Are there $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} setminus C_{10})$ in $K_{11,11}$?












7












$begingroup$


Question: Are there $3$ edge disjoint copies of $H:=2K_{3,3} cup (K_{5,5} setminus C_{10})$ in $K_{11,11}$?



Here's a drawing of $H$:



$2K_{3,3} cup (K_{5,5} setminus C_{10})$



I'm working on a Latin squares research problem and trying to get a construction to work. If it would work, it would give a solution to this problem. Only, I can't get it to work easily. Maybe the above doesn't exist, and my construction won't work in this case.




  • We see $H$ is regular with degree $3$, and the degrees of vertices in $K_{11,11}$ is $11$, so no clash there.

  • $H$ has $33$ edges while $K_{11,11}$ has $121$ edges, so no clash there.










share|cite|improve this question











$endgroup$

















    7












    $begingroup$


    Question: Are there $3$ edge disjoint copies of $H:=2K_{3,3} cup (K_{5,5} setminus C_{10})$ in $K_{11,11}$?



    Here's a drawing of $H$:



    $2K_{3,3} cup (K_{5,5} setminus C_{10})$



    I'm working on a Latin squares research problem and trying to get a construction to work. If it would work, it would give a solution to this problem. Only, I can't get it to work easily. Maybe the above doesn't exist, and my construction won't work in this case.




    • We see $H$ is regular with degree $3$, and the degrees of vertices in $K_{11,11}$ is $11$, so no clash there.

    • $H$ has $33$ edges while $K_{11,11}$ has $121$ edges, so no clash there.










    share|cite|improve this question











    $endgroup$















      7












      7








      7


      3



      $begingroup$


      Question: Are there $3$ edge disjoint copies of $H:=2K_{3,3} cup (K_{5,5} setminus C_{10})$ in $K_{11,11}$?



      Here's a drawing of $H$:



      $2K_{3,3} cup (K_{5,5} setminus C_{10})$



      I'm working on a Latin squares research problem and trying to get a construction to work. If it would work, it would give a solution to this problem. Only, I can't get it to work easily. Maybe the above doesn't exist, and my construction won't work in this case.




      • We see $H$ is regular with degree $3$, and the degrees of vertices in $K_{11,11}$ is $11$, so no clash there.

      • $H$ has $33$ edges while $K_{11,11}$ has $121$ edges, so no clash there.










      share|cite|improve this question











      $endgroup$




      Question: Are there $3$ edge disjoint copies of $H:=2K_{3,3} cup (K_{5,5} setminus C_{10})$ in $K_{11,11}$?



      Here's a drawing of $H$:



      $2K_{3,3} cup (K_{5,5} setminus C_{10})$



      I'm working on a Latin squares research problem and trying to get a construction to work. If it would work, it would give a solution to this problem. Only, I can't get it to work easily. Maybe the above doesn't exist, and my construction won't work in this case.




      • We see $H$ is regular with degree $3$, and the degrees of vertices in $K_{11,11}$ is $11$, so no clash there.

      • $H$ has $33$ edges while $K_{11,11}$ has $121$ edges, so no clash there.







      graph-theory






      share|cite|improve this question















      share|cite|improve this question













      share|cite|improve this question




      share|cite|improve this question








      edited Jan 13 '17 at 14:25









      Ethan Bolker

      42.7k549113




      42.7k549113










      asked Jan 13 '17 at 14:21









      Rebecca J. StonesRebecca J. Stones

      20.9k22781




      20.9k22781






















          1 Answer
          1






          active

          oldest

          votes


















          3












          $begingroup$

          Since I solved the other linked problem, I figured I might as well give simulated annealing a go on this one.



          The answer is also yes; in fact, here, we can find $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} - P_{10})$. I added the extra edge in an attempt to make the problem a bit more constrained so that the solution would come out nicer, but I'm not sure how much of an effect it had.



          The solution I found is below:



          enter image description here



          Here is my simulated annealing code (it might take a few tries before finding a zero-energy solution):



          edges[{perm1_, perm2_}] :=
          Join[
          Tuples[{perm1[[1 ;; 3]], perm2[[1 ;; 3]]}],
          Tuples[{perm1[[4 ;; 6]], perm2[[4 ;; 6]]}],
          Complement[
          Tuples[{perm1[[7 ;; 11]], perm2[[7 ;; 11]]}],
          Table[{perm1[[i]], perm2[[i]]}, {i, 7, 11}],
          Table[{perm1[[i]], perm2[[i + 1]]}, {i, 7, 10}]]];
          value[state_] := 102 - Length[Union @@ (edges /@ state)];
          randomPerm := {RandomSample[Range[11]], RandomSample[Range[11]]}
          newState := {{Range[11], Range[11]}, randomPerm, randomPerm};
          randomSwitch[state_] :=
          Module[{h = RandomInteger[{2, 3}], i = RandomInteger[{1, 2}], j, k,
          copy = state},
          {j, k} = RandomSample[Range[11], 2];
          copy[[h, i, {j, k}]] = Reverse[copy[[h, i, {j, k}]]];
          Return[copy];
          ]

          currentState = bestState = newState;
          currentEnergy = bestEnergy = value[currentState];
          temp = 1;
          While[Exp[-1/temp] > 1/1000,
          Do[
          nextState = randomSwitch[currentState];
          nextEnergy = value[nextState];
          If[nextEnergy < bestEnergy, bestState = nextState;
          bestEnergy = nextEnergy];
          prob = Exp[-((nextEnergy - currentEnergy)/temp)];
          If[RandomReal < prob, currentState = nextState;
          currentEnergy = nextEnergy];
          , {3000}];
          If[bestEnergy == 0, Break];
          temp *= 0.99; Print[{temp, currentEnergy}]
          ]
          Print["Done ", bestEnergy];





          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%2f2096176%2fare-there-3-disjoint-copies-of-2k-3-3-cup-k-5-5-setminus-c-10-in%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









            3












            $begingroup$

            Since I solved the other linked problem, I figured I might as well give simulated annealing a go on this one.



            The answer is also yes; in fact, here, we can find $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} - P_{10})$. I added the extra edge in an attempt to make the problem a bit more constrained so that the solution would come out nicer, but I'm not sure how much of an effect it had.



            The solution I found is below:



            enter image description here



            Here is my simulated annealing code (it might take a few tries before finding a zero-energy solution):



            edges[{perm1_, perm2_}] :=
            Join[
            Tuples[{perm1[[1 ;; 3]], perm2[[1 ;; 3]]}],
            Tuples[{perm1[[4 ;; 6]], perm2[[4 ;; 6]]}],
            Complement[
            Tuples[{perm1[[7 ;; 11]], perm2[[7 ;; 11]]}],
            Table[{perm1[[i]], perm2[[i]]}, {i, 7, 11}],
            Table[{perm1[[i]], perm2[[i + 1]]}, {i, 7, 10}]]];
            value[state_] := 102 - Length[Union @@ (edges /@ state)];
            randomPerm := {RandomSample[Range[11]], RandomSample[Range[11]]}
            newState := {{Range[11], Range[11]}, randomPerm, randomPerm};
            randomSwitch[state_] :=
            Module[{h = RandomInteger[{2, 3}], i = RandomInteger[{1, 2}], j, k,
            copy = state},
            {j, k} = RandomSample[Range[11], 2];
            copy[[h, i, {j, k}]] = Reverse[copy[[h, i, {j, k}]]];
            Return[copy];
            ]

            currentState = bestState = newState;
            currentEnergy = bestEnergy = value[currentState];
            temp = 1;
            While[Exp[-1/temp] > 1/1000,
            Do[
            nextState = randomSwitch[currentState];
            nextEnergy = value[nextState];
            If[nextEnergy < bestEnergy, bestState = nextState;
            bestEnergy = nextEnergy];
            prob = Exp[-((nextEnergy - currentEnergy)/temp)];
            If[RandomReal < prob, currentState = nextState;
            currentEnergy = nextEnergy];
            , {3000}];
            If[bestEnergy == 0, Break];
            temp *= 0.99; Print[{temp, currentEnergy}]
            ]
            Print["Done ", bestEnergy];





            share|cite|improve this answer









            $endgroup$


















              3












              $begingroup$

              Since I solved the other linked problem, I figured I might as well give simulated annealing a go on this one.



              The answer is also yes; in fact, here, we can find $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} - P_{10})$. I added the extra edge in an attempt to make the problem a bit more constrained so that the solution would come out nicer, but I'm not sure how much of an effect it had.



              The solution I found is below:



              enter image description here



              Here is my simulated annealing code (it might take a few tries before finding a zero-energy solution):



              edges[{perm1_, perm2_}] :=
              Join[
              Tuples[{perm1[[1 ;; 3]], perm2[[1 ;; 3]]}],
              Tuples[{perm1[[4 ;; 6]], perm2[[4 ;; 6]]}],
              Complement[
              Tuples[{perm1[[7 ;; 11]], perm2[[7 ;; 11]]}],
              Table[{perm1[[i]], perm2[[i]]}, {i, 7, 11}],
              Table[{perm1[[i]], perm2[[i + 1]]}, {i, 7, 10}]]];
              value[state_] := 102 - Length[Union @@ (edges /@ state)];
              randomPerm := {RandomSample[Range[11]], RandomSample[Range[11]]}
              newState := {{Range[11], Range[11]}, randomPerm, randomPerm};
              randomSwitch[state_] :=
              Module[{h = RandomInteger[{2, 3}], i = RandomInteger[{1, 2}], j, k,
              copy = state},
              {j, k} = RandomSample[Range[11], 2];
              copy[[h, i, {j, k}]] = Reverse[copy[[h, i, {j, k}]]];
              Return[copy];
              ]

              currentState = bestState = newState;
              currentEnergy = bestEnergy = value[currentState];
              temp = 1;
              While[Exp[-1/temp] > 1/1000,
              Do[
              nextState = randomSwitch[currentState];
              nextEnergy = value[nextState];
              If[nextEnergy < bestEnergy, bestState = nextState;
              bestEnergy = nextEnergy];
              prob = Exp[-((nextEnergy - currentEnergy)/temp)];
              If[RandomReal < prob, currentState = nextState;
              currentEnergy = nextEnergy];
              , {3000}];
              If[bestEnergy == 0, Break];
              temp *= 0.99; Print[{temp, currentEnergy}]
              ]
              Print["Done ", bestEnergy];





              share|cite|improve this answer









              $endgroup$
















                3












                3








                3





                $begingroup$

                Since I solved the other linked problem, I figured I might as well give simulated annealing a go on this one.



                The answer is also yes; in fact, here, we can find $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} - P_{10})$. I added the extra edge in an attempt to make the problem a bit more constrained so that the solution would come out nicer, but I'm not sure how much of an effect it had.



                The solution I found is below:



                enter image description here



                Here is my simulated annealing code (it might take a few tries before finding a zero-energy solution):



                edges[{perm1_, perm2_}] :=
                Join[
                Tuples[{perm1[[1 ;; 3]], perm2[[1 ;; 3]]}],
                Tuples[{perm1[[4 ;; 6]], perm2[[4 ;; 6]]}],
                Complement[
                Tuples[{perm1[[7 ;; 11]], perm2[[7 ;; 11]]}],
                Table[{perm1[[i]], perm2[[i]]}, {i, 7, 11}],
                Table[{perm1[[i]], perm2[[i + 1]]}, {i, 7, 10}]]];
                value[state_] := 102 - Length[Union @@ (edges /@ state)];
                randomPerm := {RandomSample[Range[11]], RandomSample[Range[11]]}
                newState := {{Range[11], Range[11]}, randomPerm, randomPerm};
                randomSwitch[state_] :=
                Module[{h = RandomInteger[{2, 3}], i = RandomInteger[{1, 2}], j, k,
                copy = state},
                {j, k} = RandomSample[Range[11], 2];
                copy[[h, i, {j, k}]] = Reverse[copy[[h, i, {j, k}]]];
                Return[copy];
                ]

                currentState = bestState = newState;
                currentEnergy = bestEnergy = value[currentState];
                temp = 1;
                While[Exp[-1/temp] > 1/1000,
                Do[
                nextState = randomSwitch[currentState];
                nextEnergy = value[nextState];
                If[nextEnergy < bestEnergy, bestState = nextState;
                bestEnergy = nextEnergy];
                prob = Exp[-((nextEnergy - currentEnergy)/temp)];
                If[RandomReal < prob, currentState = nextState;
                currentEnergy = nextEnergy];
                , {3000}];
                If[bestEnergy == 0, Break];
                temp *= 0.99; Print[{temp, currentEnergy}]
                ]
                Print["Done ", bestEnergy];





                share|cite|improve this answer









                $endgroup$



                Since I solved the other linked problem, I figured I might as well give simulated annealing a go on this one.



                The answer is also yes; in fact, here, we can find $3$ disjoint copies of $2K_{3,3} cup (K_{5,5} - P_{10})$. I added the extra edge in an attempt to make the problem a bit more constrained so that the solution would come out nicer, but I'm not sure how much of an effect it had.



                The solution I found is below:



                enter image description here



                Here is my simulated annealing code (it might take a few tries before finding a zero-energy solution):



                edges[{perm1_, perm2_}] :=
                Join[
                Tuples[{perm1[[1 ;; 3]], perm2[[1 ;; 3]]}],
                Tuples[{perm1[[4 ;; 6]], perm2[[4 ;; 6]]}],
                Complement[
                Tuples[{perm1[[7 ;; 11]], perm2[[7 ;; 11]]}],
                Table[{perm1[[i]], perm2[[i]]}, {i, 7, 11}],
                Table[{perm1[[i]], perm2[[i + 1]]}, {i, 7, 10}]]];
                value[state_] := 102 - Length[Union @@ (edges /@ state)];
                randomPerm := {RandomSample[Range[11]], RandomSample[Range[11]]}
                newState := {{Range[11], Range[11]}, randomPerm, randomPerm};
                randomSwitch[state_] :=
                Module[{h = RandomInteger[{2, 3}], i = RandomInteger[{1, 2}], j, k,
                copy = state},
                {j, k} = RandomSample[Range[11], 2];
                copy[[h, i, {j, k}]] = Reverse[copy[[h, i, {j, k}]]];
                Return[copy];
                ]

                currentState = bestState = newState;
                currentEnergy = bestEnergy = value[currentState];
                temp = 1;
                While[Exp[-1/temp] > 1/1000,
                Do[
                nextState = randomSwitch[currentState];
                nextEnergy = value[nextState];
                If[nextEnergy < bestEnergy, bestState = nextState;
                bestEnergy = nextEnergy];
                prob = Exp[-((nextEnergy - currentEnergy)/temp)];
                If[RandomReal < prob, currentState = nextState;
                currentEnergy = nextEnergy];
                , {3000}];
                If[bestEnergy == 0, Break];
                temp *= 0.99; Print[{temp, currentEnergy}]
                ]
                Print["Done ", bestEnergy];






                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Dec 14 '18 at 19:18









                Misha LavrovMisha Lavrov

                46.1k656107




                46.1k656107






























                    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%2f2096176%2fare-there-3-disjoint-copies-of-2k-3-3-cup-k-5-5-setminus-c-10-in%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

                    Ellipse (mathématiques)

                    Quarter-circle Tiles

                    Mont Emei