Skip to main content

All Questions

Filter by
Sorted by
Tagged with
20 votes
4 answers
2k views

Cayley graph of $A_5$ with generators $(1,2,3,4,5),(1,4,3,2,5)$

The Cayley graph of $A_5$ with two generators of order 5 seems rather complicated. What is its graph genus (orientable or non-orientable)? The best I could get by trial and error is an embedding ...
Bjørn Kjos-Hanssen's user avatar
1 vote
1 answer
116 views

On graph imbedding genus clarification

Given a graph the minimum genus $g$ is the minimum number of handles needed so that there an imbedding of the graph on the surface with no edge crossings. If the graph is of genus $g$ then is there ...
Turbo's user avatar
  • 13.9k
2 votes
1 answer
270 views

Loop of crosscaps and Euler characteristic

The first picture below has $v=12$ vertices, $e=16$ edges, and seems to have $k=4$ crosscaps (denoted by something like $\oplus$). The number of faces $f$ should satisfy $$v-e+f=2-k$$ which gives $f=2$...
Bjørn Kjos-Hanssen's user avatar
12 votes
3 answers
582 views

Can we map every graph in the plane such that all induced cycles selfintersect?

Suppose we have a graph G. Is it true that we can map its vertices to the plane such that when connecting neighboring vertices with segments, then any induced cycle of G that has length at least 4 ...
domotorp's user avatar
  • 18.7k
8 votes
2 answers
369 views

Spectral techniques for genus of a graph

A generic question: are there any spectral techniques to estimate the genus of a graph? I am interested in complete balance multipartite graph.
Moh514's user avatar
  • 461