Rational maps induced by natural transformations












0














I am reading the paper Function Spaces and Continuos Algebraic Pairings for Varieties of Friedlander and Walker. More precisely, I am working on the following result.



enter image description here



In the proof of the proposition the authors claim that a natural transformation as above determines a rational map by sending a generic point $etacolon mathsf{Spec} , Flongrightarrow X$ to $Phi_f(eta)colonmathsf{Spec} , Flongrightarrow Y$. This passage is clear, indeed there is bijective correspondence between the rational maps from $X$ to $Y$ and morphisms
from $mathsf{Spec} , F $ to $Y$.



What I would to know is if the same thing holds true in the setup of classical quasi-projective varaieties, that is, open subsets of zero loci (in some projective space) of homogeneous polynomials. Of course in this case one cannot use the same argumet as above, because we don't have generic points. Any idea?










share|cite|improve this question



























    0














    I am reading the paper Function Spaces and Continuos Algebraic Pairings for Varieties of Friedlander and Walker. More precisely, I am working on the following result.



    enter image description here



    In the proof of the proposition the authors claim that a natural transformation as above determines a rational map by sending a generic point $etacolon mathsf{Spec} , Flongrightarrow X$ to $Phi_f(eta)colonmathsf{Spec} , Flongrightarrow Y$. This passage is clear, indeed there is bijective correspondence between the rational maps from $X$ to $Y$ and morphisms
    from $mathsf{Spec} , F $ to $Y$.



    What I would to know is if the same thing holds true in the setup of classical quasi-projective varaieties, that is, open subsets of zero loci (in some projective space) of homogeneous polynomials. Of course in this case one cannot use the same argumet as above, because we don't have generic points. Any idea?










    share|cite|improve this question

























      0












      0








      0







      I am reading the paper Function Spaces and Continuos Algebraic Pairings for Varieties of Friedlander and Walker. More precisely, I am working on the following result.



      enter image description here



      In the proof of the proposition the authors claim that a natural transformation as above determines a rational map by sending a generic point $etacolon mathsf{Spec} , Flongrightarrow X$ to $Phi_f(eta)colonmathsf{Spec} , Flongrightarrow Y$. This passage is clear, indeed there is bijective correspondence between the rational maps from $X$ to $Y$ and morphisms
      from $mathsf{Spec} , F $ to $Y$.



      What I would to know is if the same thing holds true in the setup of classical quasi-projective varaieties, that is, open subsets of zero loci (in some projective space) of homogeneous polynomials. Of course in this case one cannot use the same argumet as above, because we don't have generic points. Any idea?










      share|cite|improve this question













      I am reading the paper Function Spaces and Continuos Algebraic Pairings for Varieties of Friedlander and Walker. More precisely, I am working on the following result.



      enter image description here



      In the proof of the proposition the authors claim that a natural transformation as above determines a rational map by sending a generic point $etacolon mathsf{Spec} , Flongrightarrow X$ to $Phi_f(eta)colonmathsf{Spec} , Flongrightarrow Y$. This passage is clear, indeed there is bijective correspondence between the rational maps from $X$ to $Y$ and morphisms
      from $mathsf{Spec} , F $ to $Y$.



      What I would to know is if the same thing holds true in the setup of classical quasi-projective varaieties, that is, open subsets of zero loci (in some projective space) of homogeneous polynomials. Of course in this case one cannot use the same argumet as above, because we don't have generic points. Any idea?







      algebraic-geometry






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 29 '18 at 1:31









      Vincenzo ZaccaroVincenzo Zaccaro

      1,239719




      1,239719






















          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%2f3018024%2frational-maps-induced-by-natural-transformations%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.





          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%2f3018024%2frational-maps-induced-by-natural-transformations%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

          Quarter-circle Tiles

          build a pushdown automaton that recognizes the reverse language of a given pushdown automaton?

          Mont Emei