General distributional solution of the Airy Equation












2












$begingroup$


How can I prove that the Airy equation
$$ frac{d^2u}{dx^2}-xu = 0 $$
has at least two linear independent solutions?enter image description here



Once I've found it how can I prove the existence of two independent DISTRIBUTIONAL solutions










share|cite|improve this question











$endgroup$



migrated from physics.stackexchange.com Jan 6 at 19:37


This question came from our site for active researchers, academics and students of physics.























    2












    $begingroup$


    How can I prove that the Airy equation
    $$ frac{d^2u}{dx^2}-xu = 0 $$
    has at least two linear independent solutions?enter image description here



    Once I've found it how can I prove the existence of two independent DISTRIBUTIONAL solutions










    share|cite|improve this question











    $endgroup$



    migrated from physics.stackexchange.com Jan 6 at 19:37


    This question came from our site for active researchers, academics and students of physics.





















      2












      2








      2





      $begingroup$


      How can I prove that the Airy equation
      $$ frac{d^2u}{dx^2}-xu = 0 $$
      has at least two linear independent solutions?enter image description here



      Once I've found it how can I prove the existence of two independent DISTRIBUTIONAL solutions










      share|cite|improve this question











      $endgroup$




      How can I prove that the Airy equation
      $$ frac{d^2u}{dx^2}-xu = 0 $$
      has at least two linear independent solutions?enter image description here



      Once I've found it how can I prove the existence of two independent DISTRIBUTIONAL solutions







      ordinary-differential-equations






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 6 at 20:29







      MargeA

















      asked Jan 6 at 18:41









      MargeAMargeA

      162




      162




      migrated from physics.stackexchange.com Jan 6 at 19:37


      This question came from our site for active researchers, academics and students of physics.









      migrated from physics.stackexchange.com Jan 6 at 19:37


      This question came from our site for active researchers, academics and students of physics.
























          1 Answer
          1






          active

          oldest

          votes


















          1












          $begingroup$

          There is nothing special about the Airy equation. It is second-order linear equation. All such equations have two linearly independent solutions. Any book on differential equations will prove this.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Even if it is a distribution?
            $endgroup$
            – MargeA
            Jan 6 at 19:02










          • $begingroup$
            The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
            $endgroup$
            – mike stone
            Jan 6 at 19:05










          • $begingroup$
            I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
            $endgroup$
            – MargeA
            Jan 6 at 19:07










          • $begingroup$
            @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
            $endgroup$
            – LutzL
            Jan 6 at 19:42






          • 1




            $begingroup$
            You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
            $endgroup$
            – mike stone
            Jan 6 at 20:47












          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%2f3064316%2fgeneral-distributional-solution-of-the-airy-equation%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









          1












          $begingroup$

          There is nothing special about the Airy equation. It is second-order linear equation. All such equations have two linearly independent solutions. Any book on differential equations will prove this.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Even if it is a distribution?
            $endgroup$
            – MargeA
            Jan 6 at 19:02










          • $begingroup$
            The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
            $endgroup$
            – mike stone
            Jan 6 at 19:05










          • $begingroup$
            I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
            $endgroup$
            – MargeA
            Jan 6 at 19:07










          • $begingroup$
            @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
            $endgroup$
            – LutzL
            Jan 6 at 19:42






          • 1




            $begingroup$
            You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
            $endgroup$
            – mike stone
            Jan 6 at 20:47
















          1












          $begingroup$

          There is nothing special about the Airy equation. It is second-order linear equation. All such equations have two linearly independent solutions. Any book on differential equations will prove this.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Even if it is a distribution?
            $endgroup$
            – MargeA
            Jan 6 at 19:02










          • $begingroup$
            The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
            $endgroup$
            – mike stone
            Jan 6 at 19:05










          • $begingroup$
            I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
            $endgroup$
            – MargeA
            Jan 6 at 19:07










          • $begingroup$
            @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
            $endgroup$
            – LutzL
            Jan 6 at 19:42






          • 1




            $begingroup$
            You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
            $endgroup$
            – mike stone
            Jan 6 at 20:47














          1












          1








          1





          $begingroup$

          There is nothing special about the Airy equation. It is second-order linear equation. All such equations have two linearly independent solutions. Any book on differential equations will prove this.






          share|cite|improve this answer









          $endgroup$



          There is nothing special about the Airy equation. It is second-order linear equation. All such equations have two linearly independent solutions. Any book on differential equations will prove this.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Jan 6 at 19:00









          mike stonemike stone

          34317




          34317












          • $begingroup$
            Even if it is a distribution?
            $endgroup$
            – MargeA
            Jan 6 at 19:02










          • $begingroup$
            The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
            $endgroup$
            – mike stone
            Jan 6 at 19:05










          • $begingroup$
            I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
            $endgroup$
            – MargeA
            Jan 6 at 19:07










          • $begingroup$
            @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
            $endgroup$
            – LutzL
            Jan 6 at 19:42






          • 1




            $begingroup$
            You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
            $endgroup$
            – mike stone
            Jan 6 at 20:47


















          • $begingroup$
            Even if it is a distribution?
            $endgroup$
            – MargeA
            Jan 6 at 19:02










          • $begingroup$
            The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
            $endgroup$
            – mike stone
            Jan 6 at 19:05










          • $begingroup$
            I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
            $endgroup$
            – MargeA
            Jan 6 at 19:07










          • $begingroup$
            @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
            $endgroup$
            – LutzL
            Jan 6 at 19:42






          • 1




            $begingroup$
            You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
            $endgroup$
            – mike stone
            Jan 6 at 20:47
















          $begingroup$
          Even if it is a distribution?
          $endgroup$
          – MargeA
          Jan 6 at 19:02




          $begingroup$
          Even if it is a distribution?
          $endgroup$
          – MargeA
          Jan 6 at 19:02












          $begingroup$
          The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
          $endgroup$
          – mike stone
          Jan 6 at 19:05




          $begingroup$
          The two solutions are nice smooth -- even analytic --- functions. They can be regarded as distributions of course, but I feel that I am not understanding what it is that you are worried about . Why do distributionbs come into this? Are you perhaps thinking of them as some non-normalizable "eigenfunctions" of Schroedinger equation? Such generalized eigenfunctions can be thought of as distributions in a rigged Hilbert space.
          $endgroup$
          – mike stone
          Jan 6 at 19:05












          $begingroup$
          I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
          $endgroup$
          – MargeA
          Jan 6 at 19:07




          $begingroup$
          I asked about distributional solutions of the Airy equation. I found the solution thanks to the fourier transform, but I am not sure how to demonstrate that there are at least two independent solutions
          $endgroup$
          – MargeA
          Jan 6 at 19:07












          $begingroup$
          @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
          $endgroup$
          – LutzL
          Jan 6 at 19:42




          $begingroup$
          @MargeA : Then please demonstrate this solution process (edit the question text) and highlight the point where you are uncertain about the existence of two basis solutions.
          $endgroup$
          – LutzL
          Jan 6 at 19:42




          1




          1




          $begingroup$
          You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
          $endgroup$
          – mike stone
          Jan 6 at 20:47




          $begingroup$
          You get two linear independent solutions by replacing your integral's limits of $pm infty$ contours that run between any pair of the points $infty, e^{2pi i/3} infty, e^{-2pi i/3}infty$. The sum of all three contours is zero because the integrand is an entire function. I don't think that there are any singular distributional solutions in the weak sense of the equation.
          $endgroup$
          – mike stone
          Jan 6 at 20:47


















          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%2f3064316%2fgeneral-distributional-solution-of-the-airy-equation%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

          Wiesbaden

          Marschland

          Dieringhausen