$(V, geq)$ Banach lattice, $(W, geq)$ Riesz space, then $mathcal{L}(V, W)^+ = mathcal{B}(V, W)^+$












0














Let $(V, geq)$ be a Banach lattice and $(W, geq)$ be Riesz space whose whose positive cone is generated by some positive element of the space. Then $mathcal{L}(V, W)^+ = mathcal{B}(V, W)^+$, where $mathcal{L}(V, W)^+$, $mathcal{B}(V, W)^+$ are the sets of positive elements of $mathcal{L}(V, W)$ and $mathcal{B}(V, W)$, respectevely.



Trivially, $mathcal{B}(V, W)^+ subset mathcal{L}(V, W)^+$. So it remains to show that $mathcal{L}(V, W)^+ subset mathcal{B}(V, W)^+$, which means that every positive linear functional between $V$ and $W$ is bounded.



Let $fcolon V rightarrow W in mathcal{L}(V, W)^+$.Thus, by definition, $f(v) geq 0$ if $v geq 0$.



So, for $v geq 0$, we have that $f(v) in W^+$, which is generated by some positive element of $W$. Formally, there is $w_0$ such that $W^+ = cup_{alpha in mathbb{R}^+_0} [0, alpha w_0]$.



Then, there is $beta in mathbb{R}^+_0$ such that $f(v) = beta w_0$ (is this correct?).



Now I'm having some trouble to conclude that $f$ is bounded.



I would appreciate if someone could help me!










share|cite|improve this question



























    0














    Let $(V, geq)$ be a Banach lattice and $(W, geq)$ be Riesz space whose whose positive cone is generated by some positive element of the space. Then $mathcal{L}(V, W)^+ = mathcal{B}(V, W)^+$, where $mathcal{L}(V, W)^+$, $mathcal{B}(V, W)^+$ are the sets of positive elements of $mathcal{L}(V, W)$ and $mathcal{B}(V, W)$, respectevely.



    Trivially, $mathcal{B}(V, W)^+ subset mathcal{L}(V, W)^+$. So it remains to show that $mathcal{L}(V, W)^+ subset mathcal{B}(V, W)^+$, which means that every positive linear functional between $V$ and $W$ is bounded.



    Let $fcolon V rightarrow W in mathcal{L}(V, W)^+$.Thus, by definition, $f(v) geq 0$ if $v geq 0$.



    So, for $v geq 0$, we have that $f(v) in W^+$, which is generated by some positive element of $W$. Formally, there is $w_0$ such that $W^+ = cup_{alpha in mathbb{R}^+_0} [0, alpha w_0]$.



    Then, there is $beta in mathbb{R}^+_0$ such that $f(v) = beta w_0$ (is this correct?).



    Now I'm having some trouble to conclude that $f$ is bounded.



    I would appreciate if someone could help me!










    share|cite|improve this question

























      0












      0








      0







      Let $(V, geq)$ be a Banach lattice and $(W, geq)$ be Riesz space whose whose positive cone is generated by some positive element of the space. Then $mathcal{L}(V, W)^+ = mathcal{B}(V, W)^+$, where $mathcal{L}(V, W)^+$, $mathcal{B}(V, W)^+$ are the sets of positive elements of $mathcal{L}(V, W)$ and $mathcal{B}(V, W)$, respectevely.



      Trivially, $mathcal{B}(V, W)^+ subset mathcal{L}(V, W)^+$. So it remains to show that $mathcal{L}(V, W)^+ subset mathcal{B}(V, W)^+$, which means that every positive linear functional between $V$ and $W$ is bounded.



      Let $fcolon V rightarrow W in mathcal{L}(V, W)^+$.Thus, by definition, $f(v) geq 0$ if $v geq 0$.



      So, for $v geq 0$, we have that $f(v) in W^+$, which is generated by some positive element of $W$. Formally, there is $w_0$ such that $W^+ = cup_{alpha in mathbb{R}^+_0} [0, alpha w_0]$.



      Then, there is $beta in mathbb{R}^+_0$ such that $f(v) = beta w_0$ (is this correct?).



      Now I'm having some trouble to conclude that $f$ is bounded.



      I would appreciate if someone could help me!










      share|cite|improve this question













      Let $(V, geq)$ be a Banach lattice and $(W, geq)$ be Riesz space whose whose positive cone is generated by some positive element of the space. Then $mathcal{L}(V, W)^+ = mathcal{B}(V, W)^+$, where $mathcal{L}(V, W)^+$, $mathcal{B}(V, W)^+$ are the sets of positive elements of $mathcal{L}(V, W)$ and $mathcal{B}(V, W)$, respectevely.



      Trivially, $mathcal{B}(V, W)^+ subset mathcal{L}(V, W)^+$. So it remains to show that $mathcal{L}(V, W)^+ subset mathcal{B}(V, W)^+$, which means that every positive linear functional between $V$ and $W$ is bounded.



      Let $fcolon V rightarrow W in mathcal{L}(V, W)^+$.Thus, by definition, $f(v) geq 0$ if $v geq 0$.



      So, for $v geq 0$, we have that $f(v) in W^+$, which is generated by some positive element of $W$. Formally, there is $w_0$ such that $W^+ = cup_{alpha in mathbb{R}^+_0} [0, alpha w_0]$.



      Then, there is $beta in mathbb{R}^+_0$ such that $f(v) = beta w_0$ (is this correct?).



      Now I'm having some trouble to conclude that $f$ is bounded.



      I would appreciate if someone could help me!







      banach-spaces lattice-orders banach-lattices






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Nov 24 at 17:38









      Luísa Borsato

      1,496315




      1,496315



























          active

          oldest

          votes











          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',
          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%2f3011844%2fv-geq-banach-lattice-w-geq-riesz-space-then-mathcallv-w%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown






























          active

          oldest

          votes













          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes
















          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.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • 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.


          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%2f3011844%2fv-geq-banach-lattice-w-geq-riesz-space-then-mathcallv-w%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

          Plaza Victoria

          Puebla de Zaragoza

          Musa