What is the compactness uniqueness argument












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I have come across the term "compactness uniqueness argument" in many inverse problems papers and books but the proof are usually omitted. Could anyone give such an example and relevant references?










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  • 1




    $begingroup$
    What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
    $endgroup$
    – Mindlack
    Jan 9 at 21:59






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    I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
    $endgroup$
    – DanielWainfleet
    Jan 10 at 0:54












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    Could you give an example of a reference to where the argument is used?
    $endgroup$
    – Tommi Brander
    Jan 10 at 10:47
















0












$begingroup$


I have come across the term "compactness uniqueness argument" in many inverse problems papers and books but the proof are usually omitted. Could anyone give such an example and relevant references?










share|cite|improve this question











$endgroup$








  • 1




    $begingroup$
    What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
    $endgroup$
    – Mindlack
    Jan 9 at 21:59






  • 1




    $begingroup$
    I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
    $endgroup$
    – DanielWainfleet
    Jan 10 at 0:54












  • $begingroup$
    Could you give an example of a reference to where the argument is used?
    $endgroup$
    – Tommi Brander
    Jan 10 at 10:47














0












0








0





$begingroup$


I have come across the term "compactness uniqueness argument" in many inverse problems papers and books but the proof are usually omitted. Could anyone give such an example and relevant references?










share|cite|improve this question











$endgroup$




I have come across the term "compactness uniqueness argument" in many inverse problems papers and books but the proof are usually omitted. Could anyone give such an example and relevant references?







compactness inverse-problems






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 9 at 21:46









David G. Stork

10.9k31432




10.9k31432










asked Jan 9 at 21:43









KKKKKK

1658




1658








  • 1




    $begingroup$
    What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
    $endgroup$
    – Mindlack
    Jan 9 at 21:59






  • 1




    $begingroup$
    I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
    $endgroup$
    – DanielWainfleet
    Jan 10 at 0:54












  • $begingroup$
    Could you give an example of a reference to where the argument is used?
    $endgroup$
    – Tommi Brander
    Jan 10 at 10:47














  • 1




    $begingroup$
    What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
    $endgroup$
    – Mindlack
    Jan 9 at 21:59






  • 1




    $begingroup$
    I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
    $endgroup$
    – DanielWainfleet
    Jan 10 at 0:54












  • $begingroup$
    Could you give an example of a reference to where the argument is used?
    $endgroup$
    – Tommi Brander
    Jan 10 at 10:47








1




1




$begingroup$
What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
$endgroup$
– Mindlack
Jan 9 at 21:59




$begingroup$
What kind of statement (what kind of uniqueness?) is this sort of argument supposed to prove?
$endgroup$
– Mindlack
Jan 9 at 21:59




1




1




$begingroup$
I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
$endgroup$
– DanielWainfleet
Jan 10 at 0:54






$begingroup$
I don't think this can be answered unless you show or link or cite at least one (complete) example. The only things that come to my mind are (1). If $X, Y$ are compact Hausdorff spaces and $f:Xto Y$ is a continuous bijection then $f$ is a homeomorphism... (2). If $T,U$ are compact Hausdorff topologies on $X$ and $Usubset T$ , then $U=T$. Because $id_X$ is a continuous bijection from $(X, T)$ to $(X,U)$ so by (1), $ id_X $ is a homeomorphism from $(X,T)$ to $ (X,U)$.
$endgroup$
– DanielWainfleet
Jan 10 at 0:54














$begingroup$
Could you give an example of a reference to where the argument is used?
$endgroup$
– Tommi Brander
Jan 10 at 10:47




$begingroup$
Could you give an example of a reference to where the argument is used?
$endgroup$
– Tommi Brander
Jan 10 at 10:47










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