Two Bijective Holomorphic Functions

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite












Let $f,g : mathbbE to mathbbE$ be bijective, holomorphic functions with $f(0) = g(0)$ and $f'(0) = g'(0)$. Also, $f'$ and $g'$ don't have zeros.
Prove $f(z) = g(z)$ for all $z in mathbbE$. (Note: $mathbbE := B_1(0)$.)



It seemed like an easy problem but somehow I can't find an argument for this statement. I guess bijectivity is the hard part of this problem.







share|cite|improve this question























    up vote
    1
    down vote

    favorite












    Let $f,g : mathbbE to mathbbE$ be bijective, holomorphic functions with $f(0) = g(0)$ and $f'(0) = g'(0)$. Also, $f'$ and $g'$ don't have zeros.
    Prove $f(z) = g(z)$ for all $z in mathbbE$. (Note: $mathbbE := B_1(0)$.)



    It seemed like an easy problem but somehow I can't find an argument for this statement. I guess bijectivity is the hard part of this problem.







    share|cite|improve this question





















      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      Let $f,g : mathbbE to mathbbE$ be bijective, holomorphic functions with $f(0) = g(0)$ and $f'(0) = g'(0)$. Also, $f'$ and $g'$ don't have zeros.
      Prove $f(z) = g(z)$ for all $z in mathbbE$. (Note: $mathbbE := B_1(0)$.)



      It seemed like an easy problem but somehow I can't find an argument for this statement. I guess bijectivity is the hard part of this problem.







      share|cite|improve this question











      Let $f,g : mathbbE to mathbbE$ be bijective, holomorphic functions with $f(0) = g(0)$ and $f'(0) = g'(0)$. Also, $f'$ and $g'$ don't have zeros.
      Prove $f(z) = g(z)$ for all $z in mathbbE$. (Note: $mathbbE := B_1(0)$.)



      It seemed like an easy problem but somehow I can't find an argument for this statement. I guess bijectivity is the hard part of this problem.









      share|cite|improve this question










      share|cite|improve this question




      share|cite|improve this question









      asked Jul 14 at 22:53









      Kezer

      1,135316




      1,135316




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          1
          down vote



          accepted










          Since these functions are bijective and holomorphic, they are also biholomorphic. Define $h(z) = f^-1circ g(z)$. We have $h$ is a biholomorphism of the disk, $h(0) = 0$ and $h'(0) = 1$. By the Schwarz lemma we conclude $h(z)=z$.






          share|cite|improve this answer



















          • 2




            Karl Hermann Amandus Schwarz, not Schwartz :)
            – Martin R
            Jul 14 at 23:02











          • Thank you! I corrected it.
            – Hugocito
            Jul 14 at 23:03










          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',
          convertImagesToLinks: true,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          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%2f2852026%2ftwo-bijective-holomorphic-functions%23new-answer', 'question_page');

          );

          Post as a guest






























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          1
          down vote



          accepted










          Since these functions are bijective and holomorphic, they are also biholomorphic. Define $h(z) = f^-1circ g(z)$. We have $h$ is a biholomorphism of the disk, $h(0) = 0$ and $h'(0) = 1$. By the Schwarz lemma we conclude $h(z)=z$.






          share|cite|improve this answer



















          • 2




            Karl Hermann Amandus Schwarz, not Schwartz :)
            – Martin R
            Jul 14 at 23:02











          • Thank you! I corrected it.
            – Hugocito
            Jul 14 at 23:03














          up vote
          1
          down vote



          accepted










          Since these functions are bijective and holomorphic, they are also biholomorphic. Define $h(z) = f^-1circ g(z)$. We have $h$ is a biholomorphism of the disk, $h(0) = 0$ and $h'(0) = 1$. By the Schwarz lemma we conclude $h(z)=z$.






          share|cite|improve this answer



















          • 2




            Karl Hermann Amandus Schwarz, not Schwartz :)
            – Martin R
            Jul 14 at 23:02











          • Thank you! I corrected it.
            – Hugocito
            Jul 14 at 23:03












          up vote
          1
          down vote



          accepted







          up vote
          1
          down vote



          accepted






          Since these functions are bijective and holomorphic, they are also biholomorphic. Define $h(z) = f^-1circ g(z)$. We have $h$ is a biholomorphism of the disk, $h(0) = 0$ and $h'(0) = 1$. By the Schwarz lemma we conclude $h(z)=z$.






          share|cite|improve this answer















          Since these functions are bijective and holomorphic, they are also biholomorphic. Define $h(z) = f^-1circ g(z)$. We have $h$ is a biholomorphism of the disk, $h(0) = 0$ and $h'(0) = 1$. By the Schwarz lemma we conclude $h(z)=z$.







          share|cite|improve this answer















          share|cite|improve this answer



          share|cite|improve this answer








          edited Jul 14 at 23:03


























          answered Jul 14 at 23:01









          Hugocito

          1,6451019




          1,6451019







          • 2




            Karl Hermann Amandus Schwarz, not Schwartz :)
            – Martin R
            Jul 14 at 23:02











          • Thank you! I corrected it.
            – Hugocito
            Jul 14 at 23:03












          • 2




            Karl Hermann Amandus Schwarz, not Schwartz :)
            – Martin R
            Jul 14 at 23:02











          • Thank you! I corrected it.
            – Hugocito
            Jul 14 at 23:03







          2




          2




          Karl Hermann Amandus Schwarz, not Schwartz :)
          – Martin R
          Jul 14 at 23:02





          Karl Hermann Amandus Schwarz, not Schwartz :)
          – Martin R
          Jul 14 at 23:02













          Thank you! I corrected it.
          – Hugocito
          Jul 14 at 23:03




          Thank you! I corrected it.
          – Hugocito
          Jul 14 at 23:03












           

          draft saved


          draft discarded


























           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2852026%2ftwo-bijective-holomorphic-functions%23new-answer', 'question_page');

          );

          Post as a guest













































































          Comments

          Popular posts from this blog

          Color the edges and diagonals of a regular polygon

          Relationship between determinant of matrix and determinant of adjoint?

          What is the equation of a 3D cone with generalised tilt?