Class field axiom III-1 in Serre's “Local Fields”












1












$begingroup$


Let $F/E$ be a finite extension of local fields, and $N = N_{F/E} : F^* to E^*$ be the norm map (it is continuos).
And consider an axiom:




$N$ has closed image and compact kernel.




In the book, the author says that this condition is equivalent to that $N$ is proper.
But I can't show it.
Please help.



P.S. This condition holds in this case.
I use the word "axiom" because I use the explicit terminology for simplification (the author uses class field formation).
So please show the equivalence using only locally compactness, countability at infinity of $E, F$ and continuity of $N$.










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$endgroup$

















    1












    $begingroup$


    Let $F/E$ be a finite extension of local fields, and $N = N_{F/E} : F^* to E^*$ be the norm map (it is continuos).
    And consider an axiom:




    $N$ has closed image and compact kernel.




    In the book, the author says that this condition is equivalent to that $N$ is proper.
    But I can't show it.
    Please help.



    P.S. This condition holds in this case.
    I use the word "axiom" because I use the explicit terminology for simplification (the author uses class field formation).
    So please show the equivalence using only locally compactness, countability at infinity of $E, F$ and continuity of $N$.










    share|cite|improve this question











    $endgroup$















      1












      1








      1


      1



      $begingroup$


      Let $F/E$ be a finite extension of local fields, and $N = N_{F/E} : F^* to E^*$ be the norm map (it is continuos).
      And consider an axiom:




      $N$ has closed image and compact kernel.




      In the book, the author says that this condition is equivalent to that $N$ is proper.
      But I can't show it.
      Please help.



      P.S. This condition holds in this case.
      I use the word "axiom" because I use the explicit terminology for simplification (the author uses class field formation).
      So please show the equivalence using only locally compactness, countability at infinity of $E, F$ and continuity of $N$.










      share|cite|improve this question











      $endgroup$




      Let $F/E$ be a finite extension of local fields, and $N = N_{F/E} : F^* to E^*$ be the norm map (it is continuos).
      And consider an axiom:




      $N$ has closed image and compact kernel.




      In the book, the author says that this condition is equivalent to that $N$ is proper.
      But I can't show it.
      Please help.



      P.S. This condition holds in this case.
      I use the word "axiom" because I use the explicit terminology for simplification (the author uses class field formation).
      So please show the equivalence using only locally compactness, countability at infinity of $E, F$ and continuity of $N$.







      algebraic-number-theory class-field-theory






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




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      edited Feb 22 at 0:22









      user38077

      31




      31










      asked Jan 30 at 8:53









      agababibuagababibu

      413110




      413110






















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