Conjugacy in right-angled Artin groups












5












$begingroup$


I am looking for a reference containing the following result:




Let $a$ and $b$ be two elements of a right-angled Artin group $A$. Assume that $a$ and $b$ have minimal length (with respect to the canonical generating set of $A$) in their conjugacy classes. Let $a_1 cdots a_n$ and $b_1 cdots b_m$ be words of minimal length representing $a$ and $b$ respectively. If $a$ and $b$ are conjugate in $A$, then $a_1 cdots a_n$ can be obtained from $b_1 cdots b_m$ by applying the following operations: permutation of two successive letters which commute, and cyclic permutation.




I am sure that it is written somewhere, but I am not able to find where.










share|cite|improve this question









$endgroup$

















    5












    $begingroup$


    I am looking for a reference containing the following result:




    Let $a$ and $b$ be two elements of a right-angled Artin group $A$. Assume that $a$ and $b$ have minimal length (with respect to the canonical generating set of $A$) in their conjugacy classes. Let $a_1 cdots a_n$ and $b_1 cdots b_m$ be words of minimal length representing $a$ and $b$ respectively. If $a$ and $b$ are conjugate in $A$, then $a_1 cdots a_n$ can be obtained from $b_1 cdots b_m$ by applying the following operations: permutation of two successive letters which commute, and cyclic permutation.




    I am sure that it is written somewhere, but I am not able to find where.










    share|cite|improve this question









    $endgroup$















      5












      5








      5


      2



      $begingroup$


      I am looking for a reference containing the following result:




      Let $a$ and $b$ be two elements of a right-angled Artin group $A$. Assume that $a$ and $b$ have minimal length (with respect to the canonical generating set of $A$) in their conjugacy classes. Let $a_1 cdots a_n$ and $b_1 cdots b_m$ be words of minimal length representing $a$ and $b$ respectively. If $a$ and $b$ are conjugate in $A$, then $a_1 cdots a_n$ can be obtained from $b_1 cdots b_m$ by applying the following operations: permutation of two successive letters which commute, and cyclic permutation.




      I am sure that it is written somewhere, but I am not able to find where.










      share|cite|improve this question









      $endgroup$




      I am looking for a reference containing the following result:




      Let $a$ and $b$ be two elements of a right-angled Artin group $A$. Assume that $a$ and $b$ have minimal length (with respect to the canonical generating set of $A$) in their conjugacy classes. Let $a_1 cdots a_n$ and $b_1 cdots b_m$ be words of minimal length representing $a$ and $b$ respectively. If $a$ and $b$ are conjugate in $A$, then $a_1 cdots a_n$ can be obtained from $b_1 cdots b_m$ by applying the following operations: permutation of two successive letters which commute, and cyclic permutation.




      I am sure that it is written somewhere, but I am not able to find where.







      reference-request gr.group-theory combinatorial-group-theory






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 28 '18 at 20:08









      AGenevoisAGenevois

      1,507815




      1,507815






















          3 Answers
          3






          active

          oldest

          votes


















          2












          $begingroup$

          Look at Lemma 9 of https://arxiv.org/abs/0802.1771 for what you want.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
            $endgroup$
            – AGenevois
            Dec 29 '18 at 7:10










          • $begingroup$
            I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:04










          • $begingroup$
            The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:30



















          1












          $begingroup$

          I accepted Benjamin Steinberg's answer, but I would like to clarify the situation little bit:




          • As mentioned by Benjamin Steinberg, the statement appears without proof as Lemma 9 in the article The conjugacy problem in subgroups of right-angled Artin groups, J. Crisp, E. Godelle, B. Wiest. So it is a well-known result but a proof does not seem to be available in the litetature. However, an argument could be extracted from other known results. In particular, a similar statement for free partially commutative monoids can be found in the article On some equations in free partially commutative monoids, C. Duboc.


          • A combinatorial proof in the more general context of graph products of groups can be found in the article On conjugacy separability of graph products of groups, M. Ferov (see Lemma 3.12).


          • A geometric proof of the same statement can be found in my prepring On the geometry of van Kampen diagrams of graph products of groups. (I was looking for a reference for right-angled Artin groups to include it in the paper.)







          share|cite|improve this answer









          $endgroup$





















            -1












            $begingroup$

            I think Theorem 4.14 in Ric Wade's survey [1] should suffice. Ric also gives a discussion of where one can find other (older) proofs of the existence of a normal form for elements in RAAGs; I think he mentions Green's thesis [2] as the oldest source containing a proof.



            [1] https://arxiv.org/pdf/1109.1722.pdf



            [2] Elisabeth R. Green. Graph products of groups. PhD thesis, The University of Leeds, 1990.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
              $endgroup$
              – AGenevois
              Jan 5 at 6:45











            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: "504"
            };
            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%2fmathoverflow.net%2fquestions%2f319679%2fconjugacy-in-right-angled-artin-groups%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            3 Answers
            3






            active

            oldest

            votes








            3 Answers
            3






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            2












            $begingroup$

            Look at Lemma 9 of https://arxiv.org/abs/0802.1771 for what you want.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
              $endgroup$
              – AGenevois
              Dec 29 '18 at 7:10










            • $begingroup$
              I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:04










            • $begingroup$
              The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:30
















            2












            $begingroup$

            Look at Lemma 9 of https://arxiv.org/abs/0802.1771 for what you want.






            share|cite|improve this answer









            $endgroup$













            • $begingroup$
              Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
              $endgroup$
              – AGenevois
              Dec 29 '18 at 7:10










            • $begingroup$
              I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:04










            • $begingroup$
              The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:30














            2












            2








            2





            $begingroup$

            Look at Lemma 9 of https://arxiv.org/abs/0802.1771 for what you want.






            share|cite|improve this answer









            $endgroup$



            Look at Lemma 9 of https://arxiv.org/abs/0802.1771 for what you want.







            share|cite|improve this answer












            share|cite|improve this answer



            share|cite|improve this answer










            answered Dec 28 '18 at 20:54









            Benjamin SteinbergBenjamin Steinberg

            23.4k265125




            23.4k265125












            • $begingroup$
              Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
              $endgroup$
              – AGenevois
              Dec 29 '18 at 7:10










            • $begingroup$
              I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:04










            • $begingroup$
              The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:30


















            • $begingroup$
              Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
              $endgroup$
              – AGenevois
              Dec 29 '18 at 7:10










            • $begingroup$
              I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:04










            • $begingroup$
              The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
              $endgroup$
              – Benjamin Steinberg
              Dec 29 '18 at 11:30
















            $begingroup$
            Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
            $endgroup$
            – AGenevois
            Dec 29 '18 at 7:10




            $begingroup$
            Yes, but the statement is essentially referred to as a well-known result. It is not proved in the article and no reference is mentioned.
            $endgroup$
            – AGenevois
            Dec 29 '18 at 7:10












            $begingroup$
            I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:04




            $begingroup$
            I think the monoid version is proved in the references to which it originality attributes the result. I think the group version is not much different.
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:04












            $begingroup$
            The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:30




            $begingroup$
            The point is if you start with a cyclically reduced word then it is conjugate to another cyclically reduced word in the group iff they are conjugate in the corresponding free partially commutative monoid and then you can apply reference [23] of the paper which I believe does what you want in the monoid context
            $endgroup$
            – Benjamin Steinberg
            Dec 29 '18 at 11:30











            1












            $begingroup$

            I accepted Benjamin Steinberg's answer, but I would like to clarify the situation little bit:




            • As mentioned by Benjamin Steinberg, the statement appears without proof as Lemma 9 in the article The conjugacy problem in subgroups of right-angled Artin groups, J. Crisp, E. Godelle, B. Wiest. So it is a well-known result but a proof does not seem to be available in the litetature. However, an argument could be extracted from other known results. In particular, a similar statement for free partially commutative monoids can be found in the article On some equations in free partially commutative monoids, C. Duboc.


            • A combinatorial proof in the more general context of graph products of groups can be found in the article On conjugacy separability of graph products of groups, M. Ferov (see Lemma 3.12).


            • A geometric proof of the same statement can be found in my prepring On the geometry of van Kampen diagrams of graph products of groups. (I was looking for a reference for right-angled Artin groups to include it in the paper.)







            share|cite|improve this answer









            $endgroup$


















              1












              $begingroup$

              I accepted Benjamin Steinberg's answer, but I would like to clarify the situation little bit:




              • As mentioned by Benjamin Steinberg, the statement appears without proof as Lemma 9 in the article The conjugacy problem in subgroups of right-angled Artin groups, J. Crisp, E. Godelle, B. Wiest. So it is a well-known result but a proof does not seem to be available in the litetature. However, an argument could be extracted from other known results. In particular, a similar statement for free partially commutative monoids can be found in the article On some equations in free partially commutative monoids, C. Duboc.


              • A combinatorial proof in the more general context of graph products of groups can be found in the article On conjugacy separability of graph products of groups, M. Ferov (see Lemma 3.12).


              • A geometric proof of the same statement can be found in my prepring On the geometry of van Kampen diagrams of graph products of groups. (I was looking for a reference for right-angled Artin groups to include it in the paper.)







              share|cite|improve this answer









              $endgroup$
















                1












                1








                1





                $begingroup$

                I accepted Benjamin Steinberg's answer, but I would like to clarify the situation little bit:




                • As mentioned by Benjamin Steinberg, the statement appears without proof as Lemma 9 in the article The conjugacy problem in subgroups of right-angled Artin groups, J. Crisp, E. Godelle, B. Wiest. So it is a well-known result but a proof does not seem to be available in the litetature. However, an argument could be extracted from other known results. In particular, a similar statement for free partially commutative monoids can be found in the article On some equations in free partially commutative monoids, C. Duboc.


                • A combinatorial proof in the more general context of graph products of groups can be found in the article On conjugacy separability of graph products of groups, M. Ferov (see Lemma 3.12).


                • A geometric proof of the same statement can be found in my prepring On the geometry of van Kampen diagrams of graph products of groups. (I was looking for a reference for right-angled Artin groups to include it in the paper.)







                share|cite|improve this answer









                $endgroup$



                I accepted Benjamin Steinberg's answer, but I would like to clarify the situation little bit:




                • As mentioned by Benjamin Steinberg, the statement appears without proof as Lemma 9 in the article The conjugacy problem in subgroups of right-angled Artin groups, J. Crisp, E. Godelle, B. Wiest. So it is a well-known result but a proof does not seem to be available in the litetature. However, an argument could be extracted from other known results. In particular, a similar statement for free partially commutative monoids can be found in the article On some equations in free partially commutative monoids, C. Duboc.


                • A combinatorial proof in the more general context of graph products of groups can be found in the article On conjugacy separability of graph products of groups, M. Ferov (see Lemma 3.12).


                • A geometric proof of the same statement can be found in my prepring On the geometry of van Kampen diagrams of graph products of groups. (I was looking for a reference for right-angled Artin groups to include it in the paper.)








                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Feb 14 at 9:29









                AGenevoisAGenevois

                1,507815




                1,507815























                    -1












                    $begingroup$

                    I think Theorem 4.14 in Ric Wade's survey [1] should suffice. Ric also gives a discussion of where one can find other (older) proofs of the existence of a normal form for elements in RAAGs; I think he mentions Green's thesis [2] as the oldest source containing a proof.



                    [1] https://arxiv.org/pdf/1109.1722.pdf



                    [2] Elisabeth R. Green. Graph products of groups. PhD thesis, The University of Leeds, 1990.






                    share|cite|improve this answer









                    $endgroup$













                    • $begingroup$
                      Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                      $endgroup$
                      – AGenevois
                      Jan 5 at 6:45
















                    -1












                    $begingroup$

                    I think Theorem 4.14 in Ric Wade's survey [1] should suffice. Ric also gives a discussion of where one can find other (older) proofs of the existence of a normal form for elements in RAAGs; I think he mentions Green's thesis [2] as the oldest source containing a proof.



                    [1] https://arxiv.org/pdf/1109.1722.pdf



                    [2] Elisabeth R. Green. Graph products of groups. PhD thesis, The University of Leeds, 1990.






                    share|cite|improve this answer









                    $endgroup$













                    • $begingroup$
                      Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                      $endgroup$
                      – AGenevois
                      Jan 5 at 6:45














                    -1












                    -1








                    -1





                    $begingroup$

                    I think Theorem 4.14 in Ric Wade's survey [1] should suffice. Ric also gives a discussion of where one can find other (older) proofs of the existence of a normal form for elements in RAAGs; I think he mentions Green's thesis [2] as the oldest source containing a proof.



                    [1] https://arxiv.org/pdf/1109.1722.pdf



                    [2] Elisabeth R. Green. Graph products of groups. PhD thesis, The University of Leeds, 1990.






                    share|cite|improve this answer









                    $endgroup$



                    I think Theorem 4.14 in Ric Wade's survey [1] should suffice. Ric also gives a discussion of where one can find other (older) proofs of the existence of a normal form for elements in RAAGs; I think he mentions Green's thesis [2] as the oldest source containing a proof.



                    [1] https://arxiv.org/pdf/1109.1722.pdf



                    [2] Elisabeth R. Green. Graph products of groups. PhD thesis, The University of Leeds, 1990.







                    share|cite|improve this answer












                    share|cite|improve this answer



                    share|cite|improve this answer










                    answered Jan 4 at 9:14









                    Dawid KielakDawid Kielak

                    1295




                    1295












                    • $begingroup$
                      Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                      $endgroup$
                      – AGenevois
                      Jan 5 at 6:45


















                    • $begingroup$
                      Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                      $endgroup$
                      – AGenevois
                      Jan 5 at 6:45
















                    $begingroup$
                    Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                    $endgroup$
                    – AGenevois
                    Jan 5 at 6:45




                    $begingroup$
                    Thank you for your answer, but I think you are confusing the word problem with the conjugacy problem.
                    $endgroup$
                    – AGenevois
                    Jan 5 at 6:45


















                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to MathOverflow!


                    • 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%2fmathoverflow.net%2fquestions%2f319679%2fconjugacy-in-right-angled-artin-groups%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

                    Wiesbaden

                    Marschland

                    Dieringhausen