint for any group. For a finite group this procedure allows finite space partitioning into subspaces having G-imprint of the original group as their connectivity graphs.

Keywords: group theory, automorphisms, topological spaces.

Received: 10.04.2009
Revised: 27.06.2009

DOI: 10.20537/2076-7633-2009-1-3-243-249



© Steklov Math. Inst. of RAS, 2024