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Related papers: Upper Bounds on the Automorphism Group of a Graph

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We describe the outer automorphism group of a one-ended fundamental group of a graph of groups, when edge groups are cyclic, and vertex groups are torsion-free with cyclic centralizers. We show that in this case the outer automorphism group…

Group Theory · Mathematics 2025-07-23 Dario Ascari , Montserrat Casals-Ruiz , Ilya Kazachkov

We provide an explicit presentation of the automorphism group of an edge-separated CLTTF Artin group.

Group Theory · Mathematics 2022-01-10 Byung Hee An , Youngjin Cho

A survey article that presents some recent algebraic and model-theoretic results on the automorphism groups of relatively free groups of infinite rank. The topics include topological aspects, generating sets, descripition of automorpisms…

Group Theory · Mathematics 2008-07-29 Vladimir Tolstykh

We obtain a lower bound on each entry of the principal eigenvector of a non-regular connected graph.

Combinatorics · Mathematics 2014-03-11 Felix Goldberg

We are interested in overgroups of the automorphism group of the Rado graph. One class of such overgroups is completely understood; this is the class of reducts. In this article we tie recent work on various other natural overgroups, in…

Combinatorics · Mathematics 2012-05-17 Peter Cameron , Claude Laflamme , Maurice Pouzet , Sam Tarzi , Robert Woodrow

We give an upper bound on the number of perfect matchings in simple graphs with a given number of vertices and edges. We apply this result to give an upper bound on the number of 2-factors in a directed complete bipartite balanced graph on…

Combinatorics · Mathematics 2014-08-01 M. Aaghabali , S. Akbari , S. Friedland , K. Markstrom , Z. Tajfirouz

We prove that, to every abstract group $G$, we can associate a sequence of graphs $\Gamma_n$ such that the automorphism group of $\Gamma_n$ is isomorphic to $G$ and the genus of $\Gamma_n$ is an unbounded function of $n$.

Group Theory · Mathematics 2025-08-29 Marco Barbieri

We give an upper bound on the largest eigenvalue of a graph of given order, size, and girth.

Combinatorics · Mathematics 2007-05-23 Vladimir Nikiforov

We prove new lower and upper bounds on the higher gonalities of finite graphs. These bounds are generalizations of known upper and lower bounds for first gonality to higher gonalities, including upper bounds on gonality involving…

The power graph of a group is the graph whose vertex set is the set of nontrivial elements of group, two elements being adjacent if one is a power of the other. We introduce some way for find the automorphism groups of some graphs. As an…

Group Theory · Mathematics 2019-02-15 Sayyed Heidar Jafari

These lecture notes provide an introduction to automorphism groups of graphs. Some special families of graphs are then discussed, especially the families of Cayley graphs generated by transposition sets.

Discrete Mathematics · Computer Science 2012-06-28 Ashwin Ganesan

We prove upper bounds on the face numbers of simplicial complexes in terms on their girths, in analogy with the Moore bound from graph theory. Our definition of girth generalizes the usual definition for graphs.

Combinatorics · Mathematics 2009-06-04 Michael Goff

The monography examines the problem of constructing a group of automorphisms of a graph. A graph automorphism is a mapping of a set of vertices onto itself that preserves adjacency. The set of such automorphisms forms a vertex group of a…

History and Overview · Mathematics 2024-07-18 Sergey Kurapov , Maxim Davidovsky

We describe the full automorphism group of the directed reduced power graph and the undirected reduced power graph of a finite group. We compute the full automorphism groups of these graphs of several classes of finite groups. Also, we…

Group Theory · Mathematics 2024-11-15 T. Anitha , R. Rajkumar

In this article, we study the outer automorphism group of a group G decomposed as a finite graph of group with finite edge groups and finitely generated vertex groups with at most one end. We show that Out(G) is essentially obtained by…

Group Theory · Mathematics 2013-01-21 Mathieu Carette

Recently, the first author classified finite groups obtained as automorphism groups of smooth plane curves of degree $d \ge 4$ into five types. He gave an upper bound of the order of the automorphism group for each types. For one of them,…

Algebraic Geometry · Mathematics 2017-09-18 Takeshi Harui , Kei Miura , Akira Ohbuchi

We prove that every simplicial automorphism of the free splitting graph of a free group of at least rank 3 is induced by an outer automorphism of the free group.

Group Theory · Mathematics 2009-09-22 Javier Aramayona , Juan Souto

Consider a one-ended word-hyperbolic group. If it is the fundamental group of a graph of free groups with cyclic edge groups then either it is the fundamental group of a surface or it contains a finitely generated one-ended subgroup of…

Group Theory · Mathematics 2014-11-11 Henry Wilton

We prove a tropical analogue of the theorem of Hurwitz: a leafless metric graph of genus $g \ge 2$ has at most $12$ automorphisms when $g = 2$; $2^g g!$ automorphisms when $g \ge 3$. These inequalities are optimal; for each genus, we give…

Combinatorics · Mathematics 2021-10-13 Yusuke Nakamura , JuAe Song

The fine 1-curve graph of a surface is a graph whose vertices are simple closed curves on the surface and whose edges connect vertices that intersect in at most one point. We show that the automorphism group of the fine 1-curve graph is…

Geometric Topology · Mathematics 2023-09-29 Katherine Williams Booth , Daniel Minahan , Roberta Shapiro