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Questions about the branch of algebra that deals with groups.

8 votes

Normal subgroups of an extension of the Higman group

The answer to part (a) of your question is that the normal closure of $a^{k_1}\cdot t\cdot a^{k_2} \cdot t \cdot a^{k_3}$ is always equal to the normal closure of $a$ and $t^2$. This is because the qu …
andrew's user avatar
  • 171
4 votes

Normal subgroups of an extension of the Higman group

The answer to part (b) is that the normal closure of the word given in part (b) is always equal to $G$. To see this, consider the quotient of $G$ by adding in this case a relation $a^{k}ta^{l}ta^{m}t …
andrew's user avatar
  • 171
0 votes

Normal subgroups of an extension of the Higman group

Let me try to answer the first query mentioned in part (c). Let $G=<a,t|bab^{-1}=a^{2},b=tat^{-1},t^{4}=1>$ and $H=<a,b,c,d|bab^{-1}=a^{2},cbc^{-1}=c^{2},dcd^{-1}=c^{2},ada^{-1}=d^{2}>$ the Higman gr …
andrew's user avatar
  • 171