$2$-factorizations of a $4$-regular graph












1












$begingroup$


Suppose there is a $4$ regular graph. Then it has $2$ edge disjoint $2$-regular spanning subgraphs. Let the spanning subgraphs be $T_1$ and $T_2$. Can there be another pair $T_3$ and $T_4$ of edge disjoint $2$-regular spanning subgraphs for the same graph? I mean that can we regard the existance of two edge disjoint $2$-regular spanning subgraphs as a unique existance?










share|cite|improve this question











$endgroup$

















    1












    $begingroup$


    Suppose there is a $4$ regular graph. Then it has $2$ edge disjoint $2$-regular spanning subgraphs. Let the spanning subgraphs be $T_1$ and $T_2$. Can there be another pair $T_3$ and $T_4$ of edge disjoint $2$-regular spanning subgraphs for the same graph? I mean that can we regard the existance of two edge disjoint $2$-regular spanning subgraphs as a unique existance?










    share|cite|improve this question











    $endgroup$















      1












      1








      1





      $begingroup$


      Suppose there is a $4$ regular graph. Then it has $2$ edge disjoint $2$-regular spanning subgraphs. Let the spanning subgraphs be $T_1$ and $T_2$. Can there be another pair $T_3$ and $T_4$ of edge disjoint $2$-regular spanning subgraphs for the same graph? I mean that can we regard the existance of two edge disjoint $2$-regular spanning subgraphs as a unique existance?










      share|cite|improve this question











      $endgroup$




      Suppose there is a $4$ regular graph. Then it has $2$ edge disjoint $2$-regular spanning subgraphs. Let the spanning subgraphs be $T_1$ and $T_2$. Can there be another pair $T_3$ and $T_4$ of edge disjoint $2$-regular spanning subgraphs for the same graph? I mean that can we regard the existance of two edge disjoint $2$-regular spanning subgraphs as a unique existance?







      graph-theory finite-groups






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Dec 3 '18 at 9:22









      Tianlalu

      3,08621038




      3,08621038










      asked Dec 3 '18 at 5:39









      Buddhini AngelikaBuddhini Angelika

      15710




      15710






















          1 Answer
          1






          active

          oldest

          votes


















          1












          $begingroup$

          Take $K_5$, the complete graph on $5$ vertices. Any cycle containing every vertex (Hamiltonian cycle if you are familiar with the terminology) and its complement exactly act as you describe. This graph contains more than $2$ Hamiltonian cycles, so this decomposition is not unique. Explicitly, if we take the vertices to be ${a,b,c,d,e}$, the decomposition into cycles $a-b-c-d-e-a$ and $a-c-e-b-d-a$ is distinct from the decomposition into $a-b-d-e-c-a$ and $a-d-c-b-e-a$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thanks a lot @platty
            $endgroup$
            – Buddhini Angelika
            Dec 3 '18 at 8:24











          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%2f3023689%2f2-factorizations-of-a-4-regular-graph%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1












          $begingroup$

          Take $K_5$, the complete graph on $5$ vertices. Any cycle containing every vertex (Hamiltonian cycle if you are familiar with the terminology) and its complement exactly act as you describe. This graph contains more than $2$ Hamiltonian cycles, so this decomposition is not unique. Explicitly, if we take the vertices to be ${a,b,c,d,e}$, the decomposition into cycles $a-b-c-d-e-a$ and $a-c-e-b-d-a$ is distinct from the decomposition into $a-b-d-e-c-a$ and $a-d-c-b-e-a$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thanks a lot @platty
            $endgroup$
            – Buddhini Angelika
            Dec 3 '18 at 8:24
















          1












          $begingroup$

          Take $K_5$, the complete graph on $5$ vertices. Any cycle containing every vertex (Hamiltonian cycle if you are familiar with the terminology) and its complement exactly act as you describe. This graph contains more than $2$ Hamiltonian cycles, so this decomposition is not unique. Explicitly, if we take the vertices to be ${a,b,c,d,e}$, the decomposition into cycles $a-b-c-d-e-a$ and $a-c-e-b-d-a$ is distinct from the decomposition into $a-b-d-e-c-a$ and $a-d-c-b-e-a$.






          share|cite|improve this answer









          $endgroup$













          • $begingroup$
            Thanks a lot @platty
            $endgroup$
            – Buddhini Angelika
            Dec 3 '18 at 8:24














          1












          1








          1





          $begingroup$

          Take $K_5$, the complete graph on $5$ vertices. Any cycle containing every vertex (Hamiltonian cycle if you are familiar with the terminology) and its complement exactly act as you describe. This graph contains more than $2$ Hamiltonian cycles, so this decomposition is not unique. Explicitly, if we take the vertices to be ${a,b,c,d,e}$, the decomposition into cycles $a-b-c-d-e-a$ and $a-c-e-b-d-a$ is distinct from the decomposition into $a-b-d-e-c-a$ and $a-d-c-b-e-a$.






          share|cite|improve this answer









          $endgroup$



          Take $K_5$, the complete graph on $5$ vertices. Any cycle containing every vertex (Hamiltonian cycle if you are familiar with the terminology) and its complement exactly act as you describe. This graph contains more than $2$ Hamiltonian cycles, so this decomposition is not unique. Explicitly, if we take the vertices to be ${a,b,c,d,e}$, the decomposition into cycles $a-b-c-d-e-a$ and $a-c-e-b-d-a$ is distinct from the decomposition into $a-b-d-e-c-a$ and $a-d-c-b-e-a$.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered Dec 3 '18 at 5:53









          plattyplatty

          3,370320




          3,370320












          • $begingroup$
            Thanks a lot @platty
            $endgroup$
            – Buddhini Angelika
            Dec 3 '18 at 8:24


















          • $begingroup$
            Thanks a lot @platty
            $endgroup$
            – Buddhini Angelika
            Dec 3 '18 at 8:24
















          $begingroup$
          Thanks a lot @platty
          $endgroup$
          – Buddhini Angelika
          Dec 3 '18 at 8:24




          $begingroup$
          Thanks a lot @platty
          $endgroup$
          – Buddhini Angelika
          Dec 3 '18 at 8:24


















          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%2f3023689%2f2-factorizations-of-a-4-regular-graph%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