Bogachev change of variables theorem.












2














I am reading the Bogachev's change of variable theorem proof. And I am stuck in an argument contained in it:



Let $F:Usubset mathbb{R}^nto mathbb{R}^n$ an injective $C¹$ map. Given $epsilon>$ there exist $delta>0$ s.t $forall x,y in U,~|x-y|<delta$ implies
$$
F(x)-F(y)=F^{'}(x)(y-x)+r(x,y)
$$

where $|r(x,y)|leq epsilon |x-y|$.



Here is where I am stucked:



Claim: Let $Q$ be a cube with center $x_0$ and diameter less than $delta.$ If $|det F'(x_0)|leq sqrt{epsilon}$ then we have that
$$
lambda (L(Q))-lambda(F(Q))leq sqrt{epsilon}lambda (Q)
$$

where $L(x)=F^{'}(x_0)(x-x_0)+F(x_0)$ and $lambda$ is the $n$-dimensional lebesgue measure.



Can someone give me some help?



Comment: I think the argument pass over to give some inferior bound for
$text{diam}( F(U))$ by using in some way the inequality
$|F(x)-F(y)|geq |F^{'}(x_0)(x-y)|-|r(x,y|$.










share|cite|improve this question





























    2














    I am reading the Bogachev's change of variable theorem proof. And I am stuck in an argument contained in it:



    Let $F:Usubset mathbb{R}^nto mathbb{R}^n$ an injective $C¹$ map. Given $epsilon>$ there exist $delta>0$ s.t $forall x,y in U,~|x-y|<delta$ implies
    $$
    F(x)-F(y)=F^{'}(x)(y-x)+r(x,y)
    $$

    where $|r(x,y)|leq epsilon |x-y|$.



    Here is where I am stucked:



    Claim: Let $Q$ be a cube with center $x_0$ and diameter less than $delta.$ If $|det F'(x_0)|leq sqrt{epsilon}$ then we have that
    $$
    lambda (L(Q))-lambda(F(Q))leq sqrt{epsilon}lambda (Q)
    $$

    where $L(x)=F^{'}(x_0)(x-x_0)+F(x_0)$ and $lambda$ is the $n$-dimensional lebesgue measure.



    Can someone give me some help?



    Comment: I think the argument pass over to give some inferior bound for
    $text{diam}( F(U))$ by using in some way the inequality
    $|F(x)-F(y)|geq |F^{'}(x_0)(x-y)|-|r(x,y|$.










    share|cite|improve this question



























      2












      2








      2







      I am reading the Bogachev's change of variable theorem proof. And I am stuck in an argument contained in it:



      Let $F:Usubset mathbb{R}^nto mathbb{R}^n$ an injective $C¹$ map. Given $epsilon>$ there exist $delta>0$ s.t $forall x,y in U,~|x-y|<delta$ implies
      $$
      F(x)-F(y)=F^{'}(x)(y-x)+r(x,y)
      $$

      where $|r(x,y)|leq epsilon |x-y|$.



      Here is where I am stucked:



      Claim: Let $Q$ be a cube with center $x_0$ and diameter less than $delta.$ If $|det F'(x_0)|leq sqrt{epsilon}$ then we have that
      $$
      lambda (L(Q))-lambda(F(Q))leq sqrt{epsilon}lambda (Q)
      $$

      where $L(x)=F^{'}(x_0)(x-x_0)+F(x_0)$ and $lambda$ is the $n$-dimensional lebesgue measure.



      Can someone give me some help?



      Comment: I think the argument pass over to give some inferior bound for
      $text{diam}( F(U))$ by using in some way the inequality
      $|F(x)-F(y)|geq |F^{'}(x_0)(x-y)|-|r(x,y|$.










      share|cite|improve this question















      I am reading the Bogachev's change of variable theorem proof. And I am stuck in an argument contained in it:



      Let $F:Usubset mathbb{R}^nto mathbb{R}^n$ an injective $C¹$ map. Given $epsilon>$ there exist $delta>0$ s.t $forall x,y in U,~|x-y|<delta$ implies
      $$
      F(x)-F(y)=F^{'}(x)(y-x)+r(x,y)
      $$

      where $|r(x,y)|leq epsilon |x-y|$.



      Here is where I am stucked:



      Claim: Let $Q$ be a cube with center $x_0$ and diameter less than $delta.$ If $|det F'(x_0)|leq sqrt{epsilon}$ then we have that
      $$
      lambda (L(Q))-lambda(F(Q))leq sqrt{epsilon}lambda (Q)
      $$

      where $L(x)=F^{'}(x_0)(x-x_0)+F(x_0)$ and $lambda$ is the $n$-dimensional lebesgue measure.



      Can someone give me some help?



      Comment: I think the argument pass over to give some inferior bound for
      $text{diam}( F(U))$ by using in some way the inequality
      $|F(x)-F(y)|geq |F^{'}(x_0)(x-y)|-|r(x,y|$.







      measure-theory lebesgue-integral lebesgue-measure






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Nov 18 at 16:22

























      asked Nov 18 at 15:35









      Eduardo

      551112




      551112






















          1 Answer
          1






          active

          oldest

          votes


















          1














          I don't know enough measure theory but since $lambda(L(Q))=det L cdot lambda(Q)$, you could try to prove that $det L le frac{lambda(F(Q))}{lambda(Q)} + |det F'(x_0)|$.






          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',
            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%2f3003685%2fbogachev-change-of-variables-theorem%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














            I don't know enough measure theory but since $lambda(L(Q))=det L cdot lambda(Q)$, you could try to prove that $det L le frac{lambda(F(Q))}{lambda(Q)} + |det F'(x_0)|$.






            share|cite|improve this answer


























              1














              I don't know enough measure theory but since $lambda(L(Q))=det L cdot lambda(Q)$, you could try to prove that $det L le frac{lambda(F(Q))}{lambda(Q)} + |det F'(x_0)|$.






              share|cite|improve this answer
























                1












                1








                1






                I don't know enough measure theory but since $lambda(L(Q))=det L cdot lambda(Q)$, you could try to prove that $det L le frac{lambda(F(Q))}{lambda(Q)} + |det F'(x_0)|$.






                share|cite|improve this answer












                I don't know enough measure theory but since $lambda(L(Q))=det L cdot lambda(Q)$, you could try to prove that $det L le frac{lambda(F(Q))}{lambda(Q)} + |det F'(x_0)|$.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Nov 18 at 17:06









                lzralbu

                560412




                560412






























                    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%2f3003685%2fbogachev-change-of-variables-theorem%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