Graphs with the same CDC on 8 Vertices
Here we give an exhaustive list of all 32 pairs of non-isomorphic graphs on 8 vertices which have the same CDC. This automatically includes those graphs on ⩽ 8 vertices since any \(n\leqslant8\) vertex pair of graphs \(G\), \(H\) with the same CDC will appear here as the pair \(G+(8-n)K_1\), \(H+(8-n)K_1\). For relevant definitions, please refer to my undergraduate dissertation , or my recent publication with Irene Sciriha.
The numbering of the graphs here is in accordance with the graph data on Brendan McKay's webpage . The colouring of the vertices (and walk matrix rows) is so that vertices of the same colour have the same number of \(k\)-walks, for any value of \(k\).
(447, 958)
(1030, 1162)
(1032, 1164)
(1105, 1235)
(3392, 3494)
(3482, 3592)
(3413, 3779)
(1270, 5629)
(5684, 5718)
(3887, 5753)
(3899, 5755)
(3886, 5756)
(3888, 5759)
(3903, 5761)
(6471, 7012)
(6479, 7013)
(6481, 7015)
(6476, 7026)
(6478, 7028)
(6486, 7035)
(6488, 7037)
(10840, 10851)
(5358, 11716)
(10867, 11731)
(10841, 11742)
(10838, 11747)
(10839, 11748)
(10849, 11751)
(10850, 11752)
(10887, 11755)
(10897, 11761)
(10898, 11762)
It's easy to work with these graphs in Mathematica by importing them from McKay's webpage; the pairs of numbers are available as CSV files from the root directory of this site in the form cdcX.csv
. (X
here stands for the number of vertices; the graphs pairs on this webpage correspond to those in cdc8.csv
). For instance:
I have also computed the pairs for X
=6, 7 and 9, you can see more about those here . Notice that I am making use of the Walks package above.
Ryser Switches
A Ryser switch is a degree-sequence preserving operation on a pair of edges in a given graph. In the list below, it turns out that all but one pair of graphs is the result of a single Ryser switch. (The exceptional pair (5358, 11716) requires two).
Given a graph \(G\) and edges \(uv, xy\in E(G)\) such that \(ux, vy\notin E(G)\), the Ryser switch on the edges \(uv\) and \(xy\) replaces those edges with \(ux\) and \(vy\). We denote the graph obtained by \(\operatorname{ryser}(G,uv,xy)\).
Pair (447, 958)
Graph 447
Graph 958
\(\begin{pmatrix}
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}0\\
\color{blue}1&\color{blue}0\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 447: \(-1\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{2}\)
Eigenvalues of 958: \(-1\), \(-1\), \(-1\), \(-1\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{2}\), \(\boldsymbol{2}\)
CDC
Ryser Switch
\(G_{958}=\operatorname{ryser}(G_{447},16, 38)\)
Pair (1030, 1162)
Graph 1030
Graph 1162
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}5\\
\color{red}1&\color{red}2&\color{red}5\\
\color{blue}1&\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}1&\color{blue}3\\
\color{red}1&\color{red}2&\color{red}5\\
\color{red}1&\color{red}2&\color{red}5\\
\color{green}1&\color{green}3&\color{green}5\\
\color{green}1&\color{green}3&\color{green}5
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 1030: \(-1\), \(-1\), \(\boldsymbol{0.31}\), \(\boldsymbol{0.31}\), \(\boldsymbol{-1.48}\), \(\boldsymbol{-1.48}\), \(\boldsymbol{2.17}\), \(\boldsymbol{2.17}\)
Eigenvalues of 1162: \(-0.31\), \(-1\), \(1\), \(1.48\), \(-2.17\), \(\boldsymbol{0.31}\), \(\boldsymbol{-1.48}\), \(\boldsymbol{2.17}\)
CDC
Ryser Switch
\(G_{1162}=\operatorname{ryser}(G_{1030},15, 26)\)
Pair (1032, 1164)
Graph 1032
Graph 1164
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}5&\color{red}11\\
\color{red}1&\color{red}2&\color{red}5&\color{red}11\\
\color{blue}1&\color{blue}2&\color{blue}6&\color{blue}12\\
\color{green}1&\color{green}0&\color{green}0&\color{green}0\\
\color{red}1&\color{red}2&\color{red}5&\color{red}11\\
\color{red}1&\color{red}2&\color{red}5&\color{red}11\\
\color{yellow}1&\color{yellow}3&\color{yellow}6&\color{yellow}16\\
\color{yellow}1&\color{yellow}3&\color{yellow}6&\color{yellow}16
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 1032: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0}\), \(\boldsymbol{0.47}\), \(\boldsymbol{-1.81}\), \(\boldsymbol{2.34}\)
Eigenvalues of 1164: \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{0.47}\), \(\boldsymbol{-1.81}\), \(\boldsymbol{2.34}\)
CDC
Ryser Switch
\(G_{1164}=\operatorname{ryser}(G_{1032},15, 26)\)
Pair (1105, 1235)
Graph 1105
Graph 1235
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}6\\
\color{red}1&\color{red}2&\color{red}6\\
\color{blue}1&\color{blue}2&\color{blue}8\\
\color{blue}1&\color{blue}2&\color{blue}8\\
\color{red}1&\color{red}2&\color{red}6\\
\color{red}1&\color{red}2&\color{red}6\\
\color{green}1&\color{green}4&\color{green}8\\
\color{green}1&\color{green}4&\color{green}8
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 1105: \(0\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0.64}\), \(\boldsymbol{-2.32}\), \(\boldsymbol{2.68}\)
Eigenvalues of 1235: \(0\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0.64}\), \(\boldsymbol{-2.32}\), \(\boldsymbol{2.68}\)
CDC
Ryser Switch
\(G_{1235}=\operatorname{ryser}(G_{1105},15, 26)\)
Pair (3392, 3494)
Graph 3392
Graph 3494
\(\begin{pmatrix}
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3392: \(0\), \(0\), \(-1\), \(1\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{17}\right)}\), \(\frac{1}{2} \left(-1-\sqrt{17}\right)\), \(\frac{1}{2} \left(\sqrt{17}-1\right)\)
Eigenvalues of 3494: \(0\), \(0\), \(-1\), \(-1\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{17}\right)}\)
CDC
Ryser Switch
\(G_{3494}=\operatorname{ryser}(G_{3392},57, 68)\)
Pair (3482, 3592)
Graph 3482
Graph 3592
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}11\\
\color{blue}1&\color{blue}2&\color{blue}7\\
\color{red}1&\color{red}3&\color{red}11\\
\color{blue}1&\color{blue}2&\color{blue}7\\
\color{green}1&\color{green}3&\color{green}9\\
\color{green}1&\color{green}3&\color{green}9\\
\color{yellow}1&\color{yellow}4&\color{yellow}11\\
\color{yellow}1&\color{yellow}4&\color{yellow}11
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3482: \(-0.31\), \(-1\), \(1\), \(1.48\), \(-2.17\), \(\boldsymbol{0.14}\), \(\boldsymbol{-2.27}\), \(\boldsymbol{3.13}\)
Eigenvalues of 3592: \(0.31\), \(-1\), \(-1\), \(-1.48\), \(2.17\), \(\boldsymbol{0.14}\), \(\boldsymbol{-2.27}\), \(\boldsymbol{3.13}\)
CDC
Ryser Switch
\(G_{3592}=\operatorname{ryser}(G_{3482},25, 46)\)
Pair (3413, 3779)
Graph 3413
Graph 3779
\(\begin{pmatrix}
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3413: \(0\), \(-1\), \(-1\), \(1\), \(-2\), \(2\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{17}\right)}\)
Eigenvalues of 3779: \(0\), \(1\), \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{17}\right)}\)
CDC
Ryser Switch
\(G_{3779}=\operatorname{ryser}(G_{3413},15, 48)\)
Pair (1270, 5629)
Graph 1270
Graph 5629
\(\begin{pmatrix}
\color{red}1&\color{red}1\\
\color{blue}1&\color{blue}2\\
\color{blue}1&\color{blue}2\\
\color{blue}1&\color{blue}2\\
\color{red}1&\color{red}1\\
\color{blue}1&\color{blue}2\\
\color{blue}1&\color{blue}2\\
\color{blue}1&\color{blue}2
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 1270: \(-1\), \(-1\), \(-1\), \(-2\), \(\boldsymbol{1}\), \(\boldsymbol{1}\), \(\boldsymbol{1}\), \(\boldsymbol{2}\)
Eigenvalues of 5629: \(-1\), \(-1\), \(-1\), \(-1\), \(-1\), \(\boldsymbol{1}\), \(\boldsymbol{2}\), \(\boldsymbol{2}\)
CDC
Ryser Switch
\(G_{5629}=\operatorname{ryser}(G_{1270},26, 48)\)
Pair (5684, 5718)
Graph 5684
Graph 5718
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}11\\
\color{blue}1&\color{blue}2&\color{blue}6\\
\color{blue}1&\color{blue}2&\color{blue}6\\
\color{red}1&\color{red}3&\color{red}11\\
\color{blue}1&\color{blue}2&\color{blue}6\\
\color{blue}1&\color{blue}2&\color{blue}6\\
\color{green}1&\color{green}4&\color{green}10\\
\color{green}1&\color{green}4&\color{green}10
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 5684: \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{1}\), \(\boldsymbol{-2}\), \(\boldsymbol{3}\)
Eigenvalues of 5718: \(-1\), \(-1\), \(\boldsymbol{1}\), \(\boldsymbol{1}\), \(\boldsymbol{1}\), \(\boldsymbol{-2}\), \(\boldsymbol{-2}\), \(\boldsymbol{3}\)
CDC
Ryser Switch
\(G_{5718}=\operatorname{ryser}(G_{5684},25, 36)\)
Pair (3887, 5753)
Graph 3887
Graph 5753
\(\begin{pmatrix}
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{green}1&\color{green}0\\
\color{blue}1&\color{blue}3\\
\color{blue}1&\color{blue}3\\
\color{red}1&\color{red}2\\
\color{yellow}1&\color{yellow}4
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3887: \(-1\), \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{3}\)
Eigenvalues of 5753: \(-1\), \(-1\), \(-1\), \(-2\), \(2\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{3}\)
CDC
Ryser Switch
\(G_{5753}=\operatorname{ryser}(G_{3887},15, 37)\)
Pair (3899, 5755)
Graph 3899
Graph 5755
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{blue}1&\color{blue}0&\color{blue}0\\
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{green}1&\color{green}6&\color{green}18
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3899: \(-1\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{1-\sqrt{7}}\), \(\boldsymbol{1+\sqrt{7}}\)
Eigenvalues of 5755: \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0}\), \(\boldsymbol{1-\sqrt{7}}\), \(\boldsymbol{1+\sqrt{7}}\)
CDC
Ryser Switch
\(G_{5755}=\operatorname{ryser}(G_{3899},15, 37)\)
Pair (3886, 5756)
Graph 3886
Graph 5756
\(\begin{pmatrix}
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}3\\
\color{green}1&\color{green}1\\
\color{blue}1&\color{blue}3\\
\color{red}1&\color{red}2\\
\color{red}1&\color{red}2\\
\color{blue}1&\color{blue}3
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3886: \(-1\), \(1\), \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{1-\sqrt{2}}\), \(\boldsymbol{1+\sqrt{2}}\)
Eigenvalues of 5756: \(-1\), \(-1\), \(-1\), \(1\), \(-2\), \(2\), \(\boldsymbol{1-\sqrt{2}}\), \(\boldsymbol{1+\sqrt{2}}\)
CDC
Ryser Switch
\(G_{5756}=\operatorname{ryser}(G_{3886},15, 37)\)
Pair (3888, 5759)
Graph 3888
Graph 5759
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}6&\color{red}20\\
\color{blue}1&\color{blue}3&\color{blue}10&\color{blue}29\\
\color{blue}1&\color{blue}3&\color{blue}10&\color{blue}29\\
\color{green}1&\color{green}1&\color{green}5&\color{green}13\\
\color{blue}1&\color{blue}3&\color{blue}10&\color{blue}29\\
\color{blue}1&\color{blue}3&\color{blue}10&\color{blue}29\\
\color{red}1&\color{red}2&\color{red}6&\color{red}20\\
\color{yellow}1&\color{yellow}5&\color{yellow}13&\color{yellow}45
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3888: \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{-0.49}\), \(\boldsymbol{0.60}\), \(\boldsymbol{-2.20}\), \(\boldsymbol{3.09}\)
Eigenvalues of 5759: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{-0.49}\), \(\boldsymbol{0.60}\), \(\boldsymbol{-2.20}\), \(\boldsymbol{3.09}\)
CDC
Ryser Switch
\(G_{5759}=\operatorname{ryser}(G_{3888},15, 37)\)
Pair (3903, 5761)
Graph 3903
Graph 5761
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{blue}1&\color{blue}1&\color{blue}7\\
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{green}1&\color{green}7&\color{green}19
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 3903: \(-1\), \(-1\), \(1\), \(1\), \(\boldsymbol{-2}\), \(\boldsymbol{-2}\), \(\boldsymbol{2-\sqrt{3}}\), \(\boldsymbol{2+\sqrt{3}}\)
Eigenvalues of 5761: \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{-2}\), \(\boldsymbol{2-\sqrt{3}}\), \(\boldsymbol{2+\sqrt{3}}\)
CDC
Ryser Switch
\(G_{5761}=\operatorname{ryser}(G_{3903},15, 37)\)
Pair (6471, 7012)
Graph 6471
Graph 7012
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}10&\color{red}32&\color{red}102\\
\color{red}1&\color{red}3&\color{red}10&\color{red}32&\color{red}102\\
\color{blue}1&\color{blue}2&\color{blue}8&\color{blue}22&\color{blue}78\\
\color{green}1&\color{green}2&\color{green}7&\color{green}21&\color{green}71\\
\color{green}1&\color{green}2&\color{green}7&\color{green}21&\color{green}71\\
\color{yellow}1&\color{yellow}4&\color{yellow}11&\color{yellow}39&\color{yellow}117\\
\color{yellow}1&\color{yellow}4&\color{yellow}11&\color{yellow}39&\color{yellow}117\\
\color{orange}1&\color{orange}4&\color{orange}14&\color{orange}42&\color{orange}142
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6471: \(-1\), \(-1\), \(2\), \(\boldsymbol{0}\), \(\boldsymbol{0.55}\), \(\boldsymbol{-1.48}\), \(\boldsymbol{-2.29}\), \(\boldsymbol{3.21}\)
Eigenvalues of 7012: \(1\), \(1\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{0.55}\), \(\boldsymbol{-1.48}\), \(\boldsymbol{-2.29}\), \(\boldsymbol{3.21}\)
CDC
Ryser Switch
\(G_{7012}=\operatorname{ryser}(G_{6471},14, 25)\)
Pair (6479, 7013)
Graph 6479
Graph 7013
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}8\\
\color{red}1&\color{red}3&\color{red}8\\
\color{blue}1&\color{blue}3&\color{blue}9\\
\color{green}1&\color{green}2&\color{green}6\\
\color{green}1&\color{green}2&\color{green}6\\
\color{red}1&\color{red}3&\color{red}8\\
\color{red}1&\color{red}3&\color{red}8\\
\color{blue}1&\color{blue}3&\color{blue}9
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6479: \(-1\), \(-1\), \(-1-\sqrt{2}\), \(2\), \(\boldsymbol{0.53}\), \(\boldsymbol{-1.34}\), \(\boldsymbol{2.81}\), \(\sqrt{2}-1\)
Eigenvalues of 7013: \(1\), \(1\), \(-1-\sqrt{2}\), \(-2\), \(\boldsymbol{0.53}\), \(\boldsymbol{-1.34}\), \(\boldsymbol{2.81}\), \(\sqrt{2}-1\)
CDC
Ryser Switch
\(G_{7013}=\operatorname{ryser}(G_{6479},14, 25)\)
Pair (6481, 7015)
Graph 6481
Graph 7015
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}11&\color{red}37\\
\color{red}1&\color{red}3&\color{red}11&\color{red}37\\
\color{blue}1&\color{blue}3&\color{blue}13&\color{blue}43\\
\color{green}1&\color{green}2&\color{green}7&\color{green}24\\
\color{green}1&\color{green}2&\color{green}7&\color{green}24\\
\color{yellow}1&\color{yellow}4&\color{yellow}13&\color{yellow}48\\
\color{yellow}1&\color{yellow}4&\color{yellow}13&\color{yellow}48\\
\color{orange}1&\color{orange}5&\color{orange}17&\color{orange}61
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6481: \(-1\), \(-1\), \(-2\), \(2\), \(\boldsymbol{-0.28}\), \(\boldsymbol{0.56}\), \(\boldsymbol{-1.79}\), \(\boldsymbol{3.52}\)
Eigenvalues of 7015: \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{-0.28}\), \(\boldsymbol{0.56}\), \(\boldsymbol{-1.79}\), \(\boldsymbol{3.52}\)
CDC
Ryser Switch
\(G_{7015}=\operatorname{ryser}(G_{6481},14, 25)\)
Pair (6476, 7026)
Graph 6476
Graph 7026
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}10\\
\color{red}1&\color{red}3&\color{red}10\\
\color{blue}1&\color{blue}2&\color{blue}6\\
\color{red}1&\color{red}3&\color{red}10\\
\color{red}1&\color{red}3&\color{red}10\\
\color{green}1&\color{green}3&\color{green}8\\
\color{green}1&\color{green}3&\color{green}8\\
\color{yellow}1&\color{yellow}4&\color{yellow}12
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6476: \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{1.15}\), \(\boldsymbol{-2.25}\), \(\boldsymbol{3.10}\)
Eigenvalues of 7026: \(-1\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{1.15}\), \(\boldsymbol{-2.25}\), \(\boldsymbol{3.10}\)
CDC
Ryser Switch
\(G_{7026}=\operatorname{ryser}(G_{6476},14, 25)\)
Pair (6478, 7028)
Graph 6478
Graph 7028
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{blue}1&\color{blue}2&\color{blue}8\\
\color{red}1&\color{red}3&\color{red}13\\
\color{red}1&\color{red}3&\color{red}13\\
\color{green}1&\color{green}4&\color{green}14\\
\color{green}1&\color{green}4&\color{green}14\\
\color{yellow}1&\color{yellow}6&\color{yellow}20
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6478: \(-1\), \(-1\), \(-1\), \(-2\), \(2\), \(\boldsymbol{0.71}\), \(\boldsymbol{-1.49}\), \(\boldsymbol{3.78}\)
Eigenvalues of 7028: \(-1\), \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{0.71}\), \(\boldsymbol{-1.49}\), \(\boldsymbol{3.78}\)
CDC
Ryser Switch
\(G_{7028}=\operatorname{ryser}(G_{6478},14, 25)\)
Pair (6486, 7035)
Graph 6486
Graph 7035
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}11&\color{red}35\\
\color{red}1&\color{red}3&\color{red}11&\color{red}35\\
\color{blue}1&\color{blue}3&\color{blue}11&\color{blue}33\\
\color{red}1&\color{red}3&\color{red}11&\color{red}35\\
\color{red}1&\color{red}3&\color{red}11&\color{red}35\\
\color{green}1&\color{green}3&\color{green}9&\color{green}33\\
\color{green}1&\color{green}3&\color{green}9&\color{green}33\\
\color{yellow}1&\color{yellow}5&\color{yellow}15&\color{yellow}55
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6486: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{-0.34}\), \(\boldsymbol{0.66}\), \(\boldsymbol{-2.68}\), \(\boldsymbol{3.36}\)
Eigenvalues of 7035: \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{-0.34}\), \(\boldsymbol{0.66}\), \(\boldsymbol{-2.68}\), \(\boldsymbol{3.36}\)
CDC
Ryser Switch
\(G_{7035}=\operatorname{ryser}(G_{6486},14, 25)\)
Pair (6488, 7037)
Graph 6488
Graph 7037
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}14&\color{red}53\\
\color{red}1&\color{red}3&\color{red}14&\color{red}53\\
\color{blue}1&\color{blue}3&\color{blue}15&\color{blue}55\\
\color{red}1&\color{red}3&\color{red}14&\color{red}53\\
\color{red}1&\color{red}3&\color{red}14&\color{red}53\\
\color{green}1&\color{green}4&\color{green}16&\color{green}66\\
\color{green}1&\color{green}4&\color{green}16&\color{green}66\\
\color{yellow}1&\color{yellow}7&\color{yellow}23&\color{yellow}103
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 6488: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0.48}\), \(\boldsymbol{-1.53}\), \(\boldsymbol{-2}\), \(\boldsymbol{4.05}\)
Eigenvalues of 7037: \(-1\), \(1\), \(1\), \(\boldsymbol{0.48}\), \(\boldsymbol{-1.53}\), \(\boldsymbol{-2}\), \(\boldsymbol{-2}\), \(\boldsymbol{4.05}\)
CDC
Ryser Switch
\(G_{7037}=\operatorname{ryser}(G_{6488},14, 25)\)
Pair (10840, 10851)
Graph 10840
Graph 10851
\(\begin{pmatrix}
\color{red}1&\color{red}3\\
\color{red}1&\color{red}3\\
\color{blue}1&\color{blue}4\\
\color{blue}1&\color{blue}4\\
\color{red}1&\color{red}3\\
\color{red}1&\color{red}3\\
\color{blue}1&\color{blue}4\\
\color{blue}1&\color{blue}4
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10840: \(1\), \(1\), \(1\), \(-2\), \(-2\), \(-2\), \(\boldsymbol{\frac{1}{2} \left(3-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(3+\sqrt{17}\right)}\)
Eigenvalues of 10851: \(-1\), \(-1\), \(1\), \(-2\), \(-2\), \(2\), \(\boldsymbol{\frac{1}{2} \left(3-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(3+\sqrt{17}\right)}\)
CDC
Ryser Switch
\(G_{10851}=\operatorname{ryser}(G_{10840},14, 36)\)
Pair (5358, 11716)
Note : This is the only pair which requires more than one Ryser switch.
Graph 5358
Graph 11716
\(\begin{pmatrix}
\color{red}1\\
\color{red}1\\
\color{red}1\\
\color{red}1\\
\color{red}1\\
\color{red}1\\
\color{red}1\\
\color{red}1
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 5358: \(-1\), \(-1\), \(-1\), \(1\), \(1\), \(1\), \(-3\), \(\boldsymbol{3}\)
Eigenvalues of 11716: \(-1\), \(-1\), \(-1\), \(-1\), \(-1\), \(-1\), \(\boldsymbol{3}\), \(\boldsymbol{3}\)
CDC
Ryser Switch
\(G_{11716}=\operatorname{ryser}(\operatorname{ryser}(G_{5358},16, 25),38,47)\)
Pair (10867, 11731)
Graph 10867
Graph 11731
\(\begin{pmatrix}
\color{red}1&\color{red}3\\
\color{red}1&\color{red}3\\
\color{blue}1&\color{blue}4\\
\color{blue}1&\color{blue}4\\
\color{red}1&\color{red}3\\
\color{red}1&\color{red}3\\
\color{blue}1&\color{blue}4\\
\color{blue}1&\color{blue}4
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10867: \(0\), \(-1\), \(1\), \(-2\), \(\boldsymbol{\frac{1}{2} \left(3-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(3+\sqrt{17}\right)}\), \(\frac{1}{2} \left(-1-\sqrt{17}\right)\), \(\frac{1}{2} \left(\sqrt{17}-1\right)\)
Eigenvalues of 11731: \(0\), \(-1\), \(-1\), \(-2\), \(\boldsymbol{\frac{1}{2} \left(3-\sqrt{17}\right)}\), \(\boldsymbol{\frac{1}{2} \left(3+\sqrt{17}\right)}\), \(\frac{1}{2} \left(1-\sqrt{17}\right)\), \(\frac{1}{2} \left(1+\sqrt{17}\right)\)
CDC
Ryser Switch
\(G_{11731}=\operatorname{ryser}(G_{10867},15, 26)\)
Pair (10841, 11742)
Graph 10841
Graph 11742
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{red}1&\color{red}3&\color{red}12\\
\color{red}1&\color{red}3&\color{red}12\\
\color{green}1&\color{green}5&\color{green}19\\
\color{green}1&\color{green}5&\color{green}19
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10841: \(1\), \(1\), \(-1-\sqrt{2}\), \(-2\), \(\boldsymbol{-0.32}\), \(\boldsymbol{-1.60}\), \(\boldsymbol{3.92}\), \(\sqrt{2}-1\)
Eigenvalues of 11742: \(-1\), \(-1\), \(-1-\sqrt{2}\), \(2\), \(\boldsymbol{-0.32}\), \(\boldsymbol{-1.60}\), \(\boldsymbol{3.92}\), \(\sqrt{2}-1\)
CDC
Ryser Switch
\(G_{11742}=\operatorname{ryser}(G_{10841},14, 36)\)
Pair (10838, 11747)
Graph 10838
Graph 11747
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}8\\
\color{blue}1&\color{blue}4&\color{blue}14\\
\color{blue}1&\color{blue}4&\color{blue}14\\
\color{blue}1&\color{blue}4&\color{blue}14\\
\color{blue}1&\color{blue}4&\color{blue}14\\
\color{red}1&\color{red}2&\color{red}8\\
\color{green}1&\color{green}4&\color{green}16\\
\color{green}1&\color{green}4&\color{green}16
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10838: \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{41}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{41}\right)}\)
Eigenvalues of 11747: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0}\), \(\boldsymbol{0}\), \(\boldsymbol{\frac{1}{2} \left(1-\sqrt{41}\right)}\), \(\boldsymbol{\frac{1}{2} \left(1+\sqrt{41}\right)}\)
CDC
Ryser Switch
\(G_{11747}=\operatorname{ryser}(G_{10838},14, 36)\)
Pair (10839, 11748)
Graph 10839
Graph 11748
\(\begin{pmatrix}
\color{red}1&\color{red}2&\color{red}8\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{blue}1&\color{blue}4&\color{blue}16\\
\color{red}1&\color{red}2&\color{red}8\\
\color{green}1&\color{green}5&\color{green}21\\
\color{green}1&\color{green}5&\color{green}21
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10839: \(-1\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0.21}\), \(\boldsymbol{-2.30}\), \(\boldsymbol{4.08}\)
Eigenvalues of 11748: \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0.21}\), \(\boldsymbol{-2.30}\), \(\boldsymbol{4.08}\)
CDC
Ryser Switch
\(G_{11748}=\operatorname{ryser}(G_{10839},14, 36)\)
Pair (10849, 11751)
Graph 10849
Graph 11751
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}14&\color{red}56\\
\color{blue}1&\color{blue}4&\color{blue}17&\color{blue}69\\
\color{blue}1&\color{blue}4&\color{blue}17&\color{blue}69\\
\color{blue}1&\color{blue}4&\color{blue}17&\color{blue}69\\
\color{blue}1&\color{blue}4&\color{blue}17&\color{blue}69\\
\color{red}1&\color{red}3&\color{red}14&\color{red}56\\
\color{green}1&\color{green}4&\color{green}16&\color{green}68\\
\color{yellow}1&\color{yellow}6&\color{yellow}22&\color{yellow}96
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10849: \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{0.60}\), \(\boldsymbol{-1.35}\), \(\boldsymbol{-2.39}\), \(\boldsymbol{4.14}\)
Eigenvalues of 11751: \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{0.60}\), \(\boldsymbol{-1.35}\), \(\boldsymbol{-2.39}\), \(\boldsymbol{4.14}\)
CDC
Ryser Switch
\(G_{11751}=\operatorname{ryser}(G_{10849},14, 36)\)
Pair (10850, 11752)
Graph 10850
Graph 11752
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}15\\
\color{blue}1&\color{blue}4&\color{blue}19\\
\color{blue}1&\color{blue}4&\color{blue}19\\
\color{blue}1&\color{blue}4&\color{blue}19\\
\color{blue}1&\color{blue}4&\color{blue}19\\
\color{red}1&\color{red}3&\color{red}15\\
\color{green}1&\color{green}5&\color{green}23\\
\color{yellow}1&\color{yellow}7&\color{yellow}27
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10850: \(-1\), \(1\), \(1\), \(-2\), \(-2\), \(\boldsymbol{0.14}\), \(\boldsymbol{-1.64}\), \(\boldsymbol{4.50}\)
Eigenvalues of 11752: \(-1\), \(-1\), \(-1\), \(-2\), \(2\), \(\boldsymbol{0.14}\), \(\boldsymbol{-1.64}\), \(\boldsymbol{4.50}\)
CDC
Ryser Switch
\(G_{11752}=\operatorname{ryser}(G_{10850},14, 36)\)
Pair (10887, 11755)
Graph 10887
Graph 11755
\(\begin{pmatrix}
\color{red}1&\color{red}3&\color{red}13\\
\color{blue}1&\color{blue}4&\color{blue}17\\
\color{blue}1&\color{blue}4&\color{blue}17\\
\color{blue}1&\color{blue}4&\color{blue}17\\
\color{blue}1&\color{blue}4&\color{blue}17\\
\color{red}1&\color{red}3&\color{red}13\\
\color{green}1&\color{green}5&\color{green}19\\
\color{green}1&\color{green}5&\color{green}19
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10887: \(-0.31\), \(-1\), \(1\), \(1.48\), \(-2.17\), \(\boldsymbol{-0.72}\), \(\boldsymbol{-2.38}\), \(\boldsymbol{4.10}\)
Eigenvalues of 11755: \(0.31\), \(-1\), \(-1\), \(-1.48\), \(2.17\), \(\boldsymbol{-0.72}\), \(\boldsymbol{-2.38}\), \(\boldsymbol{4.10}\)
CDC
Ryser Switch
\(G_{11755}=\operatorname{ryser}(G_{10887},14, 36)\)
Pair (10897, 11761)
Graph 10897
Graph 11761
\(\begin{pmatrix}
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{blue}1&\color{blue}6\\
\color{blue}1&\color{blue}6
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10897: \(0\), \(-1\), \(-1\), \(1\), \(1\), \(-2\), \(\boldsymbol{1-\sqrt{13}}\), \(\boldsymbol{1+\sqrt{13}}\)
Eigenvalues of 11761: \(0\), \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{1-\sqrt{13}}\), \(\boldsymbol{1+\sqrt{13}}\)
CDC
Ryser Switch
\(G_{11761}=\operatorname{ryser}(G_{10897},14, 36)\)
Pair (10898, 11762)
Graph 10898
Graph 11762
\(\begin{pmatrix}
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{red}1&\color{red}4\\
\color{blue}1&\color{blue}7\\
\color{blue}1&\color{blue}7
\end{pmatrix}\)
Walk Matrix
Eigenvalues of 10898: \(-1\), \(-1\), \(-1\), \(1\), \(1\), \(\boldsymbol{-2}\), \(\boldsymbol{-2}\), \(\boldsymbol{5}\)
Eigenvalues of 11762: \(-1\), \(-1\), \(-1\), \(-1\), \(-1\), \(2\), \(\boldsymbol{-2}\), \(\boldsymbol{5}\)
CDC
Ryser Switch
\(G_{11762}=\operatorname{ryser}(G_{10898},14, 36)\)