simultanious convergence of integral norms












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Suppose I have a sequence of measurable functions $f_jin L^pcap L^q$. I am wondering what can I deduce about the behavior of the sequence in one space based on its behavior in the other.



Specifically, I am interested in the following two questions:




  1. If $f_j$ is cauchy with respect to the norm on $L^p$ is it cauchy with respect to the $L^q$ norm as well?

  2. If $f_j$ converges in $L^p$ to $g$ and in $L^q$ to $h$, is it true that $g=h$ almost everywhere?


Similar to this question but I am not necessarily interested in the case of $mu(X)<infty$










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    1












    $begingroup$


    Suppose I have a sequence of measurable functions $f_jin L^pcap L^q$. I am wondering what can I deduce about the behavior of the sequence in one space based on its behavior in the other.



    Specifically, I am interested in the following two questions:




    1. If $f_j$ is cauchy with respect to the norm on $L^p$ is it cauchy with respect to the $L^q$ norm as well?

    2. If $f_j$ converges in $L^p$ to $g$ and in $L^q$ to $h$, is it true that $g=h$ almost everywhere?


    Similar to this question but I am not necessarily interested in the case of $mu(X)<infty$










    share|cite|improve this question









    $endgroup$















      1












      1








      1





      $begingroup$


      Suppose I have a sequence of measurable functions $f_jin L^pcap L^q$. I am wondering what can I deduce about the behavior of the sequence in one space based on its behavior in the other.



      Specifically, I am interested in the following two questions:




      1. If $f_j$ is cauchy with respect to the norm on $L^p$ is it cauchy with respect to the $L^q$ norm as well?

      2. If $f_j$ converges in $L^p$ to $g$ and in $L^q$ to $h$, is it true that $g=h$ almost everywhere?


      Similar to this question but I am not necessarily interested in the case of $mu(X)<infty$










      share|cite|improve this question









      $endgroup$




      Suppose I have a sequence of measurable functions $f_jin L^pcap L^q$. I am wondering what can I deduce about the behavior of the sequence in one space based on its behavior in the other.



      Specifically, I am interested in the following two questions:




      1. If $f_j$ is cauchy with respect to the norm on $L^p$ is it cauchy with respect to the $L^q$ norm as well?

      2. If $f_j$ converges in $L^p$ to $g$ and in $L^q$ to $h$, is it true that $g=h$ almost everywhere?


      Similar to this question but I am not necessarily interested in the case of $mu(X)<infty$







      convergence metric-spaces lebesgue-integral lp-spaces






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      asked Dec 23 '18 at 21:40









      Bar AlonBar Alon

      504115




      504115






















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          $begingroup$

          Whether convergence in one $L^p$ implies convergence in another one depends on the ground space on which the functions are defined. The case of finite measure is explained by Hölder's inequality and the case of a purely atomic space is the other way round.



          For the other question: convergence in any $L^p$ implies convergence in measure which implies that the limits have to be the same.






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            1 Answer
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            1 Answer
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            active

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            active

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            $begingroup$

            Whether convergence in one $L^p$ implies convergence in another one depends on the ground space on which the functions are defined. The case of finite measure is explained by Hölder's inequality and the case of a purely atomic space is the other way round.



            For the other question: convergence in any $L^p$ implies convergence in measure which implies that the limits have to be the same.






            share|cite|improve this answer









            $endgroup$


















              2












              $begingroup$

              Whether convergence in one $L^p$ implies convergence in another one depends on the ground space on which the functions are defined. The case of finite measure is explained by Hölder's inequality and the case of a purely atomic space is the other way round.



              For the other question: convergence in any $L^p$ implies convergence in measure which implies that the limits have to be the same.






              share|cite|improve this answer









              $endgroup$
















                2












                2








                2





                $begingroup$

                Whether convergence in one $L^p$ implies convergence in another one depends on the ground space on which the functions are defined. The case of finite measure is explained by Hölder's inequality and the case of a purely atomic space is the other way round.



                For the other question: convergence in any $L^p$ implies convergence in measure which implies that the limits have to be the same.






                share|cite|improve this answer









                $endgroup$



                Whether convergence in one $L^p$ implies convergence in another one depends on the ground space on which the functions are defined. The case of finite measure is explained by Hölder's inequality and the case of a purely atomic space is the other way round.



                For the other question: convergence in any $L^p$ implies convergence in measure which implies that the limits have to be the same.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 23 '18 at 22:31









                DirkDirk

                8,8102447




                8,8102447






























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