Complex jet structures












1












$begingroup$


In differential geometry/topology one can construct, given a function space (or fibre bundle), the jet space (or bundle) by considering the k-th order Taylor expansions.



Now I was wondering if something similar exists with respect to Laurent series for complex functions/sections?










share|cite|improve this question









$endgroup$

















    1












    $begingroup$


    In differential geometry/topology one can construct, given a function space (or fibre bundle), the jet space (or bundle) by considering the k-th order Taylor expansions.



    Now I was wondering if something similar exists with respect to Laurent series for complex functions/sections?










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      In differential geometry/topology one can construct, given a function space (or fibre bundle), the jet space (or bundle) by considering the k-th order Taylor expansions.



      Now I was wondering if something similar exists with respect to Laurent series for complex functions/sections?










      share|cite|improve this question









      $endgroup$




      In differential geometry/topology one can construct, given a function space (or fibre bundle), the jet space (or bundle) by considering the k-th order Taylor expansions.



      Now I was wondering if something similar exists with respect to Laurent series for complex functions/sections?







      complex-analysis differential-geometry






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 15 '18 at 21:53









      NDewolfNDewolf

      555210




      555210






















          1 Answer
          1






          active

          oldest

          votes


















          2












          $begingroup$

          If $M^{2m}$ and $N^{2n}$ are smooth manifolds, then the $k$-jet space $J^k(M, N)$ is an affine bundle over $M times N$ with fiber over $(x, y)$ being the space of $k$-order Taylor expansion of smooth functions (or rather, smooth germs) $f : U_x to V_y$ where $U_x$ and $V_y$ are local charts around $x$ and $y$ respectively. This is noncanonically isomorphic to the vector space $J^k(Bbb R^{2m}, Bbb R^{2n})$, or $k$-order Taylor polynomials of maps $Bbb R^{2m} to Bbb R^{2n}$ at the origin.



          Suppose $M$ and $N$ admit and has been specified individual complex structures. Then there is a subspace $mathscr{R}^k subset J^k(M, N)$ such that $mathscr{R}^k$ similarly fibers over $M times N$ with fibers being the subspace $J^k_c(Bbb C^m, Bbb C^n)$ of $J^k(Bbb R^{2m}, Bbb R^{2n})$ consisting of $k$-order Taylor polynomials of holomorphic functions $Bbb C^m to Bbb C^n$.



          Funnily enough, this space is not as huge as you think: the whole Taylor series of a holomorphic function is determined by it's $1$-jet. That is, if $f$ is germ of a holomorphic function $U_x subset M to V_y subset M$, which is equivalent to the "Cauchy-Riemann differential relation" $j^1 f in mathscr{R}^1$ (note here that $mathscr{R}^1$ is cut out by polynomial equations of the form $partial u_i/partial x_lambda = partial v_i/partial y_mu$ and $partial u_i/partial y_lambda = -partial v_i/partial x_mu$, i.e., the Cauchy-Riemann equations), then the $k$-jet prolongation $mathscr{R}^1 to mathscr{R}^k$ sending $j^1 f$ to $j^k f$ is a local parametrization for any $k$.



          On a different note, it's interesting to ask when this particular differential relation (or the "complex jet space" you wanted) admits an $h$-principle. Namely, the space of holomorphic maps $C^omega(M, N)$ are precisely base of holonomic sections $s : M to J^1(M, N)$ such that $s(M) subset mathscr{R}^1$. When is the inclusion $text{Hol}(mathscr{R}^1) to text{Sec}(mathscr{R}^1)$ of the space of holonomic (or integrable) sections into the full space of sections a homotopy equivalence? I believe this is true if $M$ is a Stein manifold which in $dim M = 2$ is equivalent to $M$ being a noncompact Riemann surface, and that seems to be the appropriate context for $h$-principles to hold (in general noncompactness in the domain is very necessary for any sort of $h$-principle to hold). Maybe experts can comment more on this.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
            $endgroup$
            – NDewolf
            Dec 16 '18 at 22:18






          • 1




            $begingroup$
            @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
            $endgroup$
            – Balarka Sen
            Dec 17 '18 at 0:08













          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%2f3042000%2fcomplex-jet-structures%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









          2












          $begingroup$

          If $M^{2m}$ and $N^{2n}$ are smooth manifolds, then the $k$-jet space $J^k(M, N)$ is an affine bundle over $M times N$ with fiber over $(x, y)$ being the space of $k$-order Taylor expansion of smooth functions (or rather, smooth germs) $f : U_x to V_y$ where $U_x$ and $V_y$ are local charts around $x$ and $y$ respectively. This is noncanonically isomorphic to the vector space $J^k(Bbb R^{2m}, Bbb R^{2n})$, or $k$-order Taylor polynomials of maps $Bbb R^{2m} to Bbb R^{2n}$ at the origin.



          Suppose $M$ and $N$ admit and has been specified individual complex structures. Then there is a subspace $mathscr{R}^k subset J^k(M, N)$ such that $mathscr{R}^k$ similarly fibers over $M times N$ with fibers being the subspace $J^k_c(Bbb C^m, Bbb C^n)$ of $J^k(Bbb R^{2m}, Bbb R^{2n})$ consisting of $k$-order Taylor polynomials of holomorphic functions $Bbb C^m to Bbb C^n$.



          Funnily enough, this space is not as huge as you think: the whole Taylor series of a holomorphic function is determined by it's $1$-jet. That is, if $f$ is germ of a holomorphic function $U_x subset M to V_y subset M$, which is equivalent to the "Cauchy-Riemann differential relation" $j^1 f in mathscr{R}^1$ (note here that $mathscr{R}^1$ is cut out by polynomial equations of the form $partial u_i/partial x_lambda = partial v_i/partial y_mu$ and $partial u_i/partial y_lambda = -partial v_i/partial x_mu$, i.e., the Cauchy-Riemann equations), then the $k$-jet prolongation $mathscr{R}^1 to mathscr{R}^k$ sending $j^1 f$ to $j^k f$ is a local parametrization for any $k$.



          On a different note, it's interesting to ask when this particular differential relation (or the "complex jet space" you wanted) admits an $h$-principle. Namely, the space of holomorphic maps $C^omega(M, N)$ are precisely base of holonomic sections $s : M to J^1(M, N)$ such that $s(M) subset mathscr{R}^1$. When is the inclusion $text{Hol}(mathscr{R}^1) to text{Sec}(mathscr{R}^1)$ of the space of holonomic (or integrable) sections into the full space of sections a homotopy equivalence? I believe this is true if $M$ is a Stein manifold which in $dim M = 2$ is equivalent to $M$ being a noncompact Riemann surface, and that seems to be the appropriate context for $h$-principles to hold (in general noncompactness in the domain is very necessary for any sort of $h$-principle to hold). Maybe experts can comment more on this.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
            $endgroup$
            – NDewolf
            Dec 16 '18 at 22:18






          • 1




            $begingroup$
            @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
            $endgroup$
            – Balarka Sen
            Dec 17 '18 at 0:08


















          2












          $begingroup$

          If $M^{2m}$ and $N^{2n}$ are smooth manifolds, then the $k$-jet space $J^k(M, N)$ is an affine bundle over $M times N$ with fiber over $(x, y)$ being the space of $k$-order Taylor expansion of smooth functions (or rather, smooth germs) $f : U_x to V_y$ where $U_x$ and $V_y$ are local charts around $x$ and $y$ respectively. This is noncanonically isomorphic to the vector space $J^k(Bbb R^{2m}, Bbb R^{2n})$, or $k$-order Taylor polynomials of maps $Bbb R^{2m} to Bbb R^{2n}$ at the origin.



          Suppose $M$ and $N$ admit and has been specified individual complex structures. Then there is a subspace $mathscr{R}^k subset J^k(M, N)$ such that $mathscr{R}^k$ similarly fibers over $M times N$ with fibers being the subspace $J^k_c(Bbb C^m, Bbb C^n)$ of $J^k(Bbb R^{2m}, Bbb R^{2n})$ consisting of $k$-order Taylor polynomials of holomorphic functions $Bbb C^m to Bbb C^n$.



          Funnily enough, this space is not as huge as you think: the whole Taylor series of a holomorphic function is determined by it's $1$-jet. That is, if $f$ is germ of a holomorphic function $U_x subset M to V_y subset M$, which is equivalent to the "Cauchy-Riemann differential relation" $j^1 f in mathscr{R}^1$ (note here that $mathscr{R}^1$ is cut out by polynomial equations of the form $partial u_i/partial x_lambda = partial v_i/partial y_mu$ and $partial u_i/partial y_lambda = -partial v_i/partial x_mu$, i.e., the Cauchy-Riemann equations), then the $k$-jet prolongation $mathscr{R}^1 to mathscr{R}^k$ sending $j^1 f$ to $j^k f$ is a local parametrization for any $k$.



          On a different note, it's interesting to ask when this particular differential relation (or the "complex jet space" you wanted) admits an $h$-principle. Namely, the space of holomorphic maps $C^omega(M, N)$ are precisely base of holonomic sections $s : M to J^1(M, N)$ such that $s(M) subset mathscr{R}^1$. When is the inclusion $text{Hol}(mathscr{R}^1) to text{Sec}(mathscr{R}^1)$ of the space of holonomic (or integrable) sections into the full space of sections a homotopy equivalence? I believe this is true if $M$ is a Stein manifold which in $dim M = 2$ is equivalent to $M$ being a noncompact Riemann surface, and that seems to be the appropriate context for $h$-principles to hold (in general noncompactness in the domain is very necessary for any sort of $h$-principle to hold). Maybe experts can comment more on this.






          share|cite|improve this answer











          $endgroup$













          • $begingroup$
            Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
            $endgroup$
            – NDewolf
            Dec 16 '18 at 22:18






          • 1




            $begingroup$
            @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
            $endgroup$
            – Balarka Sen
            Dec 17 '18 at 0:08
















          2












          2








          2





          $begingroup$

          If $M^{2m}$ and $N^{2n}$ are smooth manifolds, then the $k$-jet space $J^k(M, N)$ is an affine bundle over $M times N$ with fiber over $(x, y)$ being the space of $k$-order Taylor expansion of smooth functions (or rather, smooth germs) $f : U_x to V_y$ where $U_x$ and $V_y$ are local charts around $x$ and $y$ respectively. This is noncanonically isomorphic to the vector space $J^k(Bbb R^{2m}, Bbb R^{2n})$, or $k$-order Taylor polynomials of maps $Bbb R^{2m} to Bbb R^{2n}$ at the origin.



          Suppose $M$ and $N$ admit and has been specified individual complex structures. Then there is a subspace $mathscr{R}^k subset J^k(M, N)$ such that $mathscr{R}^k$ similarly fibers over $M times N$ with fibers being the subspace $J^k_c(Bbb C^m, Bbb C^n)$ of $J^k(Bbb R^{2m}, Bbb R^{2n})$ consisting of $k$-order Taylor polynomials of holomorphic functions $Bbb C^m to Bbb C^n$.



          Funnily enough, this space is not as huge as you think: the whole Taylor series of a holomorphic function is determined by it's $1$-jet. That is, if $f$ is germ of a holomorphic function $U_x subset M to V_y subset M$, which is equivalent to the "Cauchy-Riemann differential relation" $j^1 f in mathscr{R}^1$ (note here that $mathscr{R}^1$ is cut out by polynomial equations of the form $partial u_i/partial x_lambda = partial v_i/partial y_mu$ and $partial u_i/partial y_lambda = -partial v_i/partial x_mu$, i.e., the Cauchy-Riemann equations), then the $k$-jet prolongation $mathscr{R}^1 to mathscr{R}^k$ sending $j^1 f$ to $j^k f$ is a local parametrization for any $k$.



          On a different note, it's interesting to ask when this particular differential relation (or the "complex jet space" you wanted) admits an $h$-principle. Namely, the space of holomorphic maps $C^omega(M, N)$ are precisely base of holonomic sections $s : M to J^1(M, N)$ such that $s(M) subset mathscr{R}^1$. When is the inclusion $text{Hol}(mathscr{R}^1) to text{Sec}(mathscr{R}^1)$ of the space of holonomic (or integrable) sections into the full space of sections a homotopy equivalence? I believe this is true if $M$ is a Stein manifold which in $dim M = 2$ is equivalent to $M$ being a noncompact Riemann surface, and that seems to be the appropriate context for $h$-principles to hold (in general noncompactness in the domain is very necessary for any sort of $h$-principle to hold). Maybe experts can comment more on this.






          share|cite|improve this answer











          $endgroup$



          If $M^{2m}$ and $N^{2n}$ are smooth manifolds, then the $k$-jet space $J^k(M, N)$ is an affine bundle over $M times N$ with fiber over $(x, y)$ being the space of $k$-order Taylor expansion of smooth functions (or rather, smooth germs) $f : U_x to V_y$ where $U_x$ and $V_y$ are local charts around $x$ and $y$ respectively. This is noncanonically isomorphic to the vector space $J^k(Bbb R^{2m}, Bbb R^{2n})$, or $k$-order Taylor polynomials of maps $Bbb R^{2m} to Bbb R^{2n}$ at the origin.



          Suppose $M$ and $N$ admit and has been specified individual complex structures. Then there is a subspace $mathscr{R}^k subset J^k(M, N)$ such that $mathscr{R}^k$ similarly fibers over $M times N$ with fibers being the subspace $J^k_c(Bbb C^m, Bbb C^n)$ of $J^k(Bbb R^{2m}, Bbb R^{2n})$ consisting of $k$-order Taylor polynomials of holomorphic functions $Bbb C^m to Bbb C^n$.



          Funnily enough, this space is not as huge as you think: the whole Taylor series of a holomorphic function is determined by it's $1$-jet. That is, if $f$ is germ of a holomorphic function $U_x subset M to V_y subset M$, which is equivalent to the "Cauchy-Riemann differential relation" $j^1 f in mathscr{R}^1$ (note here that $mathscr{R}^1$ is cut out by polynomial equations of the form $partial u_i/partial x_lambda = partial v_i/partial y_mu$ and $partial u_i/partial y_lambda = -partial v_i/partial x_mu$, i.e., the Cauchy-Riemann equations), then the $k$-jet prolongation $mathscr{R}^1 to mathscr{R}^k$ sending $j^1 f$ to $j^k f$ is a local parametrization for any $k$.



          On a different note, it's interesting to ask when this particular differential relation (or the "complex jet space" you wanted) admits an $h$-principle. Namely, the space of holomorphic maps $C^omega(M, N)$ are precisely base of holonomic sections $s : M to J^1(M, N)$ such that $s(M) subset mathscr{R}^1$. When is the inclusion $text{Hol}(mathscr{R}^1) to text{Sec}(mathscr{R}^1)$ of the space of holonomic (or integrable) sections into the full space of sections a homotopy equivalence? I believe this is true if $M$ is a Stein manifold which in $dim M = 2$ is equivalent to $M$ being a noncompact Riemann surface, and that seems to be the appropriate context for $h$-principles to hold (in general noncompactness in the domain is very necessary for any sort of $h$-principle to hold). Maybe experts can comment more on this.







          share|cite|improve this answer














          share|cite|improve this answer



          share|cite|improve this answer








          edited Dec 17 '18 at 23:30

























          answered Dec 16 '18 at 0:39









          Balarka SenBalarka Sen

          10.2k13056




          10.2k13056












          • $begingroup$
            Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
            $endgroup$
            – NDewolf
            Dec 16 '18 at 22:18






          • 1




            $begingroup$
            @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
            $endgroup$
            – Balarka Sen
            Dec 17 '18 at 0:08




















          • $begingroup$
            Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
            $endgroup$
            – NDewolf
            Dec 16 '18 at 22:18






          • 1




            $begingroup$
            @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
            $endgroup$
            – Balarka Sen
            Dec 17 '18 at 0:08


















          $begingroup$
          Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
          $endgroup$
          – NDewolf
          Dec 16 '18 at 22:18




          $begingroup$
          Do you have some references for these theorems? I would like to learn more about this aspect of differential topology
          $endgroup$
          – NDewolf
          Dec 16 '18 at 22:18




          1




          1




          $begingroup$
          @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
          $endgroup$
          – Balarka Sen
          Dec 17 '18 at 0:08






          $begingroup$
          @NDewolf I learnt about the basic theory of jets and $h$-principles from Eliashberg-Mishachev, which I can recommend. There's also the classic book by Gromov, "Partial Differential Relations", but it's quite a hard read. I think he deals with various holomorphic $h$-principles in that book quite extensively, but I never got around to studying them properly. I wrote up a short exposition on the premise of $h$-principles for immersions here which you might find interesting.
          $endgroup$
          – Balarka Sen
          Dec 17 '18 at 0:08




















          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%2f3042000%2fcomplex-jet-structures%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

          Plaza Victoria

          In PowerPoint, is there a keyboard shortcut for bulleted / numbered list?

          How to put 3 figures in Latex with 2 figures side by side and 1 below these side by side images but in...