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

Have any astronauts/cosmonauts died in space?

Why is this tree refusing to shed its dead leaves?

Why didn’t Eve recognize the little cockroach as a living organism?

Is VPN a layer 3 concept?

Turning a hard to access nut?

Why is participating in the European Parliamentary elections used as a threat?

Does convergence of polynomials imply that of its coefficients?

How to test the sharpness of a knife?

PTIJ: Which Dr. Seuss books should one obtain?

Air travel with refrigerated insulin

Have the tides ever turned twice on any open problem?

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

How to read string as hex number in bash?

Jem'Hadar, something strange about their life expectancy

If I cast enlarge/reduce on an arrow, what weapon could it count as?

What (if any) is the reason to buy in small local stores?

Weird lines in Microsoft Word

Nested Dynamic SOQL Query

"Marked down as someone wanting to sell shares." What does that mean?

Would storms on an ocean world harm the marine life?

Would it be believable to defy demographics in a story?

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

Did Nintendo change its mind about 68000 SNES?

Knife as defense against stray dogs



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 4 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

                              Era Viking Índice Início da Era Viquingue | Cotidiano | Sociedade | Língua | Religião | A arte | As primeiras cidades | As viagens dos viquingues | Viquingues do Oeste e Leste | Fim da Era Viquingue | Fontes históricas | Referências Bibliografia | Ligações externas | Menu de navegação«Sverige då!»«Handel I vikingetid»«O que é Nórdico Antigo»Mito, magia e religião na volsunga saga Um olhar sobre a trajetória mítica do herói sigurd«Bonden var den verklige vikingen»«Vikingatiden»«Vikingatiden»«Vinland»«Guerreiras de Óðinn: As Valkyrjor na Mitologia Viking»1519-9053«Esculpindo símbolos e seres: A arte viking em pedras rúnicas»1679-9313Historia - Tema: VikingarnaAventura e Magia no Mundo das Sagas IslandesasEra Vikinge

                              Metrô de Los Teques Índice Linhas | Estações | Ver também | Referências Ligações externas | Menu de navegação«INSTITUCIÓN»«Mapa de rutas»originalMetrô de Los TequesC.A. Metro Los Teques |Alcaldía de Guaicaipuro – Sitio OficialGobernacion de Mirandaeeeeeee

                              What's the metal clinking sound at the end of credits in Avengers: Endgame?What makes Thanos so strong in Avengers: Endgame?Who is the character that appears at the end of Endgame?What happens to Mjolnir (Thor's hammer) at the end of Endgame?The People's Ages in Avengers: EndgameWhat did Nebula do in Avengers: Endgame?Messing with time in the Avengers: Endgame climaxAvengers: Endgame timelineWhat are the time-travel rules in Avengers Endgame?Why use this song in Avengers: Endgame Opening Logo Sequence?Peggy's age in Avengers Endgame