Existence of Thom Class












0














In page 133, Theorem 8.5.5.




(The Thom isomoprhism theorem) Let $pi:V rightarrow X$ be a complex vector bundle of rank $n$, over al locally comapct space $X$. Let
$$ 0 rightarrow pi^* wedge ^0 V rightarrow pi^* wedge ^1 V rightarrow cdots rightarrow pi^* wedge ^n V rightarrow0 $$
we the chain complex, the map $pi^* wedge ^pV rightarrow pi^* wedge ^{p+1} V$ is given over $v in V$ by taking the exterior product with $v$. The Thom class $t_V in K_c(V)$ is the complex conjugate of the wrap of this complex. Then the map
$$ th^K:K_c(X) rightarrow K_c(V), : , x mapsto pi^*x # t_V $$
is an isomoprhism.




The remark says:




We do not need to know the Thom isomoprhism theorem, but only the existence of the Thom Class.




I'm confused with this statement. Is there something needed to prove for the existence?



I think what we have to prove is that $t_V$ is indeed an element of $K_c(V)$? How is this justified?










share|cite|improve this question





























    0














    In page 133, Theorem 8.5.5.




    (The Thom isomoprhism theorem) Let $pi:V rightarrow X$ be a complex vector bundle of rank $n$, over al locally comapct space $X$. Let
    $$ 0 rightarrow pi^* wedge ^0 V rightarrow pi^* wedge ^1 V rightarrow cdots rightarrow pi^* wedge ^n V rightarrow0 $$
    we the chain complex, the map $pi^* wedge ^pV rightarrow pi^* wedge ^{p+1} V$ is given over $v in V$ by taking the exterior product with $v$. The Thom class $t_V in K_c(V)$ is the complex conjugate of the wrap of this complex. Then the map
    $$ th^K:K_c(X) rightarrow K_c(V), : , x mapsto pi^*x # t_V $$
    is an isomoprhism.




    The remark says:




    We do not need to know the Thom isomoprhism theorem, but only the existence of the Thom Class.




    I'm confused with this statement. Is there something needed to prove for the existence?



    I think what we have to prove is that $t_V$ is indeed an element of $K_c(V)$? How is this justified?










    share|cite|improve this question



























      0












      0








      0







      In page 133, Theorem 8.5.5.




      (The Thom isomoprhism theorem) Let $pi:V rightarrow X$ be a complex vector bundle of rank $n$, over al locally comapct space $X$. Let
      $$ 0 rightarrow pi^* wedge ^0 V rightarrow pi^* wedge ^1 V rightarrow cdots rightarrow pi^* wedge ^n V rightarrow0 $$
      we the chain complex, the map $pi^* wedge ^pV rightarrow pi^* wedge ^{p+1} V$ is given over $v in V$ by taking the exterior product with $v$. The Thom class $t_V in K_c(V)$ is the complex conjugate of the wrap of this complex. Then the map
      $$ th^K:K_c(X) rightarrow K_c(V), : , x mapsto pi^*x # t_V $$
      is an isomoprhism.




      The remark says:




      We do not need to know the Thom isomoprhism theorem, but only the existence of the Thom Class.




      I'm confused with this statement. Is there something needed to prove for the existence?



      I think what we have to prove is that $t_V$ is indeed an element of $K_c(V)$? How is this justified?










      share|cite|improve this question















      In page 133, Theorem 8.5.5.




      (The Thom isomoprhism theorem) Let $pi:V rightarrow X$ be a complex vector bundle of rank $n$, over al locally comapct space $X$. Let
      $$ 0 rightarrow pi^* wedge ^0 V rightarrow pi^* wedge ^1 V rightarrow cdots rightarrow pi^* wedge ^n V rightarrow0 $$
      we the chain complex, the map $pi^* wedge ^pV rightarrow pi^* wedge ^{p+1} V$ is given over $v in V$ by taking the exterior product with $v$. The Thom class $t_V in K_c(V)$ is the complex conjugate of the wrap of this complex. Then the map
      $$ th^K:K_c(X) rightarrow K_c(V), : , x mapsto pi^*x # t_V $$
      is an isomoprhism.




      The remark says:




      We do not need to know the Thom isomoprhism theorem, but only the existence of the Thom Class.




      I'm confused with this statement. Is there something needed to prove for the existence?



      I think what we have to prove is that $t_V$ is indeed an element of $K_c(V)$? How is this justified?







      algebraic-topology vector-bundles k-theory topological-k-theory






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 19 '18 at 15:35

























      asked Dec 10 '18 at 1:56









      CL.

      2,1312822




      2,1312822



























          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%2f3033320%2fexistence-of-thom-class%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




















































          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.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • 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.


          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%2f3033320%2fexistence-of-thom-class%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

          Bressuire

          Cabo Verde

          Gyllenstierna