Deriving the Discrete Heisenberg Group generators.












0












$begingroup$



How can we derive the generators of the Discrete Heisnberg Group?




Everyone seems to just state this as a given and never actually derive it from scratch.



I'm looking for a (somewhat) elementary derivation










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
    $endgroup$
    – Lorenzo
    Dec 18 '18 at 15:52










  • $begingroup$
    I have no idea how i missed that, but still a derivation from scratch would be nice
    $endgroup$
    – user371732
    Dec 18 '18 at 16:13
















0












$begingroup$



How can we derive the generators of the Discrete Heisnberg Group?




Everyone seems to just state this as a given and never actually derive it from scratch.



I'm looking for a (somewhat) elementary derivation










share|cite|improve this question











$endgroup$








  • 2




    $begingroup$
    The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
    $endgroup$
    – Lorenzo
    Dec 18 '18 at 15:52










  • $begingroup$
    I have no idea how i missed that, but still a derivation from scratch would be nice
    $endgroup$
    – user371732
    Dec 18 '18 at 16:13














0












0








0





$begingroup$



How can we derive the generators of the Discrete Heisnberg Group?




Everyone seems to just state this as a given and never actually derive it from scratch.



I'm looking for a (somewhat) elementary derivation










share|cite|improve this question











$endgroup$





How can we derive the generators of the Discrete Heisnberg Group?




Everyone seems to just state this as a given and never actually derive it from scratch.



I'm looking for a (somewhat) elementary derivation







group-theory group-presentation






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Dec 21 '18 at 17:36









Shaun

9,789113684




9,789113684










asked Dec 18 '18 at 15:45







user371732















  • 2




    $begingroup$
    The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
    $endgroup$
    – Lorenzo
    Dec 18 '18 at 15:52










  • $begingroup$
    I have no idea how i missed that, but still a derivation from scratch would be nice
    $endgroup$
    – user371732
    Dec 18 '18 at 16:13














  • 2




    $begingroup$
    The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
    $endgroup$
    – Lorenzo
    Dec 18 '18 at 15:52










  • $begingroup$
    I have no idea how i missed that, but still a derivation from scratch would be nice
    $endgroup$
    – user371732
    Dec 18 '18 at 16:13








2




2




$begingroup$
The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
$endgroup$
– Lorenzo
Dec 18 '18 at 15:52




$begingroup$
The Wikipedia page gives an explicit formula for an arbitrary element in terms of the generators x and y (z can be written in terms of x and y also, Wikipedia gives the computation for that). This is under the section "discrete Heisenberg group". You can try to verify these formulas by computation.
$endgroup$
– Lorenzo
Dec 18 '18 at 15:52












$begingroup$
I have no idea how i missed that, but still a derivation from scratch would be nice
$endgroup$
– user371732
Dec 18 '18 at 16:13




$begingroup$
I have no idea how i missed that, but still a derivation from scratch would be nice
$endgroup$
– user371732
Dec 18 '18 at 16:13










1 Answer
1






active

oldest

votes


















1












$begingroup$

Since the discrete Heisenberg group is defined to be the subgroup of $GL_3(Bbb{Z})$ consisiting of upper-unitriangular matrices, it is clear that the generators are given by $x,y,z$, where
$$
begin{pmatrix} 1 & a & c\ 0 & 1 & b\ 0 & 0 & 1\ end{pmatrix}=y^bz^cx^a, $$

see Wikipedia. Here it is enough to consider $x$ and $y$ since $z=[x,y]$ by matrix multiplication.






share|cite|improve this answer









$endgroup$













    Your Answer





    StackExchange.ifUsing("editor", function () {
    return StackExchange.using("mathjaxEditing", function () {
    StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
    StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
    });
    });
    }, "mathjax-editing");

    StackExchange.ready(function() {
    var channelOptions = {
    tags: "".split(" "),
    id: "69"
    };
    initTagRenderer("".split(" "), "".split(" "), channelOptions);

    StackExchange.using("externalEditor", function() {
    // Have to fire editor after snippets, if snippets enabled
    if (StackExchange.settings.snippets.snippetsEnabled) {
    StackExchange.using("snippets", function() {
    createEditor();
    });
    }
    else {
    createEditor();
    }
    });

    function createEditor() {
    StackExchange.prepareEditor({
    heartbeatType: 'answer',
    autoActivateHeartbeat: false,
    convertImagesToLinks: true,
    noModals: true,
    showLowRepImageUploadWarning: true,
    reputationToPostImages: 10,
    bindNavPrevention: true,
    postfix: "",
    imageUploader: {
    brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
    contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
    allowUrls: true
    },
    noCode: true, onDemand: true,
    discardSelector: ".discard-answer"
    ,immediatelyShowMarkdownHelp:true
    });


    }
    });














    draft saved

    draft discarded


















    StackExchange.ready(
    function () {
    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3045310%2fderiving-the-discrete-heisenberg-group-generators%23new-answer', 'question_page');
    }
    );

    Post as a guest















    Required, but never shown
























    1 Answer
    1






    active

    oldest

    votes








    1 Answer
    1






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes









    1












    $begingroup$

    Since the discrete Heisenberg group is defined to be the subgroup of $GL_3(Bbb{Z})$ consisiting of upper-unitriangular matrices, it is clear that the generators are given by $x,y,z$, where
    $$
    begin{pmatrix} 1 & a & c\ 0 & 1 & b\ 0 & 0 & 1\ end{pmatrix}=y^bz^cx^a, $$

    see Wikipedia. Here it is enough to consider $x$ and $y$ since $z=[x,y]$ by matrix multiplication.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      Since the discrete Heisenberg group is defined to be the subgroup of $GL_3(Bbb{Z})$ consisiting of upper-unitriangular matrices, it is clear that the generators are given by $x,y,z$, where
      $$
      begin{pmatrix} 1 & a & c\ 0 & 1 & b\ 0 & 0 & 1\ end{pmatrix}=y^bz^cx^a, $$

      see Wikipedia. Here it is enough to consider $x$ and $y$ since $z=[x,y]$ by matrix multiplication.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        Since the discrete Heisenberg group is defined to be the subgroup of $GL_3(Bbb{Z})$ consisiting of upper-unitriangular matrices, it is clear that the generators are given by $x,y,z$, where
        $$
        begin{pmatrix} 1 & a & c\ 0 & 1 & b\ 0 & 0 & 1\ end{pmatrix}=y^bz^cx^a, $$

        see Wikipedia. Here it is enough to consider $x$ and $y$ since $z=[x,y]$ by matrix multiplication.






        share|cite|improve this answer









        $endgroup$



        Since the discrete Heisenberg group is defined to be the subgroup of $GL_3(Bbb{Z})$ consisiting of upper-unitriangular matrices, it is clear that the generators are given by $x,y,z$, where
        $$
        begin{pmatrix} 1 & a & c\ 0 & 1 & b\ 0 & 0 & 1\ end{pmatrix}=y^bz^cx^a, $$

        see Wikipedia. Here it is enough to consider $x$ and $y$ since $z=[x,y]$ by matrix multiplication.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Dec 18 '18 at 16:14









        Dietrich BurdeDietrich Burde

        81.4k648106




        81.4k648106






























            draft saved

            draft discarded




















































            Thanks for contributing an answer to Mathematics Stack Exchange!


            • Please be sure to answer the question. Provide details and share your research!

            But avoid



            • Asking for help, clarification, or responding to other answers.

            • Making statements based on opinion; back them up with references or personal experience.


            Use MathJax to format equations. MathJax reference.


            To learn more, see our tips on writing great answers.




            draft saved


            draft discarded














            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3045310%2fderiving-the-discrete-heisenberg-group-generators%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown





















































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown

































            Required, but never shown














            Required, but never shown












            Required, but never shown







            Required, but never shown







            Popular posts from this blog

            Plaza Victoria

            In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

            How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...