Is there a way to make two different adjacency matrices (same size) have the same degree matrix?

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For the same set of vertices, there are two different topologies and edge weights. Therefore, we have two different adjacency matrices for the same vertices. Is it possible to make those two different adjacency matrices have the same degree matrix?







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  • By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
    – Parcly Taxel
    Jul 24 at 15:42










  • @ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
    – E.J.
    Jul 24 at 15:46










  • The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
    – Parcly Taxel
    Jul 24 at 15:50














up vote
1
down vote

favorite












For the same set of vertices, there are two different topologies and edge weights. Therefore, we have two different adjacency matrices for the same vertices. Is it possible to make those two different adjacency matrices have the same degree matrix?







share|cite|improve this question





















  • By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
    – Parcly Taxel
    Jul 24 at 15:42










  • @ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
    – E.J.
    Jul 24 at 15:46










  • The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
    – Parcly Taxel
    Jul 24 at 15:50












up vote
1
down vote

favorite









up vote
1
down vote

favorite











For the same set of vertices, there are two different topologies and edge weights. Therefore, we have two different adjacency matrices for the same vertices. Is it possible to make those two different adjacency matrices have the same degree matrix?







share|cite|improve this question













For the same set of vertices, there are two different topologies and edge weights. Therefore, we have two different adjacency matrices for the same vertices. Is it possible to make those two different adjacency matrices have the same degree matrix?









share|cite|improve this question












share|cite|improve this question




share|cite|improve this question








edited Jul 26 at 15:38
























asked Jul 24 at 15:38









E.J.

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  • By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
    – Parcly Taxel
    Jul 24 at 15:42










  • @ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
    – E.J.
    Jul 24 at 15:46










  • The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
    – Parcly Taxel
    Jul 24 at 15:50
















  • By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
    – Parcly Taxel
    Jul 24 at 15:42










  • @ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
    – E.J.
    Jul 24 at 15:46










  • The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
    – Parcly Taxel
    Jul 24 at 15:50















By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
– Parcly Taxel
Jul 24 at 15:42




By "degree matrix" you mean degree sequence? If so, then yes, we can take the graphs of the pentagonal prism and Petersen's graph.
– Parcly Taxel
Jul 24 at 15:42












@ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
– E.J.
Jul 24 at 15:46




@ParclyTaxel The definition of "degree matrix" is here en.wikipedia.org/wiki/Degree_matrix. Can you specify how to do that or any references?
– E.J.
Jul 24 at 15:46












The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
– Parcly Taxel
Jul 24 at 15:50




The degree matrix is a diagonal matrix and its diagonal forms the degree sequence.
– Parcly Taxel
Jul 24 at 15:50










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It is certainly possible. Note that the idea of a degree matrix can be represented more concisely by a degree sequence, since a degree matrix is diagonal.



For an explicit example of two graphs with different adjacency matrices but the same degree matrix, consider:



  • the 1-skeleton of the pentagonal prism (its vertices and edges), which has girth 4

  • the Petersen graph of girth 5

Both of them have different adjacency matrices, but the same degree matrix of three times the identity matrix of size 10 (i.e. a degree sequence of ten threes).






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    1 Answer
    1






    active

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    1 Answer
    1






    active

    oldest

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    active

    oldest

    votes








    up vote
    3
    down vote













    It is certainly possible. Note that the idea of a degree matrix can be represented more concisely by a degree sequence, since a degree matrix is diagonal.



    For an explicit example of two graphs with different adjacency matrices but the same degree matrix, consider:



    • the 1-skeleton of the pentagonal prism (its vertices and edges), which has girth 4

    • the Petersen graph of girth 5

    Both of them have different adjacency matrices, but the same degree matrix of three times the identity matrix of size 10 (i.e. a degree sequence of ten threes).






    share|cite|improve this answer

























      up vote
      3
      down vote













      It is certainly possible. Note that the idea of a degree matrix can be represented more concisely by a degree sequence, since a degree matrix is diagonal.



      For an explicit example of two graphs with different adjacency matrices but the same degree matrix, consider:



      • the 1-skeleton of the pentagonal prism (its vertices and edges), which has girth 4

      • the Petersen graph of girth 5

      Both of them have different adjacency matrices, but the same degree matrix of three times the identity matrix of size 10 (i.e. a degree sequence of ten threes).






      share|cite|improve this answer























        up vote
        3
        down vote










        up vote
        3
        down vote









        It is certainly possible. Note that the idea of a degree matrix can be represented more concisely by a degree sequence, since a degree matrix is diagonal.



        For an explicit example of two graphs with different adjacency matrices but the same degree matrix, consider:



        • the 1-skeleton of the pentagonal prism (its vertices and edges), which has girth 4

        • the Petersen graph of girth 5

        Both of them have different adjacency matrices, but the same degree matrix of three times the identity matrix of size 10 (i.e. a degree sequence of ten threes).






        share|cite|improve this answer













        It is certainly possible. Note that the idea of a degree matrix can be represented more concisely by a degree sequence, since a degree matrix is diagonal.



        For an explicit example of two graphs with different adjacency matrices but the same degree matrix, consider:



        • the 1-skeleton of the pentagonal prism (its vertices and edges), which has girth 4

        • the Petersen graph of girth 5

        Both of them have different adjacency matrices, but the same degree matrix of three times the identity matrix of size 10 (i.e. a degree sequence of ten threes).







        share|cite|improve this answer













        share|cite|improve this answer



        share|cite|improve this answer











        answered Jul 24 at 15:51









        Parcly Taxel

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