Automorphism of these Cayley graphs

  • Thread starter tsang
  • Start date
  • Tags
    Graphs
In summary, the conversation discusses the topic of finding automorphisms on three specific Cayley graphs: <a,b,c,d | [ab,cd]=1>; <a,b,c,d | abcda^(-1)b^(-1)c^(-1)d^(-1)=1>; and <a,b,c,d | [a,b][c,d]=1>. The first graph resembles Z^2 with eight generators, while the second and third are octagons on a hyperbolic plane. The speaker expresses confusion on how to find automorphisms for Z^2 and seeks help in finding automorphisms for the three Cayley graphs. Additional sources are suggested for further assistance.
  • #1
tsang
15
0
Hi everyone, I need a lot help on how to find automorphisms on these particular Cayley graphs.

I have three groups here: <a,b,c,d | [ab,cd]=1>; <a,b,c,d | abcda^(-1)b^(-1)c^(-1)d^(-1)=1>; <a,b,c,d | [a,b][c,d]=1>.

I finally got three Cayley graphs down, first one is like Z^2, but with each vertice has eight other vertices come out due to the fact of eight generators. Second and third Cayley graphs both have to be done on hyperbolic plane as it is octagons with each vertice has other eight octagons. I have checked the graphs are right.

I thought to try to least find automorphism for simple Z^2, which would just have cayley graphs as grid lines, but I'm even quite confused with how to do this. By starting looking at some symmetries, what should I do next then?

Also, how can I find automorphisms of above three Cayley graphs? Can anyone please help me a bit? Thanks a lot.
 
Physics news on Phys.org

What is an automorphism of a Cayley graph?

An automorphism of a Cayley graph is a bijective function that preserves the structure of the graph. In other words, it is a mapping of the vertices of the graph onto itself that preserves the adjacency relationships between vertices.

Why are automorphisms important in the study of Cayley graphs?

Automorphisms can provide insight into the underlying structure and symmetries of a Cayley graph, which can be useful in understanding its properties and applications. They are also important in group theory, as they are closely related to group homomorphisms.

How do you determine the automorphisms of a Cayley graph?

The automorphisms of a Cayley graph can be determined by examining the group elements and their corresponding actions on the graph. This can be done by hand for small graphs, but for larger graphs, computer algorithms are often used.

What is an example of an automorphism of a Cayley graph?

An example of an automorphism of a Cayley graph is the identity mapping, which maps each vertex onto itself. Another example is a rotation or reflection of the graph, which preserves the adjacency relationships between vertices.

Can a Cayley graph have non-trivial automorphisms?

Yes, a Cayley graph can have non-trivial automorphisms, meaning it has automorphisms other than the identity mapping. These non-trivial automorphisms can provide important information about the structure and symmetries of the graph.

Similar threads

Replies
2
Views
917
  • Linear and Abstract Algebra
Replies
2
Views
1K
  • Linear and Abstract Algebra
Replies
5
Views
2K
  • Linear and Abstract Algebra
Replies
1
Views
2K
  • Linear and Abstract Algebra
Replies
2
Views
2K
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
6
Views
962
  • Linear and Abstract Algebra
Replies
8
Views
1K
Replies
49
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
4
Views
1K
Back
Top