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Heawood graph

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There are 28 six-vertex cycles in the Heawood graph. Each 6-cycle is disjoint from exactly three other 6-cycles; among these three 6-cycles, each one is the symmetric difference of the other two. The graph with one node per 6-cycle, and one edge for each disjoint pair of 6-cycles, is the
293:. For instance, the figure shows the vertices of the graph placed on a cycle, with the internal diagonals of the cycle forming a matching. By subdividing the cycle edges into two matchings, we can partition the Heawood graph into three perfect matchings (that is, 484:: it can be embedded in the plane such that adjacent vertices are exactly at distance one apart, with no two vertices embedded to the same point and no vertex embedded into a point within an edge. 608: 430:, the graph representing incidences between points and lines in that geometry. With this interpretation, the 6-cycles in the Heawood graph correspond to 297:) in eight different ways. Every two perfect matchings, and every two Hamiltonian cycles, can be transformed into each other by a symmetry of the graph. 1012: 776: 464: 685: 504:(7), a group of order 336. It acts transitively on the vertices, on the edges and on the arcs of the graph. Therefore, the Heawood graph is a 1082: 774:
Abreu, M.; Aldred, R. E. L.; Funk, M.; Jackson, Bill; Labbate, D.; Sheehan, J. (2004), "Graphs and digraphs with all 2-factors isomorphic",
222: 471: 508:. It has automorphisms that take any vertex to any other vertex and any edge to any other edge. More strongly, the Heawood graph is 1096: 865: 692: 1152: 898: 861: 627: 454: 262:, and all cycles in the graph have six or more edges. Every smaller cubic graph has shorter cycles, so this graph is the 6- 675: 636: 1170:
and Dobcsányi, P. "Trivalent Symmetric Graphs Up to 768 Vertices." J. Combin. Math. Combin. Comput. 40, 41-63, 2002.
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in 1890, who proved that no map on the torus could require more than seven colors and thus this map is maximal.
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Additions and Corrections to the book Distance-Regular Graphs (Brouwer, Cohen, Neumaier; Springer; 1989)
64: 1056: 906: 267: 104: 707: 481: 359: 263: 193: 74: 1046: 955: 923: 840: 822: 493: 352: 247: 114: 57: 1102: 1088: 467:). Including the Heawood graph, there are 8 distinct graphs of order 14 with crossing number 3. 1092: 1074: 729: 394: 290: 209: 1021: 915: 880: 832: 785: 657: 516:, the Heawood graph, referenced as F014A, is the only cubic symmetric graph on 14 vertices. 286: 243: 132: 799: 1156: 1124: 795: 756: 642: 509: 505: 412: 326: 313: 213: 185: 162: 152: 142: 1149: 1060: 1167: 1078: 520: 322: 205: 28: 289:
in the Heawood graph; for each matching, the set of edges not in the matching forms a
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Heawood's map. Opposite edges of the large hexagon are connected to form a torus.
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faces. Each face of the map is adjacent to every other face, thus as a result
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3, and is the smallest cubic graph with that crossing number (sequence
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Dejter, Italo J. (2011), "From the Coxeter graph to the Klein graph",
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the map requires 7 colors. The map and graph were discovered by
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Eleven unit distance embeddings of the Heawood graph
470:The Heawood graph is the smallest cubic graph with 181: 171: 161: 151: 141: 131: 113: 103: 93: 83: 73: 63: 53: 39: 602: 434:in the Fano plane. Also, the Heawood graph is the 31:, a graph family that contains the Heawood graph. 1183:. Master Thesis, University of Tübingen, 2018 1150:"Cubic Symmetric Graphs (The Foster Census)." 873:Bulletin of the American Mathematical Society 866:"Self-dual configurations and regular graphs" 8: 1005:"Graphs and obstructions in four dimensions" 366:such that every pair of faces is adjacent. 362:, the only known polyhedron apart from the 246:with 14 vertices and 21 edges, named after 1123:Conder, Marston; Morton, Margaret (1995). 496:of the Heawood graph is isomorphic to the 358:The map can be faithfully realized as the 1050: 1025: 1013:Journal of Combinatorial Theory, Series B 856: 854: 826: 789: 777:Journal of Combinatorial Theory, Series B 751: 749: 594: 578: 539: 720: 617: 603:{\displaystyle (x-3)(x+3)(x^{2}-2)^{6}} 36: 1132:Australasian Journal of Combinatorics 7: 309:Geometric and topological properties 1181:Engineering Linear Layouts with SAT 1087:. New York: North Holland. p.  1041:Gerbracht, Eberhard H.-A. (2009), 25: 472:Colin de Verdière graph invariant 34:Undirected graph with 14 vertices 960:Quarterly Journal of Mathematics 700: 684: 665: 650: 635: 620: 393: 382: 373: 45: 885:10.1090/S0002-9904-1950-09407-5 406:and two representations of its 1084:Graph Theory with Applications 958:(1890). "Map-colour theorem". 591: 571: 568: 556: 553: 541: 266:, the smallest cubic graph of 223:Table of graphs and parameters 1: 691:embedded in a torus (compare 27:Not to be confused with the 1003:Hein van der Holst (2006). 899:"The many names of (7,3,1)" 1221: 1027:10.1016/j.jctb.2005.09.004 791:10.1016/j.jctb.2004.09.004 26: 532:characteristic polynomial 422:The Heawood graph is the 329:without crossings onto a 272:distance-transitive graph 221: 44: 977:Szilassi, Lajos (1986), 534:of the Heawood graph is 254:Combinatorial properties 815:Journal of Graph Theory 498:projective linear group 480:The Heawood graph is a 321:The Heawood graph is a 604: 453:The Heawood graph has 318: 605: 325:; that is, it can be 316: 907:Mathematics Magazine 897:Brown, Ezra (2002). 672:embedded in a torus 538: 488:Algebraic properties 333:. The result is the 1061:2009arXiv0912.5395G 986:Structural Topology 757:Brouwer, Andries E. 708:Szilassi polyhedron 512:. According to the 482:unit distance graph 360:Szilassi polyhedron 198:Distance-transitive 1155:2008-07-20 at the 730:Weisstein, Eric W. 600: 494:automorphism group 353:Percy John Heawood 319: 248:Percy John Heawood 58:Percy John Heawood 1200:Individual graphs 979:"Regular toroids" 837:10.1002/jgt.20597 679: 676:shown as a square 416: 295:3-color its edges 291:Hamiltonian cycle 287:perfect matchings 228: 227: 217:Orientably simple 16:(Redirected from 1212: 1184: 1177: 1171: 1165: 1159: 1146: 1140: 1139: 1129: 1120: 1114: 1113: 1111: 1110: 1101:. Archived from 1071: 1065: 1063: 1054: 1038: 1032: 1031: 1029: 1009: 1000: 994: 993: 983: 974: 968: 967: 962:. First Series. 952: 946: 945: 943: 942: 936: 930:. Archived from 903: 894: 888: 887: 870: 858: 849: 847: 830: 810: 804: 802: 793: 771: 765: 763: 753: 744: 743: 742: 725: 704: 688: 673: 669: 658:chromatic number 654: 639: 624: 609: 607: 606: 601: 599: 598: 583: 582: 510:4-arc-transitive 476: 462: 410: 397: 386: 377: 342: 280:distance regular 278:) and therefore 244:undirected graph 202:Distance-regular 133:Chromatic number 49: 37: 21: 1220: 1219: 1215: 1214: 1213: 1211: 1210: 1209: 1190: 1189: 1188: 1187: 1178: 1174: 1166: 1162: 1157:Wayback Machine 1147: 1143: 1127: 1122: 1121: 1117: 1108: 1106: 1099: 1079:Murty, U. S. R. 1073: 1072: 1068: 1040: 1039: 1035: 1007: 1002: 1001: 997: 981: 976: 975: 971: 954: 953: 949: 940: 938: 934: 920:10.2307/3219140 901: 896: 895: 891: 868: 860: 859: 852: 812: 811: 807: 773: 772: 768: 760:"Heawood graph" 755: 754: 747: 733:"Heawood Graph" 728: 727: 726: 722: 717: 710: 705: 696: 689: 680: 670: 661: 655: 646: 643:chromatic index 640: 631: 628:crossing number 625: 616: 590: 574: 536: 535: 506:symmetric graph 503: 490: 474: 458: 455:crossing number 447: 443: 420: 419: 418: 417: 413:bipartite graph 400: 399: 398: 389: 388: 387: 379: 378: 341: 337: 311: 256: 216: 212: 208: 204: 200: 196: 192: 188: 143:Chromatic index 124: 35: 32: 23: 22: 15: 12: 11: 5: 1218: 1216: 1208: 1207: 1205:Regular graphs 1202: 1192: 1191: 1186: 1185: 1179:Jessica Wolz, 1172: 1160: 1141: 1115: 1097: 1066: 1033: 1020:(3): 388–404. 995: 969: 956:Heawood, P. J. 947: 889: 850: 805: 784:(2): 395–404, 766: 745: 719: 718: 716: 713: 712: 711: 706: 699: 697: 690: 683: 681: 671: 664: 662: 656: 649: 647: 641: 634: 632: 626: 619: 615: 612: 597: 593: 589: 586: 581: 577: 573: 570: 567: 564: 561: 558: 555: 552: 549: 546: 543: 521:book thickness 501: 489: 486: 445: 441: 402: 401: 392: 391: 390: 381: 380: 372: 371: 370: 369: 368: 339: 323:toroidal graph 310: 307: 255: 252: 226: 225: 219: 218: 183: 179: 178: 175: 169: 168: 165: 163:Book thickness 159: 158: 155: 149: 148: 145: 139: 138: 135: 129: 128: 122: 117: 111: 110: 107: 101: 100: 97: 91: 90: 87: 81: 80: 77: 71: 70: 67: 61: 60: 55: 51: 50: 42: 41: 33: 29:Heawood graphs 24: 14: 13: 10: 9: 6: 4: 3: 2: 1217: 1206: 1203: 1201: 1198: 1197: 1195: 1182: 1176: 1173: 1169: 1164: 1161: 1158: 1154: 1151: 1145: 1142: 1137: 1133: 1126: 1119: 1116: 1105:on 2010-04-13 1104: 1100: 1098:0-444-19451-7 1094: 1090: 1086: 1085: 1080: 1076: 1070: 1067: 1062: 1058: 1053: 1048: 1044: 1037: 1034: 1028: 1023: 1019: 1015: 1014: 1006: 999: 996: 991: 987: 980: 973: 970: 965: 961: 957: 951: 948: 937:on 2012-02-05 933: 929: 925: 921: 917: 913: 909: 908: 900: 893: 890: 886: 882: 878: 874: 867: 863: 857: 855: 851: 846: 842: 838: 834: 829: 824: 820: 816: 809: 806: 801: 797: 792: 787: 783: 779: 778: 770: 767: 761: 758: 752: 750: 746: 740: 739: 734: 731: 724: 721: 714: 709: 703: 698: 694: 687: 682: 677: 668: 663: 659: 653: 648: 644: 638: 633: 629: 623: 618: 613: 611: 595: 587: 584: 579: 575: 565: 562: 559: 550: 547: 544: 533: 528: 526: 522: 517: 515: 514:Foster census 511: 507: 499: 495: 487: 485: 483: 478: 473: 468: 466: 461: 456: 451: 449: 438:of the group 437: 436:Tits building 433: 429: 425: 414: 409: 405: 396: 385: 376: 367: 365: 361: 356: 354: 350: 346: 336: 332: 328: 324: 315: 308: 306: 304: 303:Coxeter graph 298: 296: 292: 288: 285:There are 24 283: 281: 277: 276:Foster census 273: 269: 265: 261: 258:The graph is 253: 251: 249: 245: 241: 240:Heawood graph 237: 233: 224: 220: 215: 211: 207: 203: 199: 195: 191: 187: 184: 180: 176: 174: 170: 166: 164: 160: 156: 154: 150: 146: 144: 140: 136: 134: 130: 126: 118: 116: 115:Automorphisms 112: 108: 106: 102: 98: 96: 92: 88: 86: 82: 78: 76: 72: 68: 66: 62: 59: 56: 52: 48: 43: 40:Heawood graph 38: 30: 19: 1180: 1175: 1163: 1144: 1135: 1131: 1118: 1107:. Retrieved 1103:the original 1083: 1075:Bondy, J. A. 1069: 1042: 1036: 1017: 1011: 998: 989: 985: 972: 963: 959: 950: 939:. Retrieved 932:the original 914:(2): 83–94. 911: 905: 892: 876: 872: 818: 814: 808: 781: 775: 769: 736: 723: 529: 525:queue number 518: 491: 479: 469: 452: 421: 411:(below as a 357: 320: 299: 284: 257: 239: 236:graph theory 232:mathematical 229: 173:Queue number 364:tetrahedron 335:regular map 270:6. It is a 210:Hamiltonian 54:Named after 18:Heawood map 1194:Categories 1168:Conder, M. 1148:Royle, G. 1109:2019-12-18 966:: 322–339. 941:2006-10-27 715:References 428:Fano plane 424:Levi graph 408:Levi graph 404:Fano plane 182:Properties 1052:0912.5395 828:1002.1960 738:MathWorld 585:− 548:− 432:triangles 345:hexagonal 343:, with 7 274:(see the 234:field of 214:Symmetric 186:Bipartite 1153:Archived 1081:(1976). 864:(1950), 349:coloring 327:embedded 206:Toroidal 95:Diameter 65:Vertices 1057:Bibcode 992:: 69–80 928:3219140 862:Coxeter 821:: 1–9, 800:2099150 614:Gallery 519:It has 463:in the 460:A110507 426:of the 230:In the 1138:: 146. 1095:  926:  845:754481 843:  798:  523:3 and 242:is an 238:, the 85:Radius 1128:(PDF) 1047:arXiv 1008:(PDF) 982:(PDF) 935:(PDF) 924:JSTOR 902:(PDF) 869:(PDF) 841:S2CID 823:arXiv 693:video 475:μ = 6 338:{6,3} 331:torus 268:girth 260:cubic 190:Cubic 153:Genus 119:336 ( 105:Girth 75:Edges 1093:ISBN 530:The 492:The 465:OEIS 264:cage 194:Cage 1089:237 1022:doi 916:doi 881:doi 833:doi 786:doi 527:2. 500:PGL 340:2,1 125:(7) 121:PGL 1196:: 1136:11 1134:. 1130:. 1091:. 1077:; 1055:, 1045:, 1018:96 1016:. 1010:. 990:13 988:, 984:, 964:24 922:. 912:75 910:. 904:. 879:, 877:56 875:, 871:, 853:^ 839:, 831:, 819:70 817:, 796:MR 794:, 782:92 780:, 748:^ 735:. 477:. 450:. 444:(F 440:SL 305:. 282:. 250:. 79:21 69:14 1112:. 1064:. 1059:: 1049:: 1030:. 1024:: 944:. 918:: 883:: 848:. 835:: 825:: 803:. 788:: 762:. 741:. 695:) 678:) 674:( 660:2 645:3 630:3 596:6 592:) 588:2 580:2 576:x 572:( 569:) 566:3 563:+ 560:x 557:( 554:) 551:3 545:x 542:( 502:2 448:) 446:2 442:3 415:) 177:2 167:3 157:1 147:3 137:2 127:) 123:2 109:6 99:3 89:3 20:)

Index

Heawood map
Heawood graphs

Percy John Heawood
Vertices
Edges
Radius
Diameter
Girth
Automorphisms
PGL2(7)
Chromatic number
Chromatic index
Genus
Book thickness
Queue number
Bipartite
Cubic
Cage
Distance-transitive
Distance-regular
Toroidal
Hamiltonian
Symmetric
Table of graphs and parameters
mathematical
graph theory
undirected graph
Percy John Heawood
cubic

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