probability of wiring sequence and conditional expectations in random configuration graph












0












$begingroup$


I am reading about the Bollobas Configuration random graph and try to understand the proof of following Proposition:



(see Prop 2.1 in https://arxiv.org/pdf/1512.03084.pdf, page 7-8)



Proposition:
Considering the last step of the ACG construction for finite $N$ with probabilities $P,Q$ conditioned on the $X$ from the first step, one has




  • The conditional probability of any wiring sequence $W=(l in [E])$ is:
    $$ mathbb{P}(W mid X)= C^{-1} prod_{kj} (Q_{kj})^{e_{kj}(W)},$$
    $$C = E! sum_e prod_{kj} frac{(Qkj)^{e_{kj}}}{e_{kj}!} prod_j ({e_j}^-!) prod_k ({e_k}^+ !)$$
    and where the sum above runs over all collections $e=(e_{kj})$ satisfying
    $${e_k}^+ = sum_{j} e_{kj}, quad {e_j}^- = sum_{k}e_{kj}, quad E= sum_{kj}e_{kj}$$


  • The conditional probability of any edge of the wiring sequence $W$ having type $(k, j)$ is
    $$p = mathbb{E}[e_{kj} mid X]/E$$



I don't understand how they prove the very first formula as they simply just state that



The denominator of it is $C = sum_{σ,σ ̃in S(E)} prod_{ l∈[E]} Q_{k_{σ(l)} j_{σ ̃(l)}}$ , from which the formula of $C$ can be verified by induction on $E$.
How do they get to this expression?










share|cite|improve this question









$endgroup$

















    0












    $begingroup$


    I am reading about the Bollobas Configuration random graph and try to understand the proof of following Proposition:



    (see Prop 2.1 in https://arxiv.org/pdf/1512.03084.pdf, page 7-8)



    Proposition:
    Considering the last step of the ACG construction for finite $N$ with probabilities $P,Q$ conditioned on the $X$ from the first step, one has




    • The conditional probability of any wiring sequence $W=(l in [E])$ is:
      $$ mathbb{P}(W mid X)= C^{-1} prod_{kj} (Q_{kj})^{e_{kj}(W)},$$
      $$C = E! sum_e prod_{kj} frac{(Qkj)^{e_{kj}}}{e_{kj}!} prod_j ({e_j}^-!) prod_k ({e_k}^+ !)$$
      and where the sum above runs over all collections $e=(e_{kj})$ satisfying
      $${e_k}^+ = sum_{j} e_{kj}, quad {e_j}^- = sum_{k}e_{kj}, quad E= sum_{kj}e_{kj}$$


    • The conditional probability of any edge of the wiring sequence $W$ having type $(k, j)$ is
      $$p = mathbb{E}[e_{kj} mid X]/E$$



    I don't understand how they prove the very first formula as they simply just state that



    The denominator of it is $C = sum_{σ,σ ̃in S(E)} prod_{ l∈[E]} Q_{k_{σ(l)} j_{σ ̃(l)}}$ , from which the formula of $C$ can be verified by induction on $E$.
    How do they get to this expression?










    share|cite|improve this question









    $endgroup$















      0












      0








      0





      $begingroup$


      I am reading about the Bollobas Configuration random graph and try to understand the proof of following Proposition:



      (see Prop 2.1 in https://arxiv.org/pdf/1512.03084.pdf, page 7-8)



      Proposition:
      Considering the last step of the ACG construction for finite $N$ with probabilities $P,Q$ conditioned on the $X$ from the first step, one has




      • The conditional probability of any wiring sequence $W=(l in [E])$ is:
        $$ mathbb{P}(W mid X)= C^{-1} prod_{kj} (Q_{kj})^{e_{kj}(W)},$$
        $$C = E! sum_e prod_{kj} frac{(Qkj)^{e_{kj}}}{e_{kj}!} prod_j ({e_j}^-!) prod_k ({e_k}^+ !)$$
        and where the sum above runs over all collections $e=(e_{kj})$ satisfying
        $${e_k}^+ = sum_{j} e_{kj}, quad {e_j}^- = sum_{k}e_{kj}, quad E= sum_{kj}e_{kj}$$


      • The conditional probability of any edge of the wiring sequence $W$ having type $(k, j)$ is
        $$p = mathbb{E}[e_{kj} mid X]/E$$



      I don't understand how they prove the very first formula as they simply just state that



      The denominator of it is $C = sum_{σ,σ ̃in S(E)} prod_{ l∈[E]} Q_{k_{σ(l)} j_{σ ̃(l)}}$ , from which the formula of $C$ can be verified by induction on $E$.
      How do they get to this expression?










      share|cite|improve this question









      $endgroup$




      I am reading about the Bollobas Configuration random graph and try to understand the proof of following Proposition:



      (see Prop 2.1 in https://arxiv.org/pdf/1512.03084.pdf, page 7-8)



      Proposition:
      Considering the last step of the ACG construction for finite $N$ with probabilities $P,Q$ conditioned on the $X$ from the first step, one has




      • The conditional probability of any wiring sequence $W=(l in [E])$ is:
        $$ mathbb{P}(W mid X)= C^{-1} prod_{kj} (Q_{kj})^{e_{kj}(W)},$$
        $$C = E! sum_e prod_{kj} frac{(Qkj)^{e_{kj}}}{e_{kj}!} prod_j ({e_j}^-!) prod_k ({e_k}^+ !)$$
        and where the sum above runs over all collections $e=(e_{kj})$ satisfying
        $${e_k}^+ = sum_{j} e_{kj}, quad {e_j}^- = sum_{k}e_{kj}, quad E= sum_{kj}e_{kj}$$


      • The conditional probability of any edge of the wiring sequence $W$ having type $(k, j)$ is
        $$p = mathbb{E}[e_{kj} mid X]/E$$



      I don't understand how they prove the very first formula as they simply just state that



      The denominator of it is $C = sum_{σ,σ ̃in S(E)} prod_{ l∈[E]} Q_{k_{σ(l)} j_{σ ̃(l)}}$ , from which the formula of $C$ can be verified by induction on $E$.
      How do they get to this expression?







      probability graph-theory random-graphs






      share|cite|improve this question













      share|cite|improve this question











      share|cite|improve this question




      share|cite|improve this question










      asked Dec 23 '18 at 14:18









      AlisatAlisat

      448




      448






















          0






          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%2f3050375%2fprobability-of-wiring-sequence-and-conditional-expectations-in-random-configurat%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          0






          active

          oldest

          votes








          0






          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.




          draft saved


          draft discarded














          StackExchange.ready(
          function () {
          StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3050375%2fprobability-of-wiring-sequence-and-conditional-expectations-in-random-configurat%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

          Bressuire

          Cabo Verde

          Gyllenstierna