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Edge and vertex spaces

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of the vertex space is thus the number of vertices of the graph, while the dimension of the edge space is the number of edges.
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These definitions can be made more explicit. For example, we can describe the edge space as follows:
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made into a vector space with similar vector addition and scalar multiplication as defined for
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sets, respectively. These vector spaces make it possible to use techniques of
1127: 150: 48: 32: 28: 1113: 1061: 1118: 1065: 461: 1083: 1103:(the electronic 3rd edition is freely available on author's site). 599:{\displaystyle 0\cdot P:=\emptyset \qquad P\in {\mathcal {E}}(G)} 537:{\displaystyle P+Q:=P\triangle Q\qquad P,Q\in {\mathcal {E}}(G)} 199:{\displaystyle \mathbb {Z} /2\mathbb {Z} :=\lbrace 0,1\rbrace } 284:
which assigns a 1 to its vertices. Also every subset of
943:, as a linear transformation, maps each edge to its two 893:{\displaystyle H:{\mathcal {E}}(G)\to {\mathcal {V}}(G)} 655:{\displaystyle 1\cdot P:=P\qquad P\in {\mathcal {E}}(G)} 240:{\displaystyle V\rightarrow \mathbb {Z} /2\mathbb {Z} } 1019: 996: 976: 953: 929: 909: 848: 822: 802: 758: 721: 685: 613: 557: 483: 433: 413: 363: 330: 294: 253: 212: 159: 118: 77: 1049: 1002: 982: 962: 935: 915: 892: 828: 808: 777: 740: 704: 654: 598: 536: 452: 419: 384: 349: 313: 272: 239: 198: 137: 101: 1125: 903:between the edge space and the vertex space of 392:-vector space freely generated by the edge set 193: 181: 385:{\displaystyle \mathbb {Z} /2\mathbb {Z} } 378: 365: 233: 220: 174: 161: 1081: 14: 1126: 321:by its characteristic function. The 280:naturally corresponds the subset of 24: 876: 857: 761: 724: 688: 638: 582: 570: 520: 499: 436: 333: 297: 256: 121: 109:be a finite undirected graph. The 25: 1145: 778:{\displaystyle {\mathcal {E}}(G)} 741:{\displaystyle {\mathcal {V}}(G)} 705:{\displaystyle {\mathcal {E}}(G)} 453:{\displaystyle {\mathcal {E}}(G)} 350:{\displaystyle {\mathcal {E}}(G)} 314:{\displaystyle {\mathcal {V}}(G)} 273:{\displaystyle {\mathcal {V}}(G)} 138:{\displaystyle {\mathcal {V}}(G)} 629: 573: 505: 1032: 1023: 887: 881: 871: 868: 862: 772: 766: 735: 729: 699: 693: 649: 643: 593: 587: 531: 525: 447: 441: 344: 338: 308: 302: 267: 261: 216: 132: 126: 96: 84: 13: 1: 1075: 788: 149:is the vector space over the 66: 7: 1107: 288:is uniquely represented in 10: 1150: 1082:Diestel, Reinhard (2005), 923:. The incidence matrix of 1050:{\displaystyle H(vu)=v+u} 407:elements are subsets of 102:{\displaystyle G:=(V,E)} 51:defined in terms of the 63:in studying the graph. 1134:Algebraic graph theory 1051: 1004: 984: 964: 937: 917: 894: 830: 810: 779: 742: 715:One can also think of 706: 656: 600: 538: 454: 421: 386: 351: 315: 274: 241: 200: 139: 103: 1052: 1005: 985: 965: 938: 918: 895: 838:linear transformation 836:defines one possible 831: 811: 780: 743: 707: 657: 601: 547:scalar multiplication 539: 455: 422: 387: 352: 316: 275: 242: 201: 140: 104: 1017: 994: 974: 970:be the edge between 951: 927: 907: 846: 820: 800: 756: 748:as the power set of 719: 683: 611: 555: 481: 475:symmetric difference 431: 427:, that is, as a set 411: 361: 328: 292: 251: 247:. Every element of 210: 157: 116: 75: 1072:of the edge space. 1047: 1000: 980: 963:{\displaystyle vu} 960: 933: 913: 890: 826: 806: 775: 738: 702: 652: 596: 534: 473:is defined as the 450: 417: 382: 347: 311: 270: 237: 196: 135: 99: 1003:{\displaystyle u} 983:{\displaystyle v} 936:{\displaystyle G} 916:{\displaystyle G} 829:{\displaystyle G} 809:{\displaystyle H} 420:{\displaystyle E} 206:of all functions 153:of two elements 16:(Redirected from 1141: 1102: 1088:(3rd ed.), 1056: 1054: 1053: 1048: 1009: 1007: 1006: 1001: 989: 987: 986: 981: 969: 967: 966: 961: 942: 940: 939: 934: 922: 920: 919: 914: 899: 897: 896: 891: 880: 879: 861: 860: 835: 833: 832: 827: 815: 813: 812: 807: 795:incidence matrix 784: 782: 781: 776: 765: 764: 747: 745: 744: 739: 728: 727: 711: 709: 708: 703: 692: 691: 661: 659: 658: 653: 642: 641: 605: 603: 602: 597: 586: 585: 543: 541: 540: 535: 524: 523: 459: 457: 456: 451: 440: 439: 426: 424: 423: 418: 391: 389: 388: 383: 381: 373: 368: 356: 354: 353: 348: 337: 336: 320: 318: 317: 312: 301: 300: 279: 277: 276: 271: 260: 259: 246: 244: 243: 238: 236: 228: 223: 205: 203: 202: 197: 177: 169: 164: 144: 142: 141: 136: 125: 124: 108: 106: 105: 100: 45:undirected graph 21: 1149: 1148: 1144: 1143: 1142: 1140: 1139: 1138: 1124: 1123: 1110: 1100: 1078: 1018: 1015: 1014: 995: 992: 991: 975: 972: 971: 952: 949: 948: 928: 925: 924: 908: 905: 904: 875: 874: 856: 855: 847: 844: 843: 821: 818: 817: 801: 798: 797: 791: 760: 759: 757: 754: 753: 723: 722: 720: 717: 716: 687: 686: 684: 681: 680: 637: 636: 612: 609: 608: 581: 580: 556: 553: 552: 549:is defined by: 519: 518: 482: 479: 478: 471:vector addition 435: 434: 432: 429: 428: 412: 409: 408: 377: 369: 364: 362: 359: 358: 332: 331: 329: 326: 325: 296: 295: 293: 290: 289: 255: 254: 252: 249: 248: 232: 224: 219: 211: 208: 207: 173: 165: 160: 158: 155: 154: 120: 119: 117: 114: 113: 76: 73: 72: 69: 23: 22: 15: 12: 11: 5: 1147: 1137: 1136: 1122: 1121: 1116: 1109: 1106: 1105: 1104: 1098: 1077: 1074: 1058: 1057: 1046: 1043: 1040: 1037: 1034: 1031: 1028: 1025: 1022: 999: 979: 959: 956: 947:vertices. Let 932: 912: 901: 900: 889: 886: 883: 878: 873: 870: 867: 864: 859: 854: 851: 825: 805: 790: 787: 774: 771: 768: 763: 737: 734: 731: 726: 701: 698: 695: 690: 665: 664: 663: 662: 651: 648: 645: 640: 635: 632: 628: 625: 622: 619: 616: 606: 595: 592: 589: 584: 579: 576: 572: 569: 566: 563: 560: 544: 533: 530: 527: 522: 517: 514: 511: 508: 504: 501: 498: 495: 492: 489: 486: 468: 449: 446: 443: 438: 416: 380: 376: 372: 367: 346: 343: 340: 335: 310: 307: 304: 299: 269: 266: 263: 258: 235: 231: 227: 222: 218: 215: 195: 192: 189: 186: 183: 180: 176: 172: 168: 163: 134: 131: 128: 123: 98: 95: 92: 89: 86: 83: 80: 68: 65: 61:linear algebra 31:discipline of 9: 6: 4: 3: 2: 1146: 1135: 1132: 1131: 1129: 1120: 1117: 1115: 1112: 1111: 1101: 1099:3-540-26182-6 1095: 1091: 1087: 1086: 1080: 1079: 1073: 1071: 1067: 1063: 1044: 1041: 1038: 1035: 1029: 1026: 1020: 1013: 1012: 1011: 997: 977: 957: 954: 946: 930: 910: 884: 865: 852: 849: 842: 841: 840: 839: 823: 803: 796: 786: 769: 751: 732: 713: 696: 678: 674: 670: 646: 633: 630: 626: 623: 620: 617: 614: 607: 590: 577: 574: 567: 564: 561: 558: 551: 550: 548: 545: 528: 515: 512: 509: 506: 502: 496: 493: 490: 487: 484: 476: 472: 469: 467: 463: 444: 414: 406: 405: 404: 401: 399: 395: 374: 370: 341: 324: 305: 287: 283: 264: 229: 225: 213: 190: 187: 184: 178: 170: 166: 152: 148: 129: 112: 93: 90: 87: 81: 78: 64: 62: 58: 54: 50: 49:vector spaces 46: 42: 38: 34: 30: 19: 1085:Graph Theory 1084: 1059: 902: 816:for a graph 792: 749: 714: 672: 666: 465: 402: 393: 322: 285: 281: 151:finite field 146: 111:vertex space 110: 70: 41:vertex space 40: 36: 33:graph theory 29:mathematical 26: 18:Vertex space 1114:Cycle space 1062:cycle space 671:subsets of 37:edge space 1076:References 789:Properties 323:edge space 67:Definition 1119:Cut space 1070:subspaces 1066:cut space 872:→ 669:singleton 634:∈ 618:⋅ 578:∈ 571:∅ 562:⋅ 516:∈ 500:△ 462:power set 398:dimension 217:→ 1128:Category 1108:See also 1090:Springer 1064:and the 945:incident 675:form a 460:is the 357:is the 27:In the 1096:  396:. The 57:vertex 43:of an 35:, the 1010:then 677:basis 1094:ISBN 1068:are 1060:The 990:and 793:The 679:for 667:The 71:Let 55:and 53:edge 47:are 39:and 464:of 145:of 1130:: 1092:, 785:. 712:. 624::= 568::= 494::= 477:: 179::= 82::= 1045:u 1042:+ 1039:v 1036:= 1033:) 1030:u 1027:v 1024:( 1021:H 998:u 978:v 958:u 955:v 931:G 911:G 888:) 885:G 882:( 877:V 869:) 866:G 863:( 858:E 853:: 850:H 824:G 804:H 773:) 770:G 767:( 762:E 750:V 736:) 733:G 730:( 725:V 700:) 697:G 694:( 689:E 673:E 650:) 647:G 644:( 639:E 631:P 627:P 621:P 615:1 594:) 591:G 588:( 583:E 575:P 565:P 559:0 532:) 529:G 526:( 521:E 513:Q 510:, 507:P 503:Q 497:P 491:Q 488:+ 485:P 466:E 448:) 445:G 442:( 437:E 415:E 394:E 379:Z 375:2 371:/ 366:Z 345:) 342:G 339:( 334:E 309:) 306:G 303:( 298:V 286:V 282:V 268:) 265:G 262:( 257:V 234:Z 230:2 226:/ 221:Z 214:V 194:} 191:1 188:, 185:0 182:{ 175:Z 171:2 167:/ 162:Z 147:G 133:) 130:G 127:( 122:V 97:) 94:E 91:, 88:V 85:( 79:G 20:)

Index

Vertex space
mathematical
graph theory
undirected graph
vector spaces
edge
vertex
linear algebra
finite field
dimension
power set
vector addition
symmetric difference
scalar multiplication
singleton
basis
incidence matrix
linear transformation
incident
cycle space
cut space
subspaces
Graph Theory
Springer
ISBN
3-540-26182-6
Cycle space
Cut space
Category
Algebraic graph theory

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