Continuous bijections and their inverses












1












$begingroup$


Are there any theorems characterizing the continuity of the inverses of bijections between certain classes of particular spaces. E.g. it seems to me the inverse of any continuous bijection between connected subsets of $mathbb{R}$ is continouos. It seems that most counterexamples require highly specific spaces. I'm thinking there might be something along the lines of any continuous bijection between homeomorphic spaces has a continuous inverse. Any of this make sense?










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
    $endgroup$
    – freakish
    Dec 27 '18 at 18:28












  • $begingroup$
    I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
    $endgroup$
    – DanielWainfleet
    Jan 3 at 10:26


















1












$begingroup$


Are there any theorems characterizing the continuity of the inverses of bijections between certain classes of particular spaces. E.g. it seems to me the inverse of any continuous bijection between connected subsets of $mathbb{R}$ is continouos. It seems that most counterexamples require highly specific spaces. I'm thinking there might be something along the lines of any continuous bijection between homeomorphic spaces has a continuous inverse. Any of this make sense?










share|cite|improve this question









$endgroup$








  • 1




    $begingroup$
    Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
    $endgroup$
    – freakish
    Dec 27 '18 at 18:28












  • $begingroup$
    I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
    $endgroup$
    – DanielWainfleet
    Jan 3 at 10:26
















1












1








1





$begingroup$


Are there any theorems characterizing the continuity of the inverses of bijections between certain classes of particular spaces. E.g. it seems to me the inverse of any continuous bijection between connected subsets of $mathbb{R}$ is continouos. It seems that most counterexamples require highly specific spaces. I'm thinking there might be something along the lines of any continuous bijection between homeomorphic spaces has a continuous inverse. Any of this make sense?










share|cite|improve this question









$endgroup$




Are there any theorems characterizing the continuity of the inverses of bijections between certain classes of particular spaces. E.g. it seems to me the inverse of any continuous bijection between connected subsets of $mathbb{R}$ is continouos. It seems that most counterexamples require highly specific spaces. I'm thinking there might be something along the lines of any continuous bijection between homeomorphic spaces has a continuous inverse. Any of this make sense?







general-topology






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 27 '18 at 16:36









Keefer RowanKeefer Rowan

21010




21010








  • 1




    $begingroup$
    Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
    $endgroup$
    – freakish
    Dec 27 '18 at 18:28












  • $begingroup$
    I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
    $endgroup$
    – DanielWainfleet
    Jan 3 at 10:26
















  • 1




    $begingroup$
    Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
    $endgroup$
    – freakish
    Dec 27 '18 at 18:28












  • $begingroup$
    I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
    $endgroup$
    – DanielWainfleet
    Jan 3 at 10:26










1




1




$begingroup$
Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
$endgroup$
– freakish
Dec 27 '18 at 18:28






$begingroup$
Yes, the question makes sense. The answer to it is "no". See this: math.stackexchange.com/questions/20913/…
$endgroup$
– freakish
Dec 27 '18 at 18:28














$begingroup$
I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
$endgroup$
– DanielWainfleet
Jan 3 at 10:26






$begingroup$
I can give you an example of a complex normed linear space $X$ and a continuous linear bijection $f:Xto X$ whose inverse is not continuous.
$endgroup$
– DanielWainfleet
Jan 3 at 10:26












1 Answer
1






active

oldest

votes


















1












$begingroup$

Indeed, in particular cases the inverse of a continuous bijection $f:Xto Y$ is continuous. Namely, when $X$ is a compact, $Y$ is Hausdorff (well-known and very easy to prove) or when $X$ is an open subset of $Bbb R^n$ and $YsubsetBbb R^n$, by invariance of domain.






share|cite|improve this answer









$endgroup$














    Your Answer








    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%2f3054131%2fcontinuous-bijections-and-their-inverses%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












    $begingroup$

    Indeed, in particular cases the inverse of a continuous bijection $f:Xto Y$ is continuous. Namely, when $X$ is a compact, $Y$ is Hausdorff (well-known and very easy to prove) or when $X$ is an open subset of $Bbb R^n$ and $YsubsetBbb R^n$, by invariance of domain.






    share|cite|improve this answer









    $endgroup$


















      1












      $begingroup$

      Indeed, in particular cases the inverse of a continuous bijection $f:Xto Y$ is continuous. Namely, when $X$ is a compact, $Y$ is Hausdorff (well-known and very easy to prove) or when $X$ is an open subset of $Bbb R^n$ and $YsubsetBbb R^n$, by invariance of domain.






      share|cite|improve this answer









      $endgroup$
















        1












        1








        1





        $begingroup$

        Indeed, in particular cases the inverse of a continuous bijection $f:Xto Y$ is continuous. Namely, when $X$ is a compact, $Y$ is Hausdorff (well-known and very easy to prove) or when $X$ is an open subset of $Bbb R^n$ and $YsubsetBbb R^n$, by invariance of domain.






        share|cite|improve this answer









        $endgroup$



        Indeed, in particular cases the inverse of a continuous bijection $f:Xto Y$ is continuous. Namely, when $X$ is a compact, $Y$ is Hausdorff (well-known and very easy to prove) or when $X$ is an open subset of $Bbb R^n$ and $YsubsetBbb R^n$, by invariance of domain.







        share|cite|improve this answer












        share|cite|improve this answer



        share|cite|improve this answer










        answered Jan 3 at 4:34









        Alex RavskyAlex Ravsky

        43.3k32583




        43.3k32583






























            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%2f3054131%2fcontinuous-bijections-and-their-inverses%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

            Le Mesnil-Réaume

            Ida-Boy-Ed-Garten

            web3.py web3.isConnected() returns false always