Jernej
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 May 6 answered Looking for algorithms capable of modifying graph structure Apr 27 awarded Popular Question Apr 24 awarded Popular Question Apr 16 answered Applications Of Strongly Regular Graphs Apr 13 comment Subgroups of the dihedral group D_n modulo Aut(D_n) @DerekHolt Derek, thanks that helped. If you're willing to copy paste your comment into an answer I'll upvote& accept it. Apr 13 comment Edge and vertex connectivity of bipartite graph Do you see that every vertex of this graph has precisely $n-1$ neighbors? How many vertex/edge disjoint paths are between two vertices in $X$. What about a pair of vertices $x \in X,y \in Y$ Apr 13 comment Edge and vertex connectivity of bipartite graph The graph you describe is the disjoint union of $n$ edges. Hence if $n > 1$ the graph is not connected. But as I said I think you're confused with the definition and in fact want to consider $K_{n,n}$-matching. Apr 13 comment Edge and vertex connectivity of bipartite graph So in this case your graph is a matching which is a disconnected graph for $n > 1.$ Apr 13 comment Edge and vertex connectivity of bipartite graph Are you sure you don't mean that every vertex has precisely $n-1$ neighbours? That would give you $K_{n,n}$ minus one matching. Apr 7 comment Subgroups of the dihedral group D_n modulo Aut(D_n) @DerekHolt Hm.. Why is there no fusion for $n$ odd and why is it enough to consider the automorphism $r \mapsto r$ and $s \mapsto rs$? Apr 6 asked Subgroups of the dihedral group D_n modulo Aut(D_n) Apr 4 awarded Notable Question Mar 31 comment All non-isomorphic transitive actions of the Dihedral group @DerekHolt Could you please elaborate a bit more about this? I spent a day on it but don't see an easy way to deduce that for $n$ odd we only need consider subgroups up to conjugacy and the structure of the isomorphism classes under $\rm{Aut}(G)$. Thanks Mar 30 comment All non-isomorphic transitive actions of the Dihedral group @LeeMosher Which theorem exactly? I only covered Lemma1.6B which allows one to find transitive actions up to equivalence. Mar 30 comment All non-isomorphic transitive actions of the Dihedral group @LeeMosher Yes, but I don't know how this gives me all actions of $D_n$ modulo isomorphism Mar 30 asked All non-isomorphic transitive actions of the Dihedral group Mar 27 accepted Outer automorphism of $S_6$ and conjugate stabilizers Mar 25 comment Outer automorphism of $S_6$ and conjugate stabilizers Could you please clarify why $g((1,2))$ commutes with every element of the stabilizer of $1$ and $2$? Why does it follow that $g$ is the identity map? Is it because it fixes all the transpositions? Mar 25 asked Outer automorphism of $S_6$ and conjugate stabilizers Mar 7 accepted Bounding probability of some events with bounded depdendence