Тип публикации: статья из журнала (материалы конференций, опубликованные в журналах)
Конференция: Czech-Slovak International Symposium on Graph Theory, Combinatorics, Algorithms and Applications; Slovakia, CZECH REPUBLIC; Slovakia, CZECH REPUBLIC
Год издания: 2015
Идентификатор DOI: 10.1016/j.disc.2015.03.003
Ключевые слова: Riemann surface, Graph, Fundamental group, Automorphism group, Harmonic morphism, Branched covering
Аннотация: The aim of the paper is to find discrete versions of the Wiman theorem which states that the maximum possible order of an automorphism of a Riemann surface of genus g >= 2 is 4g+2. The role of a Riemann surface in this paper is played by a finite connected graph. The genus of a graph is defined as the rank of its homology group. LeПоказать полностьюt Z(N) be a cyclic group acting freely on the set of directed edges of a graph X of genus g >= 2. We prove that N = 2. The latter takes a place when the signature of the orbifold X/Z(N) is (0; 2, 2g). (C) 2015 Elsevier B.V. All rights reserved.
Журнал: DISCRETE MATHEMATICS
Выпуск журнала: Vol. 338, Is. 10
Номера страниц: 1793-1800
ISSN журнала: 0012365X
Место издания: AMSTERDAM
Издатель: ELSEVIER SCIENCE BV