Wu formula for manifolds with boundaryWhat manifold has $mathbbHP^odd$ as a boundary?Measuring the failure of pushforward to commute with Steenrod squaresTopological invariance of Stiefel-Whitney classes for open smooth manifoldsWho discovered this definition of Stiefel-Whitney classes?Two set of axioms for Stiefel-Whitney classesDiscrete Pin structuresExample of a finite group $G$ with low dimensional cohomology not generated by Stiefel-Whitney classes of flat vector bundles over $BG$

Wu formula for manifolds with boundary


What manifold has $mathbbHP^odd$ as a boundary?Measuring the failure of pushforward to commute with Steenrod squaresTopological invariance of Stiefel-Whitney classes for open smooth manifoldsWho discovered this definition of Stiefel-Whitney classes?Two set of axioms for Stiefel-Whitney classesDiscrete Pin structuresExample of a finite group $G$ with low dimensional cohomology not generated by Stiefel-Whitney classes of flat vector bundles over $BG$













16












$begingroup$


The classical Wu formula claims that if $M$ is a smooth closed $n$-manifold with fundamental class $zin H_n(M;mathbbZ_2)$, then the total Stiefel-Whitney class $w(M)$ is equal to $Sq(v)$, where $v=sum v_iin H^*(M;mathbbZ_2)$ is the unique cohomology class such that
$$langle vcup x,zrangle=langle Sq(x),zrangle$$
for all $xin H^*(M;mathbbZ_2)$. Thus, for $kge0$, $v_kcup x=Sq^k(x)$ for all $xin H^n-k(M;mathbbZ_2)$, and
$$w_k(M)=sum_i+j=kSq^i(v_j).$$
Here the Poincare duality guarantees the existence and uniqueness of $v$.



My question: if $M$ is a smooth compact $n$-manifold with boundary, is there a similar Wu formula?
In this case, there is a fundamental class $zin H_n(M,partial M;mathbbZ_2)$ and the relative Poincare duality claims that capping with $z$ yields duality isomorphisms
$$D:H^p(M,partial M;mathbbZ_2)to H_n-p(M;mathbbZ_2)$$
and
$$D:H^p(M;mathbbZ_2)to H_n-p(M,partial M;mathbbZ_2).$$



Thank you!










share|cite|improve this question









$endgroup$


















    16












    $begingroup$


    The classical Wu formula claims that if $M$ is a smooth closed $n$-manifold with fundamental class $zin H_n(M;mathbbZ_2)$, then the total Stiefel-Whitney class $w(M)$ is equal to $Sq(v)$, where $v=sum v_iin H^*(M;mathbbZ_2)$ is the unique cohomology class such that
    $$langle vcup x,zrangle=langle Sq(x),zrangle$$
    for all $xin H^*(M;mathbbZ_2)$. Thus, for $kge0$, $v_kcup x=Sq^k(x)$ for all $xin H^n-k(M;mathbbZ_2)$, and
    $$w_k(M)=sum_i+j=kSq^i(v_j).$$
    Here the Poincare duality guarantees the existence and uniqueness of $v$.



    My question: if $M$ is a smooth compact $n$-manifold with boundary, is there a similar Wu formula?
    In this case, there is a fundamental class $zin H_n(M,partial M;mathbbZ_2)$ and the relative Poincare duality claims that capping with $z$ yields duality isomorphisms
    $$D:H^p(M,partial M;mathbbZ_2)to H_n-p(M;mathbbZ_2)$$
    and
    $$D:H^p(M;mathbbZ_2)to H_n-p(M,partial M;mathbbZ_2).$$



    Thank you!










    share|cite|improve this question









    $endgroup$
















      16












      16








      16


      2



      $begingroup$


      The classical Wu formula claims that if $M$ is a smooth closed $n$-manifold with fundamental class $zin H_n(M;mathbbZ_2)$, then the total Stiefel-Whitney class $w(M)$ is equal to $Sq(v)$, where $v=sum v_iin H^*(M;mathbbZ_2)$ is the unique cohomology class such that
      $$langle vcup x,zrangle=langle Sq(x),zrangle$$
      for all $xin H^*(M;mathbbZ_2)$. Thus, for $kge0$, $v_kcup x=Sq^k(x)$ for all $xin H^n-k(M;mathbbZ_2)$, and
      $$w_k(M)=sum_i+j=kSq^i(v_j).$$
      Here the Poincare duality guarantees the existence and uniqueness of $v$.



      My question: if $M$ is a smooth compact $n$-manifold with boundary, is there a similar Wu formula?
      In this case, there is a fundamental class $zin H_n(M,partial M;mathbbZ_2)$ and the relative Poincare duality claims that capping with $z$ yields duality isomorphisms
      $$D:H^p(M,partial M;mathbbZ_2)to H_n-p(M;mathbbZ_2)$$
      and
      $$D:H^p(M;mathbbZ_2)to H_n-p(M,partial M;mathbbZ_2).$$



      Thank you!










      share|cite|improve this question









      $endgroup$




      The classical Wu formula claims that if $M$ is a smooth closed $n$-manifold with fundamental class $zin H_n(M;mathbbZ_2)$, then the total Stiefel-Whitney class $w(M)$ is equal to $Sq(v)$, where $v=sum v_iin H^*(M;mathbbZ_2)$ is the unique cohomology class such that
      $$langle vcup x,zrangle=langle Sq(x),zrangle$$
      for all $xin H^*(M;mathbbZ_2)$. Thus, for $kge0$, $v_kcup x=Sq^k(x)$ for all $xin H^n-k(M;mathbbZ_2)$, and
      $$w_k(M)=sum_i+j=kSq^i(v_j).$$
      Here the Poincare duality guarantees the existence and uniqueness of $v$.



      My question: if $M$ is a smooth compact $n$-manifold with boundary, is there a similar Wu formula?
      In this case, there is a fundamental class $zin H_n(M,partial M;mathbbZ_2)$ and the relative Poincare duality claims that capping with $z$ yields duality isomorphisms
      $$D:H^p(M,partial M;mathbbZ_2)to H_n-p(M;mathbbZ_2)$$
      and
      $$D:H^p(M;mathbbZ_2)to H_n-p(M,partial M;mathbbZ_2).$$



      Thank you!







      at.algebraic-topology gt.geometric-topology cohomology smooth-manifolds characteristic-classes






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Apr 17 at 17:05









      BorromeanBorromean

      6253 silver badges12 bronze badges




      6253 silver badges12 bronze badges























          1 Answer
          1






          active

          oldest

          votes


















          15














          $begingroup$

          A relative Wu formula for manifolds with boundary is discussed in Section 7 of



          Kervaire, Michel A., Relative characteristic classes, Am. J. Math. 79, 517-558 (1957). ZBL0173.51201.



          In particular, there are relative Wu classes $U^qin H^q(M;mathbbZ/2)$ for $q=0,1,ldots , n$ defined by the property that
          $$
          Sq^q(x)=U^qcup x in H^n(M,partial M;mathbbZ/2)
          $$

          for all $xin H^n-q(M,partial M;mathbbZ/2)$. Kervaire deduces the relative Wu formula $w(M)=Sq(U)$ from the absolute Wu formula for the double $N=Mcup_partial M M$ (the closed manifold obtained by gluing two copies of $M$ along the identity map of $partial M$), using naturality with respect to the inclusion $i:Mhookrightarrow N$.






          share|cite|improve this answer









          $endgroup$
















            Your Answer








            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/4.0/"u003ecc by-sa 4.0 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%2f328306%2fwu-formula-for-manifolds-with-boundary%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









            15














            $begingroup$

            A relative Wu formula for manifolds with boundary is discussed in Section 7 of



            Kervaire, Michel A., Relative characteristic classes, Am. J. Math. 79, 517-558 (1957). ZBL0173.51201.



            In particular, there are relative Wu classes $U^qin H^q(M;mathbbZ/2)$ for $q=0,1,ldots , n$ defined by the property that
            $$
            Sq^q(x)=U^qcup x in H^n(M,partial M;mathbbZ/2)
            $$

            for all $xin H^n-q(M,partial M;mathbbZ/2)$. Kervaire deduces the relative Wu formula $w(M)=Sq(U)$ from the absolute Wu formula for the double $N=Mcup_partial M M$ (the closed manifold obtained by gluing two copies of $M$ along the identity map of $partial M$), using naturality with respect to the inclusion $i:Mhookrightarrow N$.






            share|cite|improve this answer









            $endgroup$



















              15














              $begingroup$

              A relative Wu formula for manifolds with boundary is discussed in Section 7 of



              Kervaire, Michel A., Relative characteristic classes, Am. J. Math. 79, 517-558 (1957). ZBL0173.51201.



              In particular, there are relative Wu classes $U^qin H^q(M;mathbbZ/2)$ for $q=0,1,ldots , n$ defined by the property that
              $$
              Sq^q(x)=U^qcup x in H^n(M,partial M;mathbbZ/2)
              $$

              for all $xin H^n-q(M,partial M;mathbbZ/2)$. Kervaire deduces the relative Wu formula $w(M)=Sq(U)$ from the absolute Wu formula for the double $N=Mcup_partial M M$ (the closed manifold obtained by gluing two copies of $M$ along the identity map of $partial M$), using naturality with respect to the inclusion $i:Mhookrightarrow N$.






              share|cite|improve this answer









              $endgroup$

















                15














                15










                15







                $begingroup$

                A relative Wu formula for manifolds with boundary is discussed in Section 7 of



                Kervaire, Michel A., Relative characteristic classes, Am. J. Math. 79, 517-558 (1957). ZBL0173.51201.



                In particular, there are relative Wu classes $U^qin H^q(M;mathbbZ/2)$ for $q=0,1,ldots , n$ defined by the property that
                $$
                Sq^q(x)=U^qcup x in H^n(M,partial M;mathbbZ/2)
                $$

                for all $xin H^n-q(M,partial M;mathbbZ/2)$. Kervaire deduces the relative Wu formula $w(M)=Sq(U)$ from the absolute Wu formula for the double $N=Mcup_partial M M$ (the closed manifold obtained by gluing two copies of $M$ along the identity map of $partial M$), using naturality with respect to the inclusion $i:Mhookrightarrow N$.






                share|cite|improve this answer









                $endgroup$



                A relative Wu formula for manifolds with boundary is discussed in Section 7 of



                Kervaire, Michel A., Relative characteristic classes, Am. J. Math. 79, 517-558 (1957). ZBL0173.51201.



                In particular, there are relative Wu classes $U^qin H^q(M;mathbbZ/2)$ for $q=0,1,ldots , n$ defined by the property that
                $$
                Sq^q(x)=U^qcup x in H^n(M,partial M;mathbbZ/2)
                $$

                for all $xin H^n-q(M,partial M;mathbbZ/2)$. Kervaire deduces the relative Wu formula $w(M)=Sq(U)$ from the absolute Wu formula for the double $N=Mcup_partial M M$ (the closed manifold obtained by gluing two copies of $M$ along the identity map of $partial M$), using naturality with respect to the inclusion $i:Mhookrightarrow N$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Apr 17 at 18:47









                Mark GrantMark Grant

                24.3k6 gold badges68 silver badges146 bronze badges




                24.3k6 gold badges68 silver badges146 bronze badges































                    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%2f328306%2fwu-formula-for-manifolds-with-boundary%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

                    Tamil (spriik) Luke uk diar | Nawigatjuun

                    Align equal signs while including text over equalitiesAMS align: left aligned text/math plus multicolumn alignmentMultiple alignmentsAligning equations in multiple placesNumbering and aligning an equation with multiple columnsHow to align one equation with another multline equationUsing \ in environments inside the begintabularxNumber equations and preserving alignment of equal signsHow can I align equations to the left and to the right?Double equation alignment problem within align enviromentAligned within align: Why are they right-aligned?

                    Where does the image of a data connector as a sharp metal spike originate from?Where does the concept of infected people turning into zombies only after death originate from?Where does the motif of a reanimated human head originate?Where did the notion that Dragons could speak originate?Where does the archetypal image of the 'Grey' alien come from?Where did the suffix '-Man' originate?Where does the notion of being injured or killed by an illusion originate?Where did the term “sophont” originate?Where does the trope of magic spells being driven by advanced technology originate from?Where did the term “the living impaired” originate?