Restriction of Bruhat order to stabilizer of a vector











up vote
1
down vote

favorite
1












Let $W$ be a Weyl group (maybe better a Coxeter group, i.e. a group with action on vector space $V$ generated by reflections with some conditions). Consider $v in V$ be a vector. Let $text{Stab}_v subset W$ be a stabilizer of vector $v$.



Theorem
Group $text{Stab}_v$ is generated by reflections.



This Theorem is stated for example here, Theorem 1 (iii).
(in the case of Weyl group $text{Stab}_v$ is a Weyl group of Lie subgroup).



If we choose simple reflections in $W$ we will get a Bruhat order (I am interested in strong Bruhat order). Hence $text{Stab}_v$ is generated by reflections we can choose a set of simple reflections for $text{Stab}_v$; it gives as an interior Bruhat order on $text{Stab}_v$ (which a priori has nothing to do with the Bruhat order on whole $W$).




Is it true that for any choice of simple reflections in $W$ we can
find a set of simple reflections in $text{Stab}_v$ such that
restriction of Bruhat order from $W$ to $text{Stab}_v$ coincides with the
interior Bruhat order on $text{Stab}_v$?











share|cite|improve this question




























    up vote
    1
    down vote

    favorite
    1












    Let $W$ be a Weyl group (maybe better a Coxeter group, i.e. a group with action on vector space $V$ generated by reflections with some conditions). Consider $v in V$ be a vector. Let $text{Stab}_v subset W$ be a stabilizer of vector $v$.



    Theorem
    Group $text{Stab}_v$ is generated by reflections.



    This Theorem is stated for example here, Theorem 1 (iii).
    (in the case of Weyl group $text{Stab}_v$ is a Weyl group of Lie subgroup).



    If we choose simple reflections in $W$ we will get a Bruhat order (I am interested in strong Bruhat order). Hence $text{Stab}_v$ is generated by reflections we can choose a set of simple reflections for $text{Stab}_v$; it gives as an interior Bruhat order on $text{Stab}_v$ (which a priori has nothing to do with the Bruhat order on whole $W$).




    Is it true that for any choice of simple reflections in $W$ we can
    find a set of simple reflections in $text{Stab}_v$ such that
    restriction of Bruhat order from $W$ to $text{Stab}_v$ coincides with the
    interior Bruhat order on $text{Stab}_v$?











    share|cite|improve this question


























      up vote
      1
      down vote

      favorite
      1









      up vote
      1
      down vote

      favorite
      1






      1





      Let $W$ be a Weyl group (maybe better a Coxeter group, i.e. a group with action on vector space $V$ generated by reflections with some conditions). Consider $v in V$ be a vector. Let $text{Stab}_v subset W$ be a stabilizer of vector $v$.



      Theorem
      Group $text{Stab}_v$ is generated by reflections.



      This Theorem is stated for example here, Theorem 1 (iii).
      (in the case of Weyl group $text{Stab}_v$ is a Weyl group of Lie subgroup).



      If we choose simple reflections in $W$ we will get a Bruhat order (I am interested in strong Bruhat order). Hence $text{Stab}_v$ is generated by reflections we can choose a set of simple reflections for $text{Stab}_v$; it gives as an interior Bruhat order on $text{Stab}_v$ (which a priori has nothing to do with the Bruhat order on whole $W$).




      Is it true that for any choice of simple reflections in $W$ we can
      find a set of simple reflections in $text{Stab}_v$ such that
      restriction of Bruhat order from $W$ to $text{Stab}_v$ coincides with the
      interior Bruhat order on $text{Stab}_v$?











      share|cite|improve this question















      Let $W$ be a Weyl group (maybe better a Coxeter group, i.e. a group with action on vector space $V$ generated by reflections with some conditions). Consider $v in V$ be a vector. Let $text{Stab}_v subset W$ be a stabilizer of vector $v$.



      Theorem
      Group $text{Stab}_v$ is generated by reflections.



      This Theorem is stated for example here, Theorem 1 (iii).
      (in the case of Weyl group $text{Stab}_v$ is a Weyl group of Lie subgroup).



      If we choose simple reflections in $W$ we will get a Bruhat order (I am interested in strong Bruhat order). Hence $text{Stab}_v$ is generated by reflections we can choose a set of simple reflections for $text{Stab}_v$; it gives as an interior Bruhat order on $text{Stab}_v$ (which a priori has nothing to do with the Bruhat order on whole $W$).




      Is it true that for any choice of simple reflections in $W$ we can
      find a set of simple reflections in $text{Stab}_v$ such that
      restriction of Bruhat order from $W$ to $text{Stab}_v$ coincides with the
      interior Bruhat order on $text{Stab}_v$?








      combinatorics reflection root-systems coxeter-groups weyl-group






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Nov 13 at 5:20

























      asked Nov 12 at 16:33









      quinque

      1,445619




      1,445619



























          active

          oldest

          votes











          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',
          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%2f2995528%2frestriction-of-bruhat-order-to-stabilizer-of-a-vector%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown






























          active

          oldest

          votes













          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















           

          draft saved


          draft discarded



















































           


          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2995528%2frestriction-of-bruhat-order-to-stabilizer-of-a-vector%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

          How to change which sound is reproduced for terminal bell?

          Can I use Tabulator js library in my java Spring + Thymeleaf project?

          Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents