Is a square zero matrix positive semidefinite?Algorithm for generating positive semidefinite matricesinequality-positive semidefinite matricesProve that every positive semidefinite matrix has nonnegative eigenvaluesEigenvalues and positive semidefiniteness of a special matrixHow to make a matrix positive semidefinite?Singularity positive semidefiniteSemidefinite matrix or indefinite?Can strict positive square matrix contain non zero same eigenvaluesThe square root of a positive semidefinite matrix​Sum of rank 1 positive semidefinite and negative semidefinite matrices

What is it called when someone votes for an option that's not their first choice?

Why is "la Gestapo" feminine?

Are hand made posters acceptable in Academia?

Did Nintendo change its mind about 68000 SNES?

Why do I have a large white artefact on the rendered image?

How can I create URL shortcuts/redirects for task/diff IDs in Phabricator?

Is VPN a layer 3 concept?

Is there any common country to visit for uk and schengen visa?

Is "inadequate referencing" a euphemism for plagiarism?

Should a narrator ever describe things based on a characters view instead of fact?

Can "few" be used as a subject? If so, what is the rule?

Why is indicated airspeed rather than ground speed used during the takeoff roll?

Norwegian Refugee travel document

10 year ban after applying for a UK student visa

Homology of the fiber

Weird lines in Microsoft Word

Don't understand why (5 | -2) > 0 is False where (5 or -2) > 0 is True

What is the tangent at a sharp point on a curve?

Does Shadow Sorcerer's Eyes of the Dark work on all magical darkness or just his/hers?

Do I need to convey a moral for each of my blog post?

Turning a hard to access nut?

Does fire aspect on a sword, destroy mob drops?

Why does Surtur say that Thor is Asgard's doom?

Would mining huge amounts of resources on the Moon change its orbit?



Is a square zero matrix positive semidefinite?


Algorithm for generating positive semidefinite matricesinequality-positive semidefinite matricesProve that every positive semidefinite matrix has nonnegative eigenvaluesEigenvalues and positive semidefiniteness of a special matrixHow to make a matrix positive semidefinite?Singularity positive semidefiniteSemidefinite matrix or indefinite?Can strict positive square matrix contain non zero same eigenvaluesThe square root of a positive semidefinite matrix​Sum of rank 1 positive semidefinite and negative semidefinite matrices













1












$begingroup$


Does the fact that a square zero matrix contains non-negative eigenvalues (zeros) make it proper to say it is positive semidefinite?










share|cite|improve this question











$endgroup$
















    1












    $begingroup$


    Does the fact that a square zero matrix contains non-negative eigenvalues (zeros) make it proper to say it is positive semidefinite?










    share|cite|improve this question











    $endgroup$














      1












      1








      1





      $begingroup$


      Does the fact that a square zero matrix contains non-negative eigenvalues (zeros) make it proper to say it is positive semidefinite?










      share|cite|improve this question











      $endgroup$




      Does the fact that a square zero matrix contains non-negative eigenvalues (zeros) make it proper to say it is positive semidefinite?







      linear-algebra matrices positive-semidefinite






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited 3 hours ago







      Kay

















      asked 4 hours ago









      KayKay

      617




      617




















          2 Answers
          2






          active

          oldest

          votes


















          5












          $begingroup$

          The $n times n$ zero matrix is positive semidefinite and negative semidefinite.






          share|cite|improve this answer









          $endgroup$




















            2












            $begingroup$

            "When in doubt, go back to the basic definitions"! The definition of "positive semi-definite" is "all eigen-values are non-negative". The eigenvalues or the zero matrix are all 0 so, yes, the zero matrix is positive semi-definite. And, as Gary Moon said, it is also negative semi-definite.






            share|cite|improve this answer









            $endgroup$












              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%2f3153187%2fis-a-square-zero-matrix-positive-semidefinite%23new-answer', 'question_page');

              );

              Post as a guest















              Required, but never shown

























              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              5












              $begingroup$

              The $n times n$ zero matrix is positive semidefinite and negative semidefinite.






              share|cite|improve this answer









              $endgroup$

















                5












                $begingroup$

                The $n times n$ zero matrix is positive semidefinite and negative semidefinite.






                share|cite|improve this answer









                $endgroup$















                  5












                  5








                  5





                  $begingroup$

                  The $n times n$ zero matrix is positive semidefinite and negative semidefinite.






                  share|cite|improve this answer









                  $endgroup$



                  The $n times n$ zero matrix is positive semidefinite and negative semidefinite.







                  share|cite|improve this answer












                  share|cite|improve this answer



                  share|cite|improve this answer










                  answered 3 hours ago









                  Gary MoonGary Moon

                  31613




                  31613





















                      2












                      $begingroup$

                      "When in doubt, go back to the basic definitions"! The definition of "positive semi-definite" is "all eigen-values are non-negative". The eigenvalues or the zero matrix are all 0 so, yes, the zero matrix is positive semi-definite. And, as Gary Moon said, it is also negative semi-definite.






                      share|cite|improve this answer









                      $endgroup$

















                        2












                        $begingroup$

                        "When in doubt, go back to the basic definitions"! The definition of "positive semi-definite" is "all eigen-values are non-negative". The eigenvalues or the zero matrix are all 0 so, yes, the zero matrix is positive semi-definite. And, as Gary Moon said, it is also negative semi-definite.






                        share|cite|improve this answer









                        $endgroup$















                          2












                          2








                          2





                          $begingroup$

                          "When in doubt, go back to the basic definitions"! The definition of "positive semi-definite" is "all eigen-values are non-negative". The eigenvalues or the zero matrix are all 0 so, yes, the zero matrix is positive semi-definite. And, as Gary Moon said, it is also negative semi-definite.






                          share|cite|improve this answer









                          $endgroup$



                          "When in doubt, go back to the basic definitions"! The definition of "positive semi-definite" is "all eigen-values are non-negative". The eigenvalues or the zero matrix are all 0 so, yes, the zero matrix is positive semi-definite. And, as Gary Moon said, it is also negative semi-definite.







                          share|cite|improve this answer












                          share|cite|improve this answer



                          share|cite|improve this answer










                          answered 3 hours ago









                          user247327user247327

                          11.4k1516




                          11.4k1516



























                              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.




                              draft saved


                              draft discarded














                              StackExchange.ready(
                              function ()
                              StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3153187%2fis-a-square-zero-matrix-positive-semidefinite%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

                              How should I use the fbox command correctly to avoid producing a Bad Box message?How to put a long piece of text in a box?How to specify height and width of fboxIs there an arrayrulecolor-like command to change the rule color of fbox?What is the command to highlight bad boxes in pdf?Why does fbox sometimes place the box *over* the graphic image?how to put the text in the boxHow to create command for a box where text inside the box can automatically adjust?how can I make an fbox like command with certain color, shape and width of border?how to use fbox in align modeFbox increase the spacing between the box and it content (inner margin)how to change the box height of an equationWhat is the use of the hbox in a newcommand command?

                              152 Atala Notae | Nexus externi | Tabula navigationis"Discovery Circumstances: Numbered Minor Planets"2000152Small-Body Database

                              Doxepinum Nexus interni Notae | Tabula navigationis3158DB01142WHOa682390"Structural Analysis of the Histamine H1 Receptor""Transdermal and Topical Drug Administration in the Treatment of Pain""Antidepressants as antipruritic agents: A review"