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Girth (graph theory)

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is the number of edges. A practical optimization is to limit the depth of the BFS to a depth that depends on the length of the smallest cycle discovered so far. Better algorithms are known in the case where the girth is even and when the graph is planar. In terms of lower bounds, computing the girth
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is the unique 8-cage. There may exist multiple cages for a given girth. For instance there are three nonisomorphic 10-cages, each with 70 vertices: the
178: 54:. For example, a 4-cycle (square) has girth 4. A grid has girth 4 as well, and a triangular mesh has girth 3. A graph with girth four or more is 757: 362:
Thought of as the least length of a non-trivial cycle, the girth admits natural generalisations as the 1-systole or higher systoles in
626: 393:, the matroid girth equals the girth of the underlying graph, while for a co-graphic matroid it equals the edge connectivity. 275: 130: 146: 230:
construction used to form the Grötzsch graph produces triangle-free graphs of arbitrarily large chromatic number.
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Explicit, though large, graphs with high girth and chromatic number can be constructed as certain
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Chang, Hsien-Chih; Lu, Hsueh-I. (2013). "Computing the Girth of a Planar Graph in Linear Time".
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of a graph are the lengths of a shortest odd cycle and shortest even cycle respectively.
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vertices, formed by choosing independently whether to include each edge with probability
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Cho, Jung Jin; Chen, Yong; Ding, Yu (2007), "On the (co)girth of a connected matroid",
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contained in the graph. If the graph does not contain any cycles (that is, it is a
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is the unique 5-cage (it is the smallest cubic graph of girth 5), the
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is triangle-free and has chromatic number 4, and repeating the
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The girth of an undirected graph can be computed by running a
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Völkel, Christoph Dürr, Louis Abraham and Finn (2016-11-06).
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Elementary number theory, group theory, and Ramanujan graphs
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was the first to prove the general result, using the
469: 449: 429: 27:Length of a shortest cycle contained in the graph 381:, and vice versa. These concepts are unified in 478:of a graph is at least as hard as solving the 8: 742:: CS1 maint: multiple names: authors list ( 687:"Question 3: Computing the girth of a graph" 762:Theoretical Computer Science Stack Exchange 457:is the number of vertices of the graph and 210:, there exists a graph with girth at least 80:that is as small as possible is known as a 501:, p.8. 3rd Edition, Springer-Verlag, 2005 359:(simple) cycle, rather than the shortest. 76:(all vertices have degree three) of girth 794: 662: 576: 462: 442: 410: 563:(1959), "Graph theory and probability", 252:, has, with probability tending to 1 as 490: 126: 735: 7: 546:. Electronic supplement to the book 373:, in the sense that the girth of a 238:. More precisely, he showed that a 25: 405:from each node, with complexity 377:is the edge connectivity of its 355:of a graph is the length of the 177: 161: 145: 129: 565:Canadian Journal of Mathematics 424: 415: 50:), its girth is defined to be 1: 369:Girth is the dual concept to 108:is the unique 7-cage and the 651:Discrete Applied Mathematics 42:is the length of a shortest 18:Circumference (graph theory) 856: 256:goes to infinity, at most 202:For any positive integers 104:is the unique 6-cage, the 65: 783:SIAM Journal on Computing 664:10.1016/j.dam.2007.06.015 607:; Valette, Alain (2003), 619:10.1017/CBO9780511615825 480:triangle finding problem 303:colors in any coloring. 198:Girth and graph coloring 548:Distance-Regular Graphs 578:10.4153/CJM-1959-003-9 471: 451: 431: 472: 452: 432: 430:{\displaystyle O(nm)} 326:expansion coefficient 461: 441: 409: 403:breadth-first search 274:or less, but has no 236:probabilistic method 222:; for instance, the 537:Brouwer, Andries E. 318:. These remarkable 186:Tutte–Coxeter graph 68:Cage (graph theory) 699:on August 29, 2017 601:Davidoff, Giuliana 513:Weisstein, Eric W. 467: 447: 427: 387:girth of a matroid 192:) has a girth of 8 122:Harries–Wong graph 805:10.1137/110832033 657:(18): 2456–2470, 470:{\displaystyle m} 450:{\displaystyle n} 371:edge connectivity 364:systolic geometry 270:cycles of length 16:(Redirected from 847: 840:Graph invariants 825: 824: 798: 789:(3): 1077–1094. 778: 772: 771: 769: 768: 754: 748: 747: 741: 733: 731: 730: 720:"Shortest cycle" 715: 709: 708: 706: 704: 698: 692:. Archived from 691: 683: 677: 675: 666: 646: 640: 639: 597: 591: 589: 580: 557: 551: 545: 533: 527: 526: 525: 508: 502: 495: 476: 474: 473: 468: 456: 454: 453: 448: 436: 434: 433: 428: 353: 352: 332:Related concepts 324:also have large 321:Ramanujan graphs 302: 298: 294: 293: 292: 285: 273: 269: 268: 267: 263: 255: 251: 245: 221: 216:chromatic number 213: 209: 205: 190:Tutte eight cage 181: 172:has a girth of 7 165: 156:has a girth of 6 149: 140:has a girth of 5 133: 110:Tutte eight cage 95: 83: 79: 40:undirected graph 21: 855: 854: 850: 849: 848: 846: 845: 844: 830: 829: 828: 780: 779: 775: 766: 764: 756: 755: 751: 734: 728: 726: 717: 716: 712: 702: 700: 696: 689: 685: 684: 680: 648: 647: 643: 629: 599: 598: 594: 559: 558: 554: 535: 534: 530: 511: 510: 509: 505: 496: 492: 488: 459: 458: 439: 438: 407: 406: 399: 391:graphic matroid 350: 349: 334: 300: 296: 287: 281: 280: 279: 276:independent set 271: 265: 259: 258: 257: 253: 247: 243: 219: 211: 207: 203: 200: 193: 182: 173: 166: 157: 150: 141: 134: 114:Balaban 10-cage 89: 81: 77: 70: 64: 28: 23: 22: 15: 12: 11: 5: 853: 851: 843: 842: 832: 831: 827: 826: 773: 749: 710: 678: 641: 627: 592: 552: 528: 503: 489: 487: 484: 482:on the graph. 466: 446: 426: 423: 420: 417: 414: 398: 395: 383:matroid theory 333: 330: 224:Grötzsch graph 199: 196: 195: 194: 183: 176: 174: 167: 160: 158: 151: 144: 142: 138:Petersen graph 135: 128: 98:Petersen graph 66:Main article: 63: 60: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 852: 841: 838: 837: 835: 822: 818: 814: 810: 806: 802: 797: 792: 788: 784: 777: 774: 763: 759: 753: 750: 745: 739: 725: 721: 714: 711: 695: 688: 682: 679: 674: 670: 665: 660: 656: 652: 645: 642: 638: 634: 630: 628:0-521-82426-5 624: 620: 616: 612: 611: 606: 605:Sarnak, Peter 602: 596: 593: 588: 584: 579: 574: 570: 566: 562: 556: 553: 549: 544: 543: 538: 532: 529: 524: 523: 518: 514: 507: 504: 500: 494: 491: 485: 483: 481: 464: 444: 421: 418: 412: 404: 396: 394: 392: 388: 384: 380: 376: 372: 367: 365: 360: 358: 354: 351:circumference 345: 343: 339: 331: 329: 327: 323: 322: 317: 316:finite fields 313: 312:linear groups 309: 308:Cayley graphs 304: 291: 284: 277: 262: 250: 241: 237: 233: 229: 225: 217: 197: 191: 187: 180: 175: 171: 164: 159: 155: 154:Heawood graph 148: 143: 139: 132: 127: 125: 123: 119: 118:Harries graph 115: 111: 107: 103: 102:Heawood graph 99: 96:-cage). The 93: 87: 75: 69: 61: 59: 57: 56:triangle-free 53: 49: 45: 41: 37: 33: 19: 786: 782: 776: 765:. Retrieved 761: 752: 727:. Retrieved 723: 713: 703:February 22, 701:. Retrieved 694:the original 681: 654: 650: 644: 609: 595: 568: 564: 555: 547: 541: 531: 520: 506: 499:Graph Theory 498: 497:R. Diestel, 493: 400: 375:planar graph 368: 361: 356: 348: 346: 341: 337: 335: 319: 305: 289: 282: 260: 248: 240:random graph 201: 189: 91: 71: 35: 32:graph theory 29: 561:ErdĹ‘s, Paul 397:Computation 228:Mycielskian 170:McGee graph 106:McGee graph 74:cubic graph 767:2023-02-22 729:2023-02-22 486:References 379:dual graph 342:even girth 232:Paul ErdĹ‘s 813:0097-5397 796:1104.4892 587:122784453 571:: 34–38, 522:MathWorld 338:odd girth 218:at least 88:(or as a 834:Category 738:cite web 278:of size 120:and the 52:infinity 821:2493979 724:TryAlgo 673:2365057 637:1989434 517:"Girth" 385:by the 357:longest 286:⁄ 264:⁄ 819:  811:  671:  635:  625:  585:  437:where 116:, the 48:forest 38:of an 34:, the 817:S2CID 791:arXiv 697:(PDF) 690:(PDF) 583:S2CID 542:Cages 314:over 62:Cages 44:cycle 36:girth 809:ISSN 744:link 705:2023 623:ISBN 347:The 340:and 336:The 214:and 206:and 184:The 168:The 152:The 136:The 86:cage 801:doi 659:doi 655:155 615:doi 573:doi 310:of 242:on 90:(3, 30:In 836:: 815:. 807:. 799:. 787:42 785:. 760:. 740:}} 736:{{ 722:. 669:MR 667:, 653:, 633:MR 631:, 621:, 603:; 581:, 569:11 567:, 539:, 519:, 515:, 366:. 328:. 124:. 72:A 58:. 823:. 803:: 793:: 770:. 746:) 732:. 707:. 676:. 661:: 617:: 590:. 575:: 465:m 445:n 425:) 422:m 419:n 416:( 413:O 301:k 297:g 290:k 288:2 283:n 272:g 266:2 261:n 254:n 249:n 244:n 220:χ 212:g 208:χ 204:g 188:( 94:) 92:g 84:- 82:g 78:g 20:)

Index

Circumference (graph theory)
graph theory
undirected graph
cycle
forest
infinity
triangle-free
Cage (graph theory)
cubic graph
cage
Petersen graph
Heawood graph
McGee graph
Tutte eight cage
Balaban 10-cage
Harries graph
Harries–Wong graph
The Petersen graph has a girth of 5
Petersen graph
The Heawood graph has a girth of 6
Heawood graph
The McGee graph has a girth of 7
McGee graph
The Tutte–Coxeter graph (Tutte eight cage) has a girth of 8
Tutte–Coxeter graph
chromatic number
Grötzsch graph
Mycielskian
Paul Erdős
probabilistic method

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