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Adjacency matrix

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966: 979: 1084: 1061: 3951: 731: 954: 695:. The distance is the length of a shortest path connecting the vertices. Unless lengths of edges are explicitly provided, the length of a path is the number of edges in it. The distance matrix resembles a high power of the adjacency matrix, but instead of telling only whether or not two vertices are connected (i.e., the connection matrix, which contains 2356:
instead be scanned, which takes a larger amount of time, proportional to the number of vertices in the whole graph. On the other hand, testing whether there is an edge between two given vertices can be determined at once with an adjacency matrix, while requiring time proportional to the minimum degree of the two vertices with the adjacency list.
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The convention followed here (for undirected graphs) is that each edge adds 1 to the appropriate cell in the matrix, and each loop (an edge from a vertex to itself) adds 2 to the appropriate cell on the diagonal in the matrix. This allows the degree of a vertex to be easily found by taking the sum of
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and graphs with loops by storing the number of edges between each two vertices in the corresponding matrix element, and by allowing nonzero diagonal elements. Loops may be counted either once (as a single edge) or twice (as two vertex-edge incidences), as long as a consistent convention is followed.
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Besides the space tradeoff, the different data structures also facilitate different operations. Finding all vertices adjacent to a given vertex in an adjacency list is as simple as reading the list, and takes time proportional to the number of neighbors. With an adjacency matrix, an entire row must
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divided by 3 or 6 depending on whether the graph is directed or not. We divide by those values to compensate for the overcounting of each triangle. In an undirected graph, each triangle will be counted twice for all three nodes, because the path can be followed clockwise or counterclockwise :
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of a vertex can be computed by summing the entries of the corresponding column and the out-degree of vertex by summing the entries of the corresponding row. When using the second definition, the in-degree of a vertex is given by the corresponding row sum and the out-degree is given by the
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An alternative form of adjacency matrix (which, however, requires a larger amount of space) replaces the numbers in each element of the matrix with pointers to edge objects (when edges are present) or null pointers (when there is no edge). It is also possible to store
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The former definition is commonly used in graph theory and social network analysis (e.g., sociology, political science, economics, psychology). The latter is more common in other applied sciences (e.g., dynamical systems, physics, network science) where
2320: | / 16 bytes to represent an undirected graph. Although slightly more succinct representations are possible, this method gets close to the information-theoretic lower bound for the minimum number of bits needed to represent all 949:{\displaystyle {\begin{pmatrix}2&1&0&0&1&0\\1&0&1&0&1&0\\0&1&0&1&0&0\\0&0&1&0&1&1\\1&1&0&1&0&0\\0&0&0&1&0&0\end{pmatrix}}} 310: 1865: 1211: 2305:
without incurring the space overhead from storing the many zero entries in the adjacency matrix of the sparse graph. In the following section the adjacency matrix is assumed to be represented by an
1928: 1683: 1601: 1348: 1746: 2067: 2316: | / 8 bytes to represent a directed graph, or (by using a packed triangular format and only storing the lower triangular part of the matrix) approximately | 1559:(it is easy to check that it is an eigenvalue and it is the maximum because of the above bound). The multiplicity of this eigenvalue is the number of connected components of 1628: 1340: 1275: 1240: 1313: 218: 1782: 2488:. Algebraic Coding Theory and Information Theory: DIMACS Workshop, Algebraic Coding Theory and Information Theory. American Mathematical Society. p. 63. 2114:. These can therefore serve as isomorphism invariants of graphs. However, two graphs may possess the same set of eigenvalues but not be isomorphic. Such 1787: 3609: 2838: 2866: 1154: 188:
Undirected graphs often use the latter convention of counting loops twice, whereas directed graphs typically use the former convention.
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The adjacency matrix of a directed graph can be asymmetric. One can define the adjacency matrix of a directed graph either such that
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Because each entry in the adjacency matrix requires only one bit, it can be represented in a very compact way, occupying only |
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in computer programs for manipulating graphs. The main alternative data structure, also in use for this application, is the
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only store non-zero matrix entries and implicitly represent the zero entries. They can, for example, be used to represent
63: 2859: 2454: 2095: 1870: 175:, and zero when there is no edge. The diagonal elements of the matrix are all zero, since edges from a vertex to itself ( 2752: 2293:
The space needed to represent an adjacency matrix and the time needed to perform operations on them is dependent on the
2689: 2609: 2493: 1633: 1528:{\displaystyle \lambda _{1}v_{x}=(Av)_{x}=\sum _{y=1}^{n}A_{x,y}v_{y}\leq \sum _{y=1}^{n}A_{x,y}v_{x}=v_{x}\deg(x).} 67: 2960: 965: 1566: 3987: 3634: 2826:— an educational Java web start game demonstrating the relationship between adjacency matrices and graphs. 3997: 3181: 2852: 1711: 2340:, adjacency lists require less storage space, because they do not waste any space representing edges that are 2742: 978: 3398: 3035: 2707: 2298: 1243: 48: 36: 3473: 2246: 2013: 1083: 2328:, fewer bits per byte can be used to ensure that all bytes are text characters, for instance by using a 3629: 3151: 2887: 2680: 2283: 2452:
Seidel, J. J. (1968). "Strongly Regular Graphs with (−1, 1, 0) Adjacency Matrix Having Eigenvalue 3".
2394:, Cambridge Mathematical Library (2nd ed.), Cambridge University Press, Definition 2.1, p. 7 2230:. A great example of how this is useful is in counting the number of triangles in an undirected graph 1041: 3733: 3604: 3518: 2099: 3838: 3728: 3436: 3116: 2965: 2091: 1111:
contains all ones except along the diagonal where there are only zeros. The adjacency matrix of an
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to replace the nonzero elements with algebraic variables. The same concept can be extended to
3689: 3426: 3276: 3271: 3106: 3081: 3076: 2481: 2333: 2294: 2145: 102: 83: 44: 2841: : Application of the adjacency matrices to the computation generating series of walks. 2552: 3883: 3241: 3071: 3051: 2983: 2728: 2667: 2582: 2438: 2418: 2306: 305:{\displaystyle A={\begin{pmatrix}0_{r,r}&B\\B^{\mathsf {T}}&0_{s,s}\end{pmatrix}},} 40: 93:, a different matrix representation whose elements indicate whether vertex–edge pairs are 8: 3904: 3878: 3456: 3261: 3251: 2778: 2171: 176: 2422: 1295: 3955: 3909: 3899: 3853: 3848: 3777: 3713: 3579: 3316: 3311: 3246: 3236: 3101: 2830:
Open Data Structures - Section 12.1 - AdjacencyMatrix: Representing a Graph by a Matrix
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ijk or ikj. The adjacency matrix can be used to determine whether or not the graph is
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Volume 68 of DIMACS series in discrete mathematics and theoretical computer science
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are taken to be the number of edges between the vertices or the weight of the edge
90: 71: 24: 3554: 3659: 3594: 3574: 3559: 3539: 3523: 3421: 3352: 3342: 3301: 3186: 3156: 2724: 2578: 2434: 2115: 1761: 1694: 1073: 696: 665: 417: 201: 1860:{\displaystyle \lambda (G)=\max _{\left|\lambda _{i}\right|<d}|\lambda _{i}|} 3919: 3863: 3843: 3828: 3787: 3664: 3624: 3589: 3513: 3452: 3431: 3372: 3362: 3347: 3281: 3226: 3216: 3211: 3121: 2999: 2892: 2675: 2623: 2349: 2287: 2279: 2111: 1753: 1108: 1066: 539: 500: 2564: 3981: 3924: 3782: 3723: 3654: 3644: 3639: 3564: 3493: 3367: 3357: 3286: 3206: 3191: 3126: 3004: 2977: 2746: 2594: 719: 98: 32: 3807: 3764: 3669: 3382: 3321: 3231: 3111: 2971: 2598: 2406: 2337: 2332:
representation. Besides avoiding wasted space, this compactness encourages
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so that zero and non-zero entries are all directly represented in storage.
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the values in either its respective row or column in the adjacency matrix.
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is bounded above by the maximum degree. This can be seen as result of the
3649: 3619: 3387: 3221: 3091: 3009: 2119: 2107: 2103: 1144: 1137: 1116: 1112: 971: 375: 79: 2844: 3700: 3161: 1140: 535: 184: 75: 3934: 3508: 2897: 2833: 2814: 2325: 657: 2430: 3868: 179:) are not allowed in simple graphs. It is also sometimes useful in 2705:
Turán, György (1984), "On the succinct representation of graphs",
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The adjacency matrix of a graph should be distinguished from its
2684:(Second ed.), MIT Press and McGraw-Hill, pp. 527–531, 2329: 1603:
for connected graphs. It can be shown that for each eigenvalue
2409:(1962), "The determinant of the adjacency matrix of a graph", 1285:
has maximum absolute value. Without loss of generality assume
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is the adjacency matrix of the directed or undirected graph
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is positive since otherwise you simply take the eigenvector
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Borgatti, Steve; Everett, Martin; Johnson, Jeffrey (2018),
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uniquely represents the graph, and the remaining parts of
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is sometimes used to describe linear dynamics on graphs.
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is the smallest nonnegative integer, such that for some
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of the graph. It is common to denote the eigenvalues by
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As the graph is directed, the matrix is not necessarily
2541:, Chapter 2 ("The spectrum of a graph"), pp. 7–13. 2508: 1132:
The adjacency matrix of an undirected simple graph is
747: 233: 2016: 1873: 1790: 1770: 1714: 1636: 1609: 1569: 1351: 1321: 1298: 1256: 1221: 1157: 741: 221: 2528:(2nd ed.), Oxford University Press, p. 110 2678:(2001), "Section 22.1: Representations of graphs", 1923:{\displaystyle \lambda (G)\geq 2{\sqrt {d-1}}-o(1)} 652:-adjacency matrix. This matrix is used in studying 2559:, Universitext, New York: Springer, pp. 6–7, 2061: 1922: 1859: 1776: 1740: 1677: 1622: 1595: 1527: 1334: 1307: 1269: 1234: 1205: 948: 304: 16:Square matrix used to represent a graph or network 2352:directly in the elements of an adjacency matrix. 2156:) has an interesting interpretation: the element 986:White fields are zeros, colored fields are ones. 3979: 2777: 2643: 2551:Brouwer, Andries E.; Haemers, Willem H. (2012), 1807: 1147:basis. The set of eigenvalues of a graph is the 2550: 1678:{\displaystyle -\lambda _{i}=\lambda _{n+1-i}} 3036: 2860: 2839:Café math : Adjacency Matrices of Graphs 2170:gives the number of (directed or undirected) 1937: 699:), it gives the exact distance between them. 1596:{\displaystyle \lambda _{1}>\lambda _{2}} 74:. The relationship between a graph and the 70:are bidirectional), the adjacency matrix is 62:with zeros on its diagonal. If the graph is 2748:Description of graph6 and sparse6 encodings 3610:Fundamental (linear differential equation) 3043: 3029: 2867: 2853: 1942:Suppose two directed or undirected graphs 2874: 2621: 2479: 1934:, which have applications in many areas. 1741:{\displaystyle \lambda _{1}-\lambda _{2}} 157:is one when there is an edge from vertex 2480:Shum, Kenneth; Blake, Ian (2003-12-18). 2256:adjacency matrix (i.e., if there exists 3915:Matrix representation of conic sections 2658: 2656: 2654: 2652: 191: 101:, which contains information about the 3980: 2624:"Matrices with Permanent Equal to One" 2523: 2451: 2405: 2324:-vertex graphs. For storing graphs in 2278:The adjacency matrix may be used as a 1136:, and therefore has a complete set of 267: 82:of its adjacency matrix is studied in 3024: 2848: 2805: 2773: 2771: 2769: 2704: 2538: 2389: 1760:. It is also useful to introduce the 212:vertices can be written in the form 2649: 707: 2631:Linear Algebra and its Applications 2062:{\displaystyle PA_{1}P^{-1}=A_{2}.} 1246:, but it can be proved easily. Let 378:. In this case, the smaller matrix 136:, the adjacency matrix is a square 113:For a simple graph with vertex set 13: 3050: 2766: 2297:chosen for the underlying matrix. 2273: 2266:is the zero matrix), then it is a 993: 14: 4009: 2798: 2787:Algorithm Design and Applications 2741: 1250:be one eigenvector associated to 1102: 3949: 2513:(2nd ed.), SAGE, p. 20 2125: 1082: 1059: 1040:Using the first definition, the 977: 964: 729: 470:. The biadjacency matrix is the 54:In the special case of a finite 3817:Used in science and engineering 2755:from the original on 2001-04-30 2735: 2698: 2637: 2615: 2222:is the distance between vertex 386:can be discarded as redundant. 3060:Explicitly constrained entries 2644:Goodrich & Tamassia (2015) 2588: 2544: 2532: 2517: 2502: 2473: 2445: 2399: 2383: 2000:if and only if there exists a 1917: 1911: 1883: 1877: 1853: 1838: 1800: 1794: 1519: 1513: 1385: 1375: 681:the distance between vertices 1: 3834:Fundamental (computer vision) 2376: 2299:Sparse matrix representations 1930:. This bound is tight in the 1122: 576: 108: 2974:for cubic Hamiltonian graphs 2721:10.1016/0166-218X(84)90126-4 2708:Discrete Applied Mathematics 2622:Nicholson, Victor A (1975). 2467:10.1016/0024-3795(68)90008-6 2094:and therefore have the same 1867:. This number is bounded by 1623:{\displaystyle \lambda _{i}} 1335:{\displaystyle \lambda _{1}} 1270:{\displaystyle \lambda _{1}} 1235:{\displaystyle \lambda _{1}} 58:, the adjacency matrix is a 7: 3600:Duplication and elimination 3399:eigenvalues or eigenvectors 2482:"Expander graphs and codes" 2359: 1546:is the first eigenvalue of 1127: 702: 35:used to represent a finite 10: 4014: 3533:With specific applications 3162:Discrete Fourier Transform 2888:Graph (abstract data type) 2681:Introduction to Algorithms 2252:If a directed graph has a 1938:Isomorphism and invariants 1705:-regular bipartite graph. 1107:The adjacency matrix of a 1045:corresponding column sum. 1020:it indicates an edge from 43:indicate whether pairs of 3943: 3892: 3824:Cabibbo–Kobayashi–Maskawa 3816: 3762: 3698: 3532: 3451:Satisfying conditions on 3450: 3396: 3335: 3059: 2992: 2953: 2916: 2880: 2565:10.1007/978-1-4614-1939-6 2511:Analyzing Social Networks 2100:characteristic polynomial 1752:and it is related to the 1685:is also an eigenvalue of 2966:Graph Modelling Language 2553:"1.3.6 Bipartite graphs" 2284:representation of graphs 1960:with adjacency matrices 1701:is an eigenvalue of any 1244:Perron–Frobenius theorem 1215:The greatest eigenvalue 390:is sometimes called the 3182:Generalized permutation 2336:. However, for a large 2234:, which is exactly the 1281:the component in which 1009:indicates an edge from 654:strongly regular graphs 644:Seidel adjacency matrix 3988:Algebraic graph theory 3956:Mathematics portal 2602:Algebraic Graph Theory 2392:Algebraic Graph Theory 2390:Biggs, Norman (1993), 2371:Self-similarity matrix 2268:directed acyclic graph 2063: 1924: 1861: 1778: 1742: 1679: 1624: 1597: 1529: 1467: 1417: 1336: 1309: 1271: 1236: 1207: 1089:Coordinates are 0–23. 984:Coordinates are 0–23. 950: 603:of a simple graph has 306: 181:algebraic graph theory 150:such that its element 39:. The elements of the 3998:Graph data structures 2875:Graph representations 2668:Leiserson, Charles E. 2524:Newman, Mark (2018), 2334:locality of reference 2295:matrix representation 2064: 1925: 1862: 1779: 1743: 1680: 1625: 1598: 1530: 1447: 1397: 1337: 1315:, also associated to 1310: 1272: 1237: 1208: 958:Coordinates are 1–6. 951: 642:on the diagonal. The 307: 204:whose two parts have 196:The adjacency matrix 84:spectral graph theory 51:or not in the graph. 2984:Trivial Graph Format 2789:, Wiley, p. 363 2779:Goodrich, Michael T. 2307:array data structure 2014: 1871: 1788: 1768: 1712: 1634: 1607: 1567: 1349: 1319: 1296: 1254: 1219: 1155: 739: 542:, then the elements 219: 192:Of a bipartite graph 3905:Linear independence 3152:Diagonally dominant 2604:, Springer (2001), 2423:1962SIAMR...4..202H 1002:a non-zero element 3910:Matrix exponential 3900:Jordan normal form 3734:Fisher information 3605:Euclidean distance 3519:Totally unimodular 2954:Text-based formats 2810:"Adjacency matrix" 2807:Weisstein, Eric W. 2218:is positive, then 2138:, then the matrix 2096:minimal polynomial 2059: 2002:permutation matrix 1920: 1857: 1836: 1774: 1738: 1675: 1620: 1593: 1525: 1332: 1308:{\displaystyle -v} 1305: 1267: 1232: 1203: 1143:and an orthogonal 946: 940: 638:if it is not, and 599:-adjacency matrix 392:biadjacency matrix 302: 293: 3975: 3974: 3967:Category:Matrices 3839:Fuzzy associative 3729:Doubly stochastic 3437:Positive-definite 3117:Block tridiagonal 3018: 3017: 2917:XML-based formats 2783:Tamassia, Roberto 2672:Rivest, Ronald L. 2664:Cormen, Thomas H. 2574:978-1-4614-1938-9 2557:Spectra of Graphs 1903: 1806: 1777:{\displaystyle A} 1697:. In particular − 1542:-regular graphs, 1100: 1099: 1054:Adjacency matrix 991: 990: 724:Adjacency matrix 708:Undirected graphs 66:(i.e. all of its 4005: 3962:List of matrices 3954: 3953: 3930:Row echelon form 3874:State transition 3803:Seidel adjacency 3685:Totally positive 3545:Alternating sign 3142:Complex Hadamard 3045: 3038: 3031: 3022: 3021: 2993:Related concepts 2908:Incidence matrix 2903:Adjacency matrix 2869: 2862: 2855: 2846: 2845: 2820: 2819: 2792: 2790: 2775: 2764: 2762: 2761: 2760: 2739: 2733: 2731: 2702: 2696: 2694: 2660: 2647: 2641: 2635: 2634: 2628: 2619: 2613: 2592: 2586: 2585: 2548: 2542: 2536: 2530: 2529: 2521: 2515: 2514: 2506: 2500: 2499: 2477: 2471: 2470: 2449: 2443: 2441: 2403: 2397: 2395: 2387: 2366:Laplacian matrix 2323: 2265: 2259: 2243: 2233: 2229: 2225: 2221: 2217: 2211: 2210: 2197: 2193: 2189: 2185: 2181: 2177: 2169: 2168: 2155: 2151: 2143: 2137: 2133: 2116:linear operators 2089: 2080: 2068: 2066: 2065: 2060: 2055: 2054: 2042: 2041: 2029: 2028: 2006: 1995: 1986: 1977: 1968: 1959: 1950: 1932:Ramanujan graphs 1929: 1927: 1926: 1921: 1904: 1893: 1866: 1864: 1863: 1858: 1856: 1851: 1850: 1841: 1835: 1828: 1824: 1823: 1783: 1781: 1780: 1775: 1759: 1747: 1745: 1744: 1739: 1737: 1736: 1724: 1723: 1704: 1700: 1692: 1688: 1684: 1682: 1681: 1676: 1674: 1673: 1649: 1648: 1629: 1627: 1626: 1621: 1619: 1618: 1602: 1600: 1599: 1594: 1592: 1591: 1579: 1578: 1563:, in particular 1562: 1558: 1557: 1549: 1545: 1541: 1534: 1532: 1531: 1526: 1506: 1505: 1493: 1492: 1483: 1482: 1466: 1461: 1443: 1442: 1433: 1432: 1416: 1411: 1393: 1392: 1371: 1370: 1361: 1360: 1341: 1339: 1338: 1333: 1331: 1330: 1314: 1312: 1311: 1306: 1291: 1284: 1280: 1276: 1274: 1273: 1268: 1266: 1265: 1249: 1241: 1239: 1238: 1233: 1231: 1230: 1212: 1210: 1209: 1204: 1199: 1198: 1180: 1179: 1167: 1166: 1086: 1063: 1048: 1047: 1036: 1027: 1023: 1016: 1012: 1008: 981: 968: 955: 953: 952: 947: 945: 944: 733: 716: 715: 694: 687: 680: 669:has in position 651: 650: 641: 637: 633: 621: 602: 598: 597: 573:, respectively. 572: 550: 533: 526: 499: 483: 479: 469: 465: 442: 415: 389: 385: 381: 374: 364: 354: 341: 328: 318: 311: 309: 308: 303: 298: 297: 290: 289: 272: 271: 270: 251: 250: 211: 207: 199: 174: 165: 156: 149: 145: 135: 105:of each vertex. 97:or not, and its 91:incidence matrix 29:adjacency matrix 25:computer science 4013: 4012: 4008: 4007: 4006: 4004: 4003: 4002: 3978: 3977: 3976: 3971: 3948: 3939: 3888: 3812: 3758: 3694: 3528: 3446: 3392: 3331: 3132:Centrosymmetric 3055: 3049: 3019: 3014: 2988: 2949: 2912: 2881:Data structures 2876: 2873: 2801: 2796: 2795: 2776: 2767: 2758: 2756: 2740: 2736: 2703: 2699: 2692: 2676:Stein, Clifford 2661: 2650: 2642: 2638: 2626: 2620: 2616: 2593: 2589: 2575: 2549: 2545: 2537: 2533: 2522: 2518: 2507: 2503: 2496: 2478: 2474: 2455:Lin. Alg. Appl. 2450: 2446: 2431:10.1137/1004057 2404: 2400: 2388: 2384: 2379: 2362: 2321: 2276: 2274:Data structures 2261: 2257: 2239: 2231: 2227: 2223: 2219: 2213: 2200: 2199: 2195: 2191: 2187: 2183: 2179: 2175: 2158: 2157: 2153: 2149: 2139: 2135: 2131: 2128: 2118:are said to be 2088: 2082: 2079: 2073: 2072:In particular, 2050: 2046: 2034: 2030: 2024: 2020: 2015: 2012: 2011: 2004: 1994: 1988: 1985: 1979: 1976: 1970: 1967: 1961: 1958: 1952: 1949: 1943: 1940: 1892: 1872: 1869: 1868: 1852: 1846: 1842: 1837: 1819: 1815: 1811: 1810: 1789: 1786: 1785: 1769: 1766: 1765: 1762:spectral radius 1757: 1732: 1728: 1719: 1715: 1713: 1710: 1709: 1708:The difference 1702: 1698: 1695:bipartite graph 1690: 1686: 1657: 1653: 1644: 1640: 1635: 1632: 1631: 1630:, its opposite 1614: 1610: 1608: 1605: 1604: 1587: 1583: 1574: 1570: 1568: 1565: 1564: 1560: 1552: 1551: 1550:for the vector 1547: 1543: 1539: 1501: 1497: 1488: 1484: 1472: 1468: 1462: 1451: 1438: 1434: 1422: 1418: 1412: 1401: 1388: 1384: 1366: 1362: 1356: 1352: 1350: 1347: 1346: 1326: 1322: 1320: 1317: 1316: 1297: 1294: 1293: 1290: 1286: 1282: 1278: 1261: 1257: 1255: 1252: 1251: 1247: 1226: 1222: 1220: 1217: 1216: 1194: 1190: 1175: 1171: 1162: 1158: 1156: 1153: 1152: 1130: 1125: 1105: 1090: 1088: 1078: 1065: 1034: 1025: 1021: 1014: 1010: 1007: 1003: 996: 994:Directed graphs 985: 983: 970: 957: 939: 938: 933: 928: 923: 918: 913: 907: 906: 901: 896: 891: 886: 881: 875: 874: 869: 864: 859: 854: 849: 843: 842: 837: 832: 827: 822: 817: 811: 810: 805: 800: 795: 790: 785: 779: 778: 773: 768: 763: 758: 753: 743: 742: 740: 737: 736: 710: 705: 693: 689: 686: 682: 670: 666:distance matrix 648: 647: 639: 635: 623: 616: 604: 600: 583: 582: 579: 570: 561: 552: 548: 543: 534:is a bipartite 531: 521: 512: 503: 497: 485: 481: 475: ×  471: 467: 463: 454: 444: 440: 431: 421: 418:bipartite graph 398: 387: 383: 379: 370: ×  366: 360: ×  356: 353: 343: 340: 330: 324: ×  320: 316: 292: 291: 279: 275: 273: 266: 265: 261: 258: 257: 252: 240: 236: 229: 228: 220: 217: 216: 209: 205: 202:bipartite graph 197: 194: 173: 167: 164: 158: 155: 151: 147: 141: ×  137: 133: 124: 114: 111: 17: 12: 11: 5: 4011: 4001: 4000: 3995: 3990: 3973: 3972: 3970: 3969: 3964: 3959: 3944: 3941: 3940: 3938: 3937: 3932: 3927: 3922: 3920:Perfect matrix 3917: 3912: 3907: 3902: 3896: 3894: 3890: 3889: 3887: 3886: 3881: 3876: 3871: 3866: 3861: 3856: 3851: 3846: 3841: 3836: 3831: 3826: 3820: 3818: 3814: 3813: 3811: 3810: 3805: 3800: 3795: 3790: 3785: 3780: 3775: 3769: 3767: 3760: 3759: 3757: 3756: 3751: 3746: 3741: 3736: 3731: 3726: 3721: 3716: 3711: 3705: 3703: 3696: 3695: 3693: 3692: 3690:Transformation 3687: 3682: 3677: 3672: 3667: 3662: 3657: 3652: 3647: 3642: 3637: 3632: 3627: 3622: 3617: 3612: 3607: 3602: 3597: 3592: 3587: 3582: 3577: 3572: 3567: 3562: 3557: 3552: 3547: 3542: 3536: 3534: 3530: 3529: 3527: 3526: 3521: 3516: 3511: 3506: 3501: 3496: 3491: 3486: 3481: 3476: 3467: 3461: 3459: 3448: 3447: 3445: 3444: 3439: 3434: 3429: 3427:Diagonalizable 3424: 3419: 3414: 3409: 3403: 3401: 3397:Conditions on 3394: 3393: 3391: 3390: 3385: 3380: 3375: 3370: 3365: 3360: 3355: 3350: 3345: 3339: 3337: 3333: 3332: 3330: 3329: 3324: 3319: 3314: 3309: 3304: 3299: 3294: 3289: 3284: 3279: 3277:Skew-symmetric 3274: 3272:Skew-Hermitian 3269: 3264: 3259: 3254: 3249: 3244: 3239: 3234: 3229: 3224: 3219: 3214: 3209: 3204: 3199: 3194: 3189: 3184: 3179: 3174: 3169: 3164: 3159: 3154: 3149: 3144: 3139: 3134: 3129: 3124: 3119: 3114: 3109: 3107:Block-diagonal 3104: 3099: 3094: 3089: 3084: 3082:Anti-symmetric 3079: 3077:Anti-Hermitian 3074: 3069: 3063: 3061: 3057: 3056: 3048: 3047: 3040: 3033: 3025: 3016: 3015: 3013: 3012: 3007: 3002: 3000:Graph database 2996: 2994: 2990: 2989: 2987: 2986: 2981: 2975: 2969: 2963: 2957: 2955: 2951: 2950: 2948: 2947: 2942: 2937: 2932: 2929: 2926: 2920: 2918: 2914: 2913: 2911: 2910: 2905: 2900: 2895: 2893:Adjacency list 2890: 2884: 2882: 2878: 2877: 2872: 2871: 2864: 2857: 2849: 2843: 2842: 2836: 2827: 2821: 2800: 2799:External links 2797: 2794: 2793: 2765: 2743:McKay, Brendan 2734: 2715:(3): 289–294, 2697: 2690: 2648: 2636: 2614: 2587: 2573: 2543: 2531: 2516: 2501: 2494: 2472: 2461:(2): 281–298. 2444: 2417:(3): 202–210, 2398: 2381: 2380: 2378: 2375: 2374: 2373: 2368: 2361: 2358: 2288:adjacency list 2280:data structure 2275: 2272: 2198:, the element 2146:matrix product 2127: 2124: 2086: 2077: 2070: 2069: 2058: 2053: 2049: 2045: 2040: 2037: 2033: 2027: 2023: 2019: 1992: 1983: 1974: 1965: 1956: 1947: 1939: 1936: 1919: 1916: 1913: 1910: 1907: 1902: 1899: 1896: 1891: 1888: 1885: 1882: 1879: 1876: 1855: 1849: 1845: 1840: 1834: 1831: 1827: 1822: 1818: 1814: 1809: 1805: 1802: 1799: 1796: 1793: 1773: 1748:is called the 1735: 1731: 1727: 1722: 1718: 1672: 1669: 1666: 1663: 1660: 1656: 1652: 1647: 1643: 1639: 1617: 1613: 1590: 1586: 1582: 1577: 1573: 1536: 1535: 1524: 1521: 1518: 1515: 1512: 1509: 1504: 1500: 1496: 1491: 1487: 1481: 1478: 1475: 1471: 1465: 1460: 1457: 1454: 1450: 1446: 1441: 1437: 1431: 1428: 1425: 1421: 1415: 1410: 1407: 1404: 1400: 1396: 1391: 1387: 1383: 1380: 1377: 1374: 1369: 1365: 1359: 1355: 1329: 1325: 1304: 1301: 1288: 1264: 1260: 1229: 1225: 1202: 1197: 1193: 1189: 1186: 1183: 1178: 1174: 1170: 1165: 1161: 1129: 1126: 1124: 1121: 1109:complete graph 1104: 1103:Trivial graphs 1101: 1098: 1097: 1080: 1076: 1056: 1055: 1052: 1051:Labeled graph 1030: 1029: 1018: 1005: 995: 992: 989: 988: 975: 961: 960: 943: 937: 934: 932: 929: 927: 924: 922: 919: 917: 914: 912: 909: 908: 905: 902: 900: 897: 895: 892: 890: 887: 885: 882: 880: 877: 876: 873: 870: 868: 865: 863: 860: 858: 855: 853: 850: 848: 845: 844: 841: 838: 836: 833: 831: 828: 826: 823: 821: 818: 816: 813: 812: 809: 806: 804: 801: 799: 796: 794: 791: 789: 786: 784: 781: 780: 777: 774: 772: 769: 767: 764: 762: 759: 757: 754: 752: 749: 748: 746: 734: 726: 725: 722: 709: 706: 704: 701: 697:Boolean values 691: 684: 608: 578: 575: 566: 557: 546: 540:weighted graph 517: 508: 501:if and only if 489: 459: 452: 436: 429: 397:Formally, let 355:represent the 345: 332: 313: 312: 301: 296: 288: 285: 282: 278: 274: 269: 264: 260: 259: 256: 253: 249: 246: 243: 239: 235: 234: 232: 227: 224: 193: 190: 171: 162: 153: 129: 122: 110: 107: 15: 9: 6: 4: 3: 2: 4010: 3999: 3996: 3994: 3991: 3989: 3986: 3985: 3983: 3968: 3965: 3963: 3960: 3958: 3957: 3952: 3946: 3945: 3942: 3936: 3933: 3931: 3928: 3926: 3925:Pseudoinverse 3923: 3921: 3918: 3916: 3913: 3911: 3908: 3906: 3903: 3901: 3898: 3897: 3895: 3893:Related terms 3891: 3885: 3884:Z (chemistry) 3882: 3880: 3877: 3875: 3872: 3870: 3867: 3865: 3862: 3860: 3857: 3855: 3852: 3850: 3847: 3845: 3842: 3840: 3837: 3835: 3832: 3830: 3827: 3825: 3822: 3821: 3819: 3815: 3809: 3806: 3804: 3801: 3799: 3796: 3794: 3791: 3789: 3786: 3784: 3781: 3779: 3776: 3774: 3771: 3770: 3768: 3766: 3761: 3755: 3752: 3750: 3747: 3745: 3742: 3740: 3737: 3735: 3732: 3730: 3727: 3725: 3722: 3720: 3717: 3715: 3712: 3710: 3707: 3706: 3704: 3702: 3697: 3691: 3688: 3686: 3683: 3681: 3678: 3676: 3673: 3671: 3668: 3666: 3663: 3661: 3658: 3656: 3653: 3651: 3648: 3646: 3643: 3641: 3638: 3636: 3633: 3631: 3628: 3626: 3623: 3621: 3618: 3616: 3613: 3611: 3608: 3606: 3603: 3601: 3598: 3596: 3593: 3591: 3588: 3586: 3583: 3581: 3578: 3576: 3573: 3571: 3568: 3566: 3563: 3561: 3558: 3556: 3553: 3551: 3548: 3546: 3543: 3541: 3538: 3537: 3535: 3531: 3525: 3522: 3520: 3517: 3515: 3512: 3510: 3507: 3505: 3502: 3500: 3497: 3495: 3492: 3490: 3487: 3485: 3482: 3480: 3477: 3475: 3471: 3468: 3466: 3463: 3462: 3460: 3458: 3454: 3449: 3443: 3440: 3438: 3435: 3433: 3430: 3428: 3425: 3423: 3420: 3418: 3415: 3413: 3410: 3408: 3405: 3404: 3402: 3400: 3395: 3389: 3386: 3384: 3381: 3379: 3376: 3374: 3371: 3369: 3366: 3364: 3361: 3359: 3356: 3354: 3351: 3349: 3346: 3344: 3341: 3340: 3338: 3334: 3328: 3325: 3323: 3320: 3318: 3315: 3313: 3310: 3308: 3305: 3303: 3300: 3298: 3295: 3293: 3290: 3288: 3285: 3283: 3280: 3278: 3275: 3273: 3270: 3268: 3265: 3263: 3260: 3258: 3255: 3253: 3250: 3248: 3245: 3243: 3242:Pentadiagonal 3240: 3238: 3235: 3233: 3230: 3228: 3225: 3223: 3220: 3218: 3215: 3213: 3210: 3208: 3205: 3203: 3200: 3198: 3195: 3193: 3190: 3188: 3185: 3183: 3180: 3178: 3175: 3173: 3170: 3168: 3165: 3163: 3160: 3158: 3155: 3153: 3150: 3148: 3145: 3143: 3140: 3138: 3135: 3133: 3130: 3128: 3125: 3123: 3120: 3118: 3115: 3113: 3110: 3108: 3105: 3103: 3100: 3098: 3095: 3093: 3090: 3088: 3085: 3083: 3080: 3078: 3075: 3073: 3072:Anti-diagonal 3070: 3068: 3065: 3064: 3062: 3058: 3053: 3046: 3041: 3039: 3034: 3032: 3027: 3026: 3023: 3011: 3008: 3006: 3005:Graph drawing 3003: 3001: 2998: 2997: 2995: 2991: 2985: 2982: 2979: 2978:Newick format 2976: 2973: 2970: 2967: 2964: 2962: 2959: 2958: 2956: 2952: 2946: 2943: 2941: 2938: 2936: 2933: 2930: 2927: 2925: 2922: 2921: 2919: 2915: 2909: 2906: 2904: 2901: 2899: 2896: 2894: 2891: 2889: 2886: 2885: 2883: 2879: 2870: 2865: 2863: 2858: 2856: 2851: 2850: 2847: 2840: 2837: 2835: 2831: 2828: 2825: 2822: 2817: 2816: 2811: 2808: 2803: 2802: 2788: 2784: 2780: 2774: 2772: 2770: 2754: 2750: 2749: 2744: 2738: 2730: 2726: 2722: 2718: 2714: 2710: 2709: 2701: 2693: 2691:0-262-03293-7 2687: 2683: 2682: 2677: 2673: 2669: 2665: 2659: 2657: 2655: 2653: 2645: 2640: 2632: 2625: 2618: 2611: 2610:0-387-95241-1 2607: 2603: 2600: 2599:Royle, Gordon 2596: 2595:Godsil, Chris 2591: 2584: 2580: 2576: 2570: 2566: 2562: 2558: 2554: 2547: 2540: 2535: 2527: 2520: 2512: 2505: 2497: 2495:9780821871102 2491: 2487: 2483: 2476: 2468: 2464: 2460: 2457: 2456: 2448: 2440: 2436: 2432: 2428: 2424: 2420: 2416: 2412: 2408: 2407:Harary, Frank 2402: 2393: 2386: 2382: 2372: 2369: 2367: 2364: 2363: 2357: 2353: 2351: 2345: 2343: 2339: 2335: 2331: 2327: 2319: 2315: 2310: 2308: 2304: 2303:sparse graphs 2300: 2296: 2291: 2289: 2285: 2281: 2271: 2269: 2264: 2255: 2250: 2248: 2242: 2237: 2216: 2208: 2204: 2173: 2166: 2162: 2147: 2142: 2126:Matrix powers 2123: 2121: 2117: 2113: 2109: 2105: 2101: 2097: 2093: 2085: 2076: 2056: 2051: 2047: 2043: 2038: 2035: 2031: 2025: 2021: 2017: 2010: 2009: 2008: 2003: 1999: 1991: 1982: 1973: 1964: 1955: 1946: 1935: 1933: 1914: 1908: 1905: 1900: 1897: 1894: 1889: 1886: 1880: 1874: 1847: 1843: 1832: 1829: 1825: 1820: 1816: 1812: 1803: 1797: 1791: 1771: 1763: 1755: 1751: 1733: 1729: 1725: 1720: 1716: 1706: 1696: 1670: 1667: 1664: 1661: 1658: 1654: 1650: 1645: 1641: 1637: 1615: 1611: 1588: 1584: 1580: 1575: 1571: 1555: 1522: 1516: 1510: 1507: 1502: 1498: 1494: 1489: 1485: 1479: 1476: 1473: 1469: 1463: 1458: 1455: 1452: 1448: 1444: 1439: 1435: 1429: 1426: 1423: 1419: 1413: 1408: 1405: 1402: 1398: 1394: 1389: 1381: 1378: 1372: 1367: 1363: 1357: 1353: 1345: 1344: 1343: 1327: 1323: 1302: 1299: 1262: 1258: 1245: 1227: 1223: 1213: 1200: 1195: 1191: 1187: 1184: 1181: 1176: 1172: 1168: 1163: 1159: 1150: 1146: 1142: 1139: 1135: 1120: 1118: 1114: 1110: 1096: 1094: 1085: 1081: 1079: 1075: 1071: 1068: 1062: 1058: 1057: 1053: 1050: 1049: 1046: 1043: 1038: 1019: 1001: 1000: 999: 987: 980: 976: 974: 973: 967: 963: 962: 959: 941: 935: 930: 925: 920: 915: 910: 903: 898: 893: 888: 883: 878: 871: 866: 861: 856: 851: 846: 839: 834: 829: 824: 819: 814: 807: 802: 797: 792: 787: 782: 775: 770: 765: 760: 755: 750: 744: 735: 732: 728: 727: 723: 721: 720:Labeled graph 718: 717: 714: 700: 698: 678: 674: 668: 667: 661: 659: 655: 645: 631: 627: 620: 615: 611: 607: 595: 591: 587: 574: 569: 565: 560: 556: 549: 541: 537: 528: 525: 520: 516: 511: 507: 502: 496: 492: 488: 478: 474: 462: 458: 451: 447: 439: 435: 428: 424: 419: 413: 409: 405: 401: 395: 393: 377: 376:zero matrices 373: 369: 363: 359: 352: 348: 339: 335: 327: 323: 299: 294: 286: 283: 280: 276: 262: 254: 247: 244: 241: 237: 230: 225: 222: 215: 214: 213: 203: 189: 186: 182: 178: 170: 161: 144: 140: 132: 128: 121: 117: 106: 104: 100: 99:degree matrix 96: 92: 87: 85: 81: 77: 73: 69: 65: 61: 57: 52: 50: 46: 42: 38: 34: 33:square matrix 30: 26: 22: 3947: 3879:Substitution 3772: 3765:graph theory 3262:Quaternionic 3252:Persymmetric 2972:LCF notation 2902: 2813: 2786: 2757:, retrieved 2747: 2737: 2712: 2706: 2700: 2679: 2639: 2630: 2617: 2601: 2590: 2556: 2546: 2539:Biggs (1993) 2534: 2525: 2519: 2510: 2504: 2485: 2475: 2458: 2453: 2447: 2414: 2410: 2401: 2391: 2385: 2354: 2350:edge weights 2346: 2341: 2338:sparse graph 2317: 2313: 2311: 2292: 2277: 2262: 2251: 2240: 2214: 2206: 2202: 2178:from vertex 2164: 2160: 2140: 2129: 2083: 2074: 2071: 1989: 1980: 1971: 1962: 1953: 1944: 1941: 1750:spectral gap 1707: 1553: 1537: 1214: 1148: 1131: 1106: 1087: 1070:Cayley graph 1064: 1039: 1031: 997: 982: 969: 956: 711: 676: 672: 664: 662: 634:is an edge, 629: 625: 618: 613: 609: 605: 593: 589: 585: 580: 567: 563: 558: 554: 545: 529: 523: 518: 514: 509: 505: 494: 490: 486: 476: 472: 460: 456: 449: 445: 437: 433: 426: 422: 411: 407: 403: 399: 396: 391: 371: 367: 361: 357: 350: 346: 337: 333: 329:matrix, and 325: 321: 314: 195: 168: 159: 142: 138: 130: 126: 119: 115: 112: 88: 80:eigenvectors 60:(0,1)-matrix 56:simple graph 53: 28: 21:graph theory 18: 3854:Hamiltonian 3778:Biadjacency 3714:Correlation 3630:Householder 3580:Commutation 3317:Vandermonde 3312:Tridiagonal 3247:Permutation 3237:Nonnegative 3222:Matrix unit 3102:Bisymmetric 3010:Linked data 2824:Fluffschack 2411:SIAM Review 2226:and vertex 2144:(i.e., the 2120:isospectral 2108:determinant 2104:eigenvalues 1978:are given. 1784:denoted by 1556:= (1, …, 1) 1145:eigenvector 1141:eigenvalues 1117:zero matrix 1113:empty graph 972:Nauru graph 480:0–1 matrix 420:with parts 185:multigraphs 76:eigenvalues 3982:Categories 3754:Transition 3749:Stochastic 3719:Covariance 3701:statistics 3680:Symplectic 3675:Similarity 3504:Unimodular 3499:Orthogonal 3484:Involutory 3479:Invertible 3474:Projection 3470:Idempotent 3412:Convergent 3307:Triangular 3257:Polynomial 3202:Hessenberg 3172:Equivalent 3167:Elementary 3147:Copositive 3137:Conference 3097:Bidiagonal 2759:2012-02-10 2633:(12): 187. 2377:References 2326:text files 2260:such that 2182:to vertex 2174:of length 2152:copies of 2007:such that 1998:isomorphic 1123:Properties 1042:in-degrees 658:two-graphs 649:(−1, 1, 0) 577:Variations 536:multigraph 466:and edges 166:to vertex 109:Definition 64:undirected 3935:Wronskian 3859:Irregular 3849:Gell-Mann 3798:Laplacian 3793:Incidence 3773:Adjacency 3744:Precision 3709:Centering 3615:Generator 3585:Confusion 3570:Circulant 3550:Augmented 3509:Unipotent 3489:Nilpotent 3465:Congruent 3442:Stieltjes 3417:Defective 3407:Companion 3378:Redheffer 3297:Symmetric 3292:Sylvester 3267:Signature 3197:Hermitian 3177:Frobenius 3087:Arrowhead 3067:Alternant 2980:for trees 2898:Edge list 2834:Pat Morin 2815:MathWorld 2344:present. 2254:nilpotent 2247:connected 2036:− 1906:− 1898:− 1887:≥ 1875:λ 1844:λ 1817:λ 1792:λ 1754:expansion 1730:λ 1726:− 1717:λ 1668:− 1655:λ 1642:λ 1638:− 1612:λ 1585:λ 1572:λ 1511:⁡ 1449:∑ 1445:≤ 1399:∑ 1354:λ 1324:λ 1300:− 1259:λ 1224:λ 1192:λ 1188:≥ 1185:⋯ 1182:≥ 1173:λ 1169:≥ 1160:λ 1134:symmetric 1093:symmetric 484:in which 72:symmetric 3993:Matrices 3763:Used in 3699:Used in 3660:Rotation 3635:Jacobian 3595:Distance 3575:Cofactor 3560:Carleman 3540:Adjugate 3524:Weighing 3457:inverses 3453:products 3422:Definite 3353:Identity 3343:Exchange 3336:Constant 3302:Toeplitz 3187:Hadamard 3157:Diagonal 2785:(2015), 2753:archived 2526:Networks 2360:See also 2282:for the 1149:spectrum 1128:Spectrum 1067:Directed 703:Examples 95:incident 49:adjacent 45:vertices 3864:Overlap 3829:Density 3788:Edmonds 3665:Seifert 3625:Hessian 3590:Coxeter 3514:Unitary 3432:Hurwitz 3363:Of ones 3348:Hilbert 3282:Skyline 3227:Metzler 3217:Logical 3212:Integer 3122:Boolean 3054:classes 2935:GraphML 2729:0749658 2612:, p.164 2583:2882891 2439:0144330 2419:Bibcode 2092:similar 1342:. Then 455:, ..., 432:, ..., 146:matrix 3783:Degree 3724:Design 3655:Random 3645:Payoff 3640:Moment 3565:Cartan 3555:Bézout 3494:Normal 3368:Pascal 3358:Lehmer 3287:Sparse 3207:Hollow 3192:Hankel 3127:Cauchy 3052:Matrix 2727:  2688:  2608:  2581:  2571:  2492:  2437:  2330:Base64 319:is an 315:where 103:degree 41:matrix 3844:Gamma 3808:Tutte 3670:Shear 3383:Shift 3373:Pauli 3322:Walsh 3232:Moore 3112:Block 2968:(GML) 2945:XGMML 2928:DotML 2627:(PDF) 2236:trace 2186:. If 2172:walks 2112:trace 1693:is a 1115:is a 646:is a 416:be a 200:of a 177:loops 125:, …, 68:edges 37:graph 31:is a 27:, an 3650:Pick 3620:Gram 3388:Zero 3092:Band 2931:GEXF 2924:DGML 2686:ISBN 2606:ISBN 2569:ISBN 2490:ISBN 2110:and 2090:are 2081:and 1996:are 1987:and 1969:and 1951:and 1830:< 1581:> 1538:For 1277:and 1138:real 688:and 663:The 656:and 522:) ∈ 365:and 342:and 208:and 78:and 47:are 23:and 3739:Hat 3472:or 3455:or 2961:DOT 2940:GXL 2717:doi 2561:doi 2463:doi 2427:doi 2342:not 2238:of 2212:of 2148:of 2130:If 1808:max 1764:of 1756:of 1689:if 1508:deg 1072:of 1024:to 1013:to 622:if 581:An 547:i,j 538:or 530:If 498:= 1 448:= { 425:= { 402:= ( 118:= { 19:In 3984:: 2832:, 2812:. 2781:; 2768:^ 2751:, 2745:, 2725:MR 2723:, 2711:, 2674:; 2670:; 2666:; 2651:^ 2629:. 2597:; 2579:MR 2577:, 2567:, 2555:, 2484:. 2435:MR 2433:, 2425:, 2413:, 2290:. 2270:. 2249:. 2205:, 2194:, 2163:, 2122:. 2106:, 2102:, 2098:, 1119:. 1095:. 1017:or 1006:ij 675:, 660:. 628:, 617:= 592:, 588:, 562:, 527:. 513:, 443:, 410:, 406:, 394:. 154:ij 86:. 3869:S 3327:Z 3044:e 3037:t 3030:v 2868:e 2861:t 2854:v 2818:. 2791:. 2763:. 2732:. 2719:: 2713:8 2695:. 2563:: 2498:. 2469:. 2465:: 2459:1 2442:. 2429:: 2421:: 2415:4 2396:. 2322:n 2318:V 2314:V 2263:A 2258:n 2241:A 2232:G 2228:j 2224:i 2220:n 2215:A 2209:) 2207:j 2203:i 2201:( 2196:j 2192:i 2188:n 2184:j 2180:i 2176:n 2167:) 2165:j 2161:i 2159:( 2154:A 2150:n 2141:A 2136:G 2132:A 2087:2 2084:A 2078:1 2075:A 2057:. 2052:2 2048:A 2044:= 2039:1 2032:P 2026:1 2022:A 2018:P 2005:P 1993:2 1990:G 1984:1 1981:G 1975:2 1972:A 1966:1 1963:A 1957:2 1954:G 1948:1 1945:G 1918:) 1915:1 1912:( 1909:o 1901:1 1895:d 1890:2 1884:) 1881:G 1878:( 1854:| 1848:i 1839:| 1833:d 1826:| 1821:i 1813:| 1804:= 1801:) 1798:G 1795:( 1772:A 1758:G 1734:2 1721:1 1703:d 1699:d 1691:G 1687:A 1671:i 1665:1 1662:+ 1659:n 1651:= 1646:i 1616:i 1589:2 1576:1 1561:G 1554:v 1548:A 1544:d 1540:d 1523:. 1520:) 1517:x 1514:( 1503:x 1499:v 1495:= 1490:x 1486:v 1480:y 1477:, 1474:x 1470:A 1464:n 1459:1 1456:= 1453:y 1440:y 1436:v 1430:y 1427:, 1424:x 1420:A 1414:n 1409:1 1406:= 1403:y 1395:= 1390:x 1386:) 1382:v 1379:A 1376:( 1373:= 1368:x 1364:v 1358:1 1328:1 1303:v 1289:x 1287:v 1283:v 1279:x 1263:1 1248:v 1228:1 1201:. 1196:n 1177:2 1164:1 1077:4 1074:S 1035:A 1028:. 1026:i 1022:j 1015:j 1011:i 1004:A 942:) 936:0 931:0 926:1 921:0 916:0 911:0 904:0 899:0 894:1 889:0 884:1 879:1 872:1 867:1 862:0 857:1 852:0 847:0 840:0 835:0 830:1 825:0 820:1 815:0 808:0 803:1 798:0 793:1 788:0 783:1 776:0 771:1 766:0 761:0 756:1 751:2 745:( 692:j 690:v 685:i 683:v 679:) 677:j 673:i 671:( 640:c 636:b 632:) 630:j 626:i 624:( 619:a 614:j 612:, 610:i 606:A 601:A 596:) 594:c 590:b 586:a 584:( 571:) 568:j 564:v 559:i 555:u 553:( 544:b 532:G 524:E 519:j 515:v 510:i 506:u 504:( 495:j 493:, 491:i 487:b 482:B 477:s 473:r 468:E 464:} 461:s 457:v 453:1 450:v 446:V 441:} 438:r 434:u 430:1 427:u 423:U 414:) 412:E 408:V 404:U 400:G 388:B 384:A 380:B 372:s 368:s 362:r 358:r 351:s 349:, 347:s 344:0 338:r 336:, 334:r 331:0 326:s 322:r 317:B 300:, 295:) 287:s 284:, 281:s 277:0 268:T 263:B 255:B 248:r 245:, 242:r 238:0 231:( 226:= 223:A 210:s 206:r 198:A 172:j 169:u 163:i 160:u 152:A 148:A 143:n 139:n 134:} 131:n 127:u 123:1 120:u 116:U

Index

graph theory
computer science
square matrix
graph
matrix
vertices
adjacent
simple graph
(0,1)-matrix
undirected
edges
symmetric
eigenvalues
eigenvectors
spectral graph theory
incidence matrix
incident
degree matrix
degree
loops
algebraic graph theory
multigraphs
bipartite graph
zero matrices
bipartite graph
if and only if
multigraph
weighted graph
Seidel adjacency matrix
strongly regular graphs

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