Orthogonal complement of $H_a =left{g in V: gleft(t+frac{1}{2}right)=g(t) right}$











up vote
1
down vote

favorite












If $;;V={ f:mathbb{R}rightarrow mathbb{C} |; f text{ is continuous and has period }1}$, $;; langle f | g rangle$ is defined as $ langle f | g rangle = int_0^1 overline{f(t)}g(t)dt$, $forall f,g in V;;$ and $;;H_a =left{gin V: gleft(t+frac{1}{2}right)=g(t) right};;;$ (period $frac{1}{2}$).



What can be said about $H_a^perp$?



$H_a^perp = {fin V: langle f | g rangle=0, forall gin H_a }
= left{fin V: langle f | g rangle=0, forall g: gleft(t+frac{1}{2}right)=g(t) right}
$










share|cite|improve this question
























  • You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
    – астон вілла олоф мэллбэрг
    Nov 20 at 11:37















up vote
1
down vote

favorite












If $;;V={ f:mathbb{R}rightarrow mathbb{C} |; f text{ is continuous and has period }1}$, $;; langle f | g rangle$ is defined as $ langle f | g rangle = int_0^1 overline{f(t)}g(t)dt$, $forall f,g in V;;$ and $;;H_a =left{gin V: gleft(t+frac{1}{2}right)=g(t) right};;;$ (period $frac{1}{2}$).



What can be said about $H_a^perp$?



$H_a^perp = {fin V: langle f | g rangle=0, forall gin H_a }
= left{fin V: langle f | g rangle=0, forall g: gleft(t+frac{1}{2}right)=g(t) right}
$










share|cite|improve this question
























  • You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
    – астон вілла олоф мэллбэрг
    Nov 20 at 11:37













up vote
1
down vote

favorite









up vote
1
down vote

favorite











If $;;V={ f:mathbb{R}rightarrow mathbb{C} |; f text{ is continuous and has period }1}$, $;; langle f | g rangle$ is defined as $ langle f | g rangle = int_0^1 overline{f(t)}g(t)dt$, $forall f,g in V;;$ and $;;H_a =left{gin V: gleft(t+frac{1}{2}right)=g(t) right};;;$ (period $frac{1}{2}$).



What can be said about $H_a^perp$?



$H_a^perp = {fin V: langle f | g rangle=0, forall gin H_a }
= left{fin V: langle f | g rangle=0, forall g: gleft(t+frac{1}{2}right)=g(t) right}
$










share|cite|improve this question















If $;;V={ f:mathbb{R}rightarrow mathbb{C} |; f text{ is continuous and has period }1}$, $;; langle f | g rangle$ is defined as $ langle f | g rangle = int_0^1 overline{f(t)}g(t)dt$, $forall f,g in V;;$ and $;;H_a =left{gin V: gleft(t+frac{1}{2}right)=g(t) right};;;$ (period $frac{1}{2}$).



What can be said about $H_a^perp$?



$H_a^perp = {fin V: langle f | g rangle=0, forall gin H_a }
= left{fin V: langle f | g rangle=0, forall g: gleft(t+frac{1}{2}right)=g(t) right}
$







inner-product-space orthogonality






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 20 at 11:14









rtybase

10.2k21433




10.2k21433










asked Nov 20 at 11:05









Filip

427




427












  • You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
    – астон вілла олоф мэллбэрг
    Nov 20 at 11:37


















  • You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
    – астон вілла олоф мэллбэрг
    Nov 20 at 11:37
















You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
– астон вілла олоф мэллбэрг
Nov 20 at 11:37




You can proceed further than just the definition. Try to find some elements of $H_a^perp$.
– астон вілла олоф мэллбэрг
Nov 20 at 11:37










1 Answer
1






active

oldest

votes

















up vote
3
down vote



accepted










Hints: $$0=int_0^{1/2} f(x)g(x) , dx+int_{1/2}^{1} f(x)g(x) , dx=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y-frac 1 2) , dy$$ $$=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y) , dy$$ for all continuous functions $g$ on $[0,frac 1 2]$ with $g(0)=g(frac 1 2)$ iff $f(y-frac 1 2)=-f(y)$. Thus the orthogonal complement consists of all continuous functions $f$ with period $1$ satisfying $f(x-frac 1 2)=-f(x)$ for all $x$. Some details are missing but I think you can fill in the details.






share|cite|improve this answer





















    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%2f3006189%2forthogonal-complement-of-h-a-left-g-in-v-g-leftt-frac12-right-gt%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








    up vote
    3
    down vote



    accepted










    Hints: $$0=int_0^{1/2} f(x)g(x) , dx+int_{1/2}^{1} f(x)g(x) , dx=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y-frac 1 2) , dy$$ $$=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y) , dy$$ for all continuous functions $g$ on $[0,frac 1 2]$ with $g(0)=g(frac 1 2)$ iff $f(y-frac 1 2)=-f(y)$. Thus the orthogonal complement consists of all continuous functions $f$ with period $1$ satisfying $f(x-frac 1 2)=-f(x)$ for all $x$. Some details are missing but I think you can fill in the details.






    share|cite|improve this answer

























      up vote
      3
      down vote



      accepted










      Hints: $$0=int_0^{1/2} f(x)g(x) , dx+int_{1/2}^{1} f(x)g(x) , dx=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y-frac 1 2) , dy$$ $$=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y) , dy$$ for all continuous functions $g$ on $[0,frac 1 2]$ with $g(0)=g(frac 1 2)$ iff $f(y-frac 1 2)=-f(y)$. Thus the orthogonal complement consists of all continuous functions $f$ with period $1$ satisfying $f(x-frac 1 2)=-f(x)$ for all $x$. Some details are missing but I think you can fill in the details.






      share|cite|improve this answer























        up vote
        3
        down vote



        accepted







        up vote
        3
        down vote



        accepted






        Hints: $$0=int_0^{1/2} f(x)g(x) , dx+int_{1/2}^{1} f(x)g(x) , dx=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y-frac 1 2) , dy$$ $$=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y) , dy$$ for all continuous functions $g$ on $[0,frac 1 2]$ with $g(0)=g(frac 1 2)$ iff $f(y-frac 1 2)=-f(y)$. Thus the orthogonal complement consists of all continuous functions $f$ with period $1$ satisfying $f(x-frac 1 2)=-f(x)$ for all $x$. Some details are missing but I think you can fill in the details.






        share|cite|improve this answer












        Hints: $$0=int_0^{1/2} f(x)g(x) , dx+int_{1/2}^{1} f(x)g(x) , dx=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y-frac 1 2) , dy$$ $$=int_0^{1/2} f(x)g(x) , dx+int_{0}^{1/2} f(y-frac 1 2)g(y) , dy$$ for all continuous functions $g$ on $[0,frac 1 2]$ with $g(0)=g(frac 1 2)$ iff $f(y-frac 1 2)=-f(y)$. Thus the orthogonal complement consists of all continuous functions $f$ with period $1$ satisfying $f(x-frac 1 2)=-f(x)$ for all $x$. Some details are missing but I think you can fill in the details.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Nov 20 at 11:54









        Kavi Rama Murthy

        44.8k31852




        44.8k31852






























            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%2f3006189%2forthogonal-complement-of-h-a-left-g-in-v-g-leftt-frac12-right-gt%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

            Ellipse (mathématiques)

            Quarter-circle Tiles

            Mont Emei