Boundary of convex subset diffeomorphic to the sphere












2












$begingroup$


Suppose you have a strictly convex set $Omega subset mathbb{R}^n$, $n geq 0$, bounded, with non-empty interior. Without loss of generality I will assume $0 in text{Int} Omega$. Thus there exists a clear homeomorphism $x to frac{x}{|x|}$ between the boundary of $Omega$ and the sphere.



Seems to me that this map is actually a $C^1$-diffeomorphism, is it true without further assumption ? What if we also assume the boundary of $Omega$ to be $C^1$ ?










share|cite|improve this question









$endgroup$

















    2












    $begingroup$


    Suppose you have a strictly convex set $Omega subset mathbb{R}^n$, $n geq 0$, bounded, with non-empty interior. Without loss of generality I will assume $0 in text{Int} Omega$. Thus there exists a clear homeomorphism $x to frac{x}{|x|}$ between the boundary of $Omega$ and the sphere.



    Seems to me that this map is actually a $C^1$-diffeomorphism, is it true without further assumption ? What if we also assume the boundary of $Omega$ to be $C^1$ ?










    share|cite|improve this question









    $endgroup$















      2












      2








      2





      $begingroup$


      Suppose you have a strictly convex set $Omega subset mathbb{R}^n$, $n geq 0$, bounded, with non-empty interior. Without loss of generality I will assume $0 in text{Int} Omega$. Thus there exists a clear homeomorphism $x to frac{x}{|x|}$ between the boundary of $Omega$ and the sphere.



      Seems to me that this map is actually a $C^1$-diffeomorphism, is it true without further assumption ? What if we also assume the boundary of $Omega$ to be $C^1$ ?










      share|cite|improve this question









      $endgroup$




      Suppose you have a strictly convex set $Omega subset mathbb{R}^n$, $n geq 0$, bounded, with non-empty interior. Without loss of generality I will assume $0 in text{Int} Omega$. Thus there exists a clear homeomorphism $x to frac{x}{|x|}$ between the boundary of $Omega$ and the sphere.



      Seems to me that this map is actually a $C^1$-diffeomorphism, is it true without further assumption ? What if we also assume the boundary of $Omega$ to be $C^1$ ?







      differential-geometry convex-analysis






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Jan 10 at 10:34









      Gâteau-GalloisGâteau-Gallois

      362112




      362112






















          0






          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',
          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%2f3068482%2fboundary-of-convex-subset-diffeomorphic-to-the-sphere%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          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%2f3068482%2fboundary-of-convex-subset-diffeomorphic-to-the-sphere%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

          android studio warns about leanback feature tag usage required on manifest while using Unity exported app?

          SQL update select statement

          WPF add header to Image with URL pettitions [duplicate]