The concept of a Cayley map is one of the central concepts of the part of Topological Graph Theory focused on highly symmetric maps. A Cayley map is a 2-cell embedding of a Cayley graph into an orientable surface which admits all the left multiplications by the elements of the group as automorphisms of the map. A Cayley map is regular if its automorphism group acts transitively on its set of darts. The automorphism group of a Cayley map is a cyclic complementary extension of its underlying group, where the cyclic part is generated by a special group mapping called skew-morphism. All cyclic complementary extensions are known to give rise to skew-morphisms, and all skew-morphisms give rise to specific cyclic complementary extensions called skew-products. However, not all cyclic complementary extensions are skew-products; leaving a gap in our understanding of cyclic complementary extensions of finite groups. Recently, together with Kan Hu, we have been able to fill this gap by introducing a generalization of the power function of a skew-morphism we call extended power function, and by finding a universal construction of cyclic complementary extensions of groups by skew-morphisms and their extended power functions. We have shown that all cyclic complementary extensions are constructed in this way.
Universal construction of cyclic complementary extensions of finite groups inspired by the structure of automorphism groups of regular Cayley maps
10.10.2024 14:00 - 15:00
Organiser:
G. Arzhantseva, Ch. Cashen
Location: