Integral of product of Hermite functions over finite interval











up vote
0
down vote

favorite












I am working with the Hermite functions $h_n(x)$ such that $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}.$ So, if $mneq n$, we know that the integral $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}=0$, but I am interested in understanding the behavior of this integral over a finite interval. More precisely if I fix $[-a,a]subset mathbb{R}$, and look at the integral $$I_n:=int_{-sqrt{n}a}^{sqrt{n}b}h_n(x)h_{n+1}(x)e^{-x^2/2}dx,$$
It's clear that $I_nto 0$, but can we say something about the rate at which it goes to 0? I guess that $I_n=O(n^{-2}),$ but I could not find any result in this direction.
One can of course ask for many more generalizations but this is something which I need to use in an estimate I am trying to prove.
Any help shall be highly appreciated.










share|cite|improve this question


























    up vote
    0
    down vote

    favorite












    I am working with the Hermite functions $h_n(x)$ such that $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}.$ So, if $mneq n$, we know that the integral $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}=0$, but I am interested in understanding the behavior of this integral over a finite interval. More precisely if I fix $[-a,a]subset mathbb{R}$, and look at the integral $$I_n:=int_{-sqrt{n}a}^{sqrt{n}b}h_n(x)h_{n+1}(x)e^{-x^2/2}dx,$$
    It's clear that $I_nto 0$, but can we say something about the rate at which it goes to 0? I guess that $I_n=O(n^{-2}),$ but I could not find any result in this direction.
    One can of course ask for many more generalizations but this is something which I need to use in an estimate I am trying to prove.
    Any help shall be highly appreciated.










    share|cite|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      I am working with the Hermite functions $h_n(x)$ such that $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}.$ So, if $mneq n$, we know that the integral $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}=0$, but I am interested in understanding the behavior of this integral over a finite interval. More precisely if I fix $[-a,a]subset mathbb{R}$, and look at the integral $$I_n:=int_{-sqrt{n}a}^{sqrt{n}b}h_n(x)h_{n+1}(x)e^{-x^2/2}dx,$$
      It's clear that $I_nto 0$, but can we say something about the rate at which it goes to 0? I guess that $I_n=O(n^{-2}),$ but I could not find any result in this direction.
      One can of course ask for many more generalizations but this is something which I need to use in an estimate I am trying to prove.
      Any help shall be highly appreciated.










      share|cite|improve this question













      I am working with the Hermite functions $h_n(x)$ such that $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}.$ So, if $mneq n$, we know that the integral $int_{mathbb{R}}h_n(x)h_m(x)e^{-x^2/2}dx=delta_{n,m}=0$, but I am interested in understanding the behavior of this integral over a finite interval. More precisely if I fix $[-a,a]subset mathbb{R}$, and look at the integral $$I_n:=int_{-sqrt{n}a}^{sqrt{n}b}h_n(x)h_{n+1}(x)e^{-x^2/2}dx,$$
      It's clear that $I_nto 0$, but can we say something about the rate at which it goes to 0? I guess that $I_n=O(n^{-2}),$ but I could not find any result in this direction.
      One can of course ask for many more generalizations but this is something which I need to use in an estimate I am trying to prove.
      Any help shall be highly appreciated.







      asymptotics hermite-polynomials






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 17 at 20:08









      WhoKnowsWho

      717




      717



























          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',
          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%2f3002753%2fintegral-of-product-of-hermite-functions-over-finite-interval%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown






























          active

          oldest

          votes













          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%2f3002753%2fintegral-of-product-of-hermite-functions-over-finite-interval%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

          AnyDesk - Fatal Program Failure

          How to calibrate 16:9 built-in touch-screen to a 4:3 resolution?

          QoS: MAC-Priority for clients behind a repeater