How to define norm on semi vector spaces?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
0
down vote

favorite












And and can we give proofs different from vector space norm proofs with its restriction?Can we give standard proofs with the lack of additive identity and additive inverse property?







share|cite|improve this question























    up vote
    0
    down vote

    favorite












    And and can we give proofs different from vector space norm proofs with its restriction?Can we give standard proofs with the lack of additive identity and additive inverse property?







    share|cite|improve this question





















      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      And and can we give proofs different from vector space norm proofs with its restriction?Can we give standard proofs with the lack of additive identity and additive inverse property?







      share|cite|improve this question











      And and can we give proofs different from vector space norm proofs with its restriction?Can we give standard proofs with the lack of additive identity and additive inverse property?









      share|cite|improve this question










      share|cite|improve this question




      share|cite|improve this question









      asked Jul 28 at 15:31









      Sherlin

      13




      13




















          1 Answer
          1






          active

          oldest

          votes

















          up vote
          0
          down vote













          No in general. For instance, the gliding hump proof of the uniform boundedness principle fails horribly. Also, the Hahn-Banach theorem can't be proven in the usual way because we can't pass to zero or to a subspace.



          The strategy to obtain results would be to embed the semi vector space into some vector space. This works e.g. when the semi vector space has some sort of "basis".






          share|cite|improve this answer





















          • Thnx can u give me some more properties..
            – Sherlin
            Jul 28 at 15:40










          • It would help greatly if you had a particular semi vector space in mind...
            – AlgebraicsAnonymous
            Jul 28 at 15:41










          • If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
            – AlgebraicsAnonymous
            Jul 28 at 15:43










          • Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
            – Sherlin
            Jul 28 at 15:50










          • Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
            – AlgebraicsAnonymous
            Jul 28 at 15:52










          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',
          convertImagesToLinks: true,
          noModals: false,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: 10,
          bindNavPrevention: true,
          postfix: "",
          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%2f2865338%2fhow-to-define-norm-on-semi-vector-spaces%23new-answer', 'question_page');

          );

          Post as a guest






























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes








          up vote
          0
          down vote













          No in general. For instance, the gliding hump proof of the uniform boundedness principle fails horribly. Also, the Hahn-Banach theorem can't be proven in the usual way because we can't pass to zero or to a subspace.



          The strategy to obtain results would be to embed the semi vector space into some vector space. This works e.g. when the semi vector space has some sort of "basis".






          share|cite|improve this answer





















          • Thnx can u give me some more properties..
            – Sherlin
            Jul 28 at 15:40










          • It would help greatly if you had a particular semi vector space in mind...
            – AlgebraicsAnonymous
            Jul 28 at 15:41










          • If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
            – AlgebraicsAnonymous
            Jul 28 at 15:43










          • Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
            – Sherlin
            Jul 28 at 15:50










          • Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
            – AlgebraicsAnonymous
            Jul 28 at 15:52














          up vote
          0
          down vote













          No in general. For instance, the gliding hump proof of the uniform boundedness principle fails horribly. Also, the Hahn-Banach theorem can't be proven in the usual way because we can't pass to zero or to a subspace.



          The strategy to obtain results would be to embed the semi vector space into some vector space. This works e.g. when the semi vector space has some sort of "basis".






          share|cite|improve this answer





















          • Thnx can u give me some more properties..
            – Sherlin
            Jul 28 at 15:40










          • It would help greatly if you had a particular semi vector space in mind...
            – AlgebraicsAnonymous
            Jul 28 at 15:41










          • If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
            – AlgebraicsAnonymous
            Jul 28 at 15:43










          • Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
            – Sherlin
            Jul 28 at 15:50










          • Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
            – AlgebraicsAnonymous
            Jul 28 at 15:52












          up vote
          0
          down vote










          up vote
          0
          down vote









          No in general. For instance, the gliding hump proof of the uniform boundedness principle fails horribly. Also, the Hahn-Banach theorem can't be proven in the usual way because we can't pass to zero or to a subspace.



          The strategy to obtain results would be to embed the semi vector space into some vector space. This works e.g. when the semi vector space has some sort of "basis".






          share|cite|improve this answer













          No in general. For instance, the gliding hump proof of the uniform boundedness principle fails horribly. Also, the Hahn-Banach theorem can't be proven in the usual way because we can't pass to zero or to a subspace.



          The strategy to obtain results would be to embed the semi vector space into some vector space. This works e.g. when the semi vector space has some sort of "basis".







          share|cite|improve this answer













          share|cite|improve this answer



          share|cite|improve this answer











          answered Jul 28 at 15:36









          AlgebraicsAnonymous

          66611




          66611











          • Thnx can u give me some more properties..
            – Sherlin
            Jul 28 at 15:40










          • It would help greatly if you had a particular semi vector space in mind...
            – AlgebraicsAnonymous
            Jul 28 at 15:41










          • If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
            – AlgebraicsAnonymous
            Jul 28 at 15:43










          • Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
            – Sherlin
            Jul 28 at 15:50










          • Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
            – AlgebraicsAnonymous
            Jul 28 at 15:52
















          • Thnx can u give me some more properties..
            – Sherlin
            Jul 28 at 15:40










          • It would help greatly if you had a particular semi vector space in mind...
            – AlgebraicsAnonymous
            Jul 28 at 15:41










          • If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
            – AlgebraicsAnonymous
            Jul 28 at 15:43










          • Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
            – Sherlin
            Jul 28 at 15:50










          • Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
            – AlgebraicsAnonymous
            Jul 28 at 15:52















          Thnx can u give me some more properties..
          – Sherlin
          Jul 28 at 15:40




          Thnx can u give me some more properties..
          – Sherlin
          Jul 28 at 15:40












          It would help greatly if you had a particular semi vector space in mind...
          – AlgebraicsAnonymous
          Jul 28 at 15:41




          It would help greatly if you had a particular semi vector space in mind...
          – AlgebraicsAnonymous
          Jul 28 at 15:41












          If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
          – AlgebraicsAnonymous
          Jul 28 at 15:43




          If you, for instance, were to talk about a convex cone in a Hilbert space, then things would work fine...
          – AlgebraicsAnonymous
          Jul 28 at 15:43












          Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
          – Sherlin
          Jul 28 at 15:50




          Can it work with 0 included and defining inner product on it and can we get different proofs ..i am specific abt the semi field of positive real numbers can u give me some simple semi vector spaces so that i can try to bring its norm properties
          – Sherlin
          Jul 28 at 15:50












          Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
          – AlgebraicsAnonymous
          Jul 28 at 15:52




          Possibly one could formally define the extension to the real numbers as a positive and negative part, just like the Grothendieck group construction. In this case, one would have an embedding and could get the results one wants from that.
          – AlgebraicsAnonymous
          Jul 28 at 15:52












           

          draft saved


          draft discarded


























           


          draft saved


          draft discarded














          StackExchange.ready(
          function ()
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2865338%2fhow-to-define-norm-on-semi-vector-spaces%23new-answer', 'question_page');

          );

          Post as a guest













































































          Comments

          Popular posts from this blog

          Color the edges and diagonals of a regular polygon

          Relationship between determinant of matrix and determinant of adjoint?

          What is the equation of a 3D cone with generalised tilt?