If $TM$ is trivial, then $Lambda^n(M)$ is also trivial and $M$ is orientable












0












$begingroup$


Suppose that $M$ is a smooth $n-$manifold. Suppose $$ TM=coprod_{pin M}T_pM $$ is the tangent bundle of $M$. And let $$ Lambda^n(M)=coprod_{pin M}Lambda^n(T_pM) $$ where $Lambda^n(T_pM)$ is alternating covariant $n-$tensor product. i.e.



$$Lambda^n(T_pM)=T^*_pMwedge T^*_pM wedge cdots wedge T^*_pM.$$



and



$$dim(Lambda^n(T_pM))=begin{bmatrix} dim(T_pM)\ n end{bmatrix}$$




If $TM$ is trivial, then $Lambda^n(M)$ is also trivial and $M$ is orientable.




I am trying to understand but seems difficult. I would be very appreciate any help. Thanks in advance.










share|cite|improve this question











$endgroup$

















    0












    $begingroup$


    Suppose that $M$ is a smooth $n-$manifold. Suppose $$ TM=coprod_{pin M}T_pM $$ is the tangent bundle of $M$. And let $$ Lambda^n(M)=coprod_{pin M}Lambda^n(T_pM) $$ where $Lambda^n(T_pM)$ is alternating covariant $n-$tensor product. i.e.



    $$Lambda^n(T_pM)=T^*_pMwedge T^*_pM wedge cdots wedge T^*_pM.$$



    and



    $$dim(Lambda^n(T_pM))=begin{bmatrix} dim(T_pM)\ n end{bmatrix}$$




    If $TM$ is trivial, then $Lambda^n(M)$ is also trivial and $M$ is orientable.




    I am trying to understand but seems difficult. I would be very appreciate any help. Thanks in advance.










    share|cite|improve this question











    $endgroup$















      0












      0








      0





      $begingroup$


      Suppose that $M$ is a smooth $n-$manifold. Suppose $$ TM=coprod_{pin M}T_pM $$ is the tangent bundle of $M$. And let $$ Lambda^n(M)=coprod_{pin M}Lambda^n(T_pM) $$ where $Lambda^n(T_pM)$ is alternating covariant $n-$tensor product. i.e.



      $$Lambda^n(T_pM)=T^*_pMwedge T^*_pM wedge cdots wedge T^*_pM.$$



      and



      $$dim(Lambda^n(T_pM))=begin{bmatrix} dim(T_pM)\ n end{bmatrix}$$




      If $TM$ is trivial, then $Lambda^n(M)$ is also trivial and $M$ is orientable.




      I am trying to understand but seems difficult. I would be very appreciate any help. Thanks in advance.










      share|cite|improve this question











      $endgroup$




      Suppose that $M$ is a smooth $n-$manifold. Suppose $$ TM=coprod_{pin M}T_pM $$ is the tangent bundle of $M$. And let $$ Lambda^n(M)=coprod_{pin M}Lambda^n(T_pM) $$ where $Lambda^n(T_pM)$ is alternating covariant $n-$tensor product. i.e.



      $$Lambda^n(T_pM)=T^*_pMwedge T^*_pM wedge cdots wedge T^*_pM.$$



      and



      $$dim(Lambda^n(T_pM))=begin{bmatrix} dim(T_pM)\ n end{bmatrix}$$




      If $TM$ is trivial, then $Lambda^n(M)$ is also trivial and $M$ is orientable.




      I am trying to understand but seems difficult. I would be very appreciate any help. Thanks in advance.







      orientation tangent-bundle






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 3 '18 at 14:00







      Lev Ban

















      asked Nov 30 '18 at 16:52









      Lev BanLev Ban

      1,0701317




      1,0701317






















          1 Answer
          1






          active

          oldest

          votes


















          1












          $begingroup$

          If $M$ is $n$-dimensional, $TM$ is trivial is equivalent to saying that there exists $n$-vector fields $X_1,...,X_n$ such that for every $xin M$, $X_i(x)neq 0$. Take a differentiable metric on $M$ and define the $1$-form $f_i(x)(u)=langle X_i(x),urangle$ where $uin T_xM$, $Lambda^n(M)_x$ is generated by $f_1(x)wedge...wedge f_n(x)$ which is also a volume form on $M$. This implies that $M$ is orientable.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
            $endgroup$
            – Lev Ban
            Nov 30 '18 at 17:09










          • $begingroup$
            because it is a dim 1 and you have the volume form
            $endgroup$
            – Tsemo Aristide
            Nov 30 '18 at 17:21











          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%2f3020313%2fif-tm-is-trivial-then-lambdanm-is-also-trivial-and-m-is-orientable%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












          $begingroup$

          If $M$ is $n$-dimensional, $TM$ is trivial is equivalent to saying that there exists $n$-vector fields $X_1,...,X_n$ such that for every $xin M$, $X_i(x)neq 0$. Take a differentiable metric on $M$ and define the $1$-form $f_i(x)(u)=langle X_i(x),urangle$ where $uin T_xM$, $Lambda^n(M)_x$ is generated by $f_1(x)wedge...wedge f_n(x)$ which is also a volume form on $M$. This implies that $M$ is orientable.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
            $endgroup$
            – Lev Ban
            Nov 30 '18 at 17:09










          • $begingroup$
            because it is a dim 1 and you have the volume form
            $endgroup$
            – Tsemo Aristide
            Nov 30 '18 at 17:21
















          1












          $begingroup$

          If $M$ is $n$-dimensional, $TM$ is trivial is equivalent to saying that there exists $n$-vector fields $X_1,...,X_n$ such that for every $xin M$, $X_i(x)neq 0$. Take a differentiable metric on $M$ and define the $1$-form $f_i(x)(u)=langle X_i(x),urangle$ where $uin T_xM$, $Lambda^n(M)_x$ is generated by $f_1(x)wedge...wedge f_n(x)$ which is also a volume form on $M$. This implies that $M$ is orientable.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
            $endgroup$
            – Lev Ban
            Nov 30 '18 at 17:09










          • $begingroup$
            because it is a dim 1 and you have the volume form
            $endgroup$
            – Tsemo Aristide
            Nov 30 '18 at 17:21














          1












          1








          1





          $begingroup$

          If $M$ is $n$-dimensional, $TM$ is trivial is equivalent to saying that there exists $n$-vector fields $X_1,...,X_n$ such that for every $xin M$, $X_i(x)neq 0$. Take a differentiable metric on $M$ and define the $1$-form $f_i(x)(u)=langle X_i(x),urangle$ where $uin T_xM$, $Lambda^n(M)_x$ is generated by $f_1(x)wedge...wedge f_n(x)$ which is also a volume form on $M$. This implies that $M$ is orientable.






          share|cite|improve this answer









          $endgroup$



          If $M$ is $n$-dimensional, $TM$ is trivial is equivalent to saying that there exists $n$-vector fields $X_1,...,X_n$ such that for every $xin M$, $X_i(x)neq 0$. Take a differentiable metric on $M$ and define the $1$-form $f_i(x)(u)=langle X_i(x),urangle$ where $uin T_xM$, $Lambda^n(M)_x$ is generated by $f_1(x)wedge...wedge f_n(x)$ which is also a volume form on $M$. This implies that $M$ is orientable.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Nov 30 '18 at 17:01









          Tsemo AristideTsemo Aristide

          58k11445




          58k11445












          • $begingroup$
            Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
            $endgroup$
            – Lev Ban
            Nov 30 '18 at 17:09










          • $begingroup$
            because it is a dim 1 and you have the volume form
            $endgroup$
            – Tsemo Aristide
            Nov 30 '18 at 17:21


















          • $begingroup$
            Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
            $endgroup$
            – Lev Ban
            Nov 30 '18 at 17:09










          • $begingroup$
            because it is a dim 1 and you have the volume form
            $endgroup$
            – Tsemo Aristide
            Nov 30 '18 at 17:21
















          $begingroup$
          Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
          $endgroup$
          – Lev Ban
          Nov 30 '18 at 17:09




          $begingroup$
          Thank you for your answer. But could you let me know why $Lambda^n(M)$ is also trivial?
          $endgroup$
          – Lev Ban
          Nov 30 '18 at 17:09












          $begingroup$
          because it is a dim 1 and you have the volume form
          $endgroup$
          – Tsemo Aristide
          Nov 30 '18 at 17:21




          $begingroup$
          because it is a dim 1 and you have the volume form
          $endgroup$
          – Tsemo Aristide
          Nov 30 '18 at 17:21


















          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%2f3020313%2fif-tm-is-trivial-then-lambdanm-is-also-trivial-and-m-is-orientable%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

          Biblatex bibliography style without URLs when DOI exists (in Overleaf with Zotero bibliography)

          ComboBox Display Member on multiple fields

          Is it possible to collect Nectar points via Trainline?