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Unknot

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It can be difficult to find a way to untangle string even though the fact it started out untangled proves the task is possible. Thistlethwaite and Ochiai provided many examples of diagrams of unknots that have no obvious way to simplify them, requiring one to temporarily increase the diagram's
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While rope is generally not in the form of a closed loop, sometimes there is a canonical way to imagine the ends being joined together. From this point of view, many useful practical knots are actually the unknot, including those that can be tied in a
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is a particular unknotted linkage that cannot be reconfigured into a flat convex polygon. Like crossing number, a linkage might need to be made more complex by subdividing its segments before it can be simplified.
611: 628:(both of which have 11 crossings) have the same Alexander and Conway polynomials as the unknot. It is an open problem whether any non-trivial knot has the same Jones polynomial as the unknot. 441:
detect the unknot, but these are not known to be efficiently computable for this purpose. It is not known whether the Jones polynomial or
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is the minimal number of segments needed to represent a knot as a linkage, and a
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Deciding if a particular knot is the unknot was a major driving force behind
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The unknot is the only knot that is the boundary of an embedded
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tied into it, unknotted. To a knot theorist, an unknot is any
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Similarly, the unknot is the 330:Two simple diagrams of the unknot 1509:Non-tricolorable knots and links 1445: 1434: 1433: 478: 463: 31: 1479:Non-alternating knots and links 616:No other knot with 10 or fewer 584: 562: 42:needs additional citations for 1300:Dowker–Thistlethwaite notation 712: 594: 588: 572: 566: 550: 544: 13: 1: 768:. Accessed: May 7, 2013. 679: 518: 737:(2): 301–306. Archived from 336:mathematical theory of knots 7: 654: 531:of the unknot are trivial: 525:Alexander–Conway polynomial 448: 129:Loop seen as a trivial knot 10: 1530: 403: 1429: 1333: 1290:Alexander–Briggs notation 1277: 1112: 1014: 979: 837: 301: 296: 281: 271: 258: 248: 238: 228: 218: 208: 198: 188: 178: 168: 158: 148: 139: 134: 502:can be represented as a 1489:Fibered knots and links 1381:List of knots and links 929:Kinoshita–Terasaka knot 622:Kinoshita–Terasaka knot 485:One of Ochiai's unknots 445:can detect the unknot. 607: 443:finite type invariants 331: 1499:Slice knots and links 1494:Prime knots and links 1484:Torus knots and links 1171:Finite type invariant 608: 329: 538: 416:recognize the unknot 392:with respect to the 51:improve this article 1341:Alexander's theorem 435:knot Floer homology 774:Weisstein, Eric W. 720:Godfried Toussaint 661:Knot (mathematics) 603: 406:Unknotting problem 400:Unknotting problem 359:topological circle 332: 1461: 1460: 1315:Reidemeister move 1181:Khovanov homology 1176:Hyperbolic volume 673:Unknotting number 439:Khovanov homology 433:It is known that 324: 323: 319:fully amphichiral 127: 126: 119: 101: 16:(Redirected from 1521: 1449: 1448: 1437: 1436: 1401:Tait conjectures 1104: 1103: 1089: 1088: 1074: 1073: 966: 965: 951: 950: 935:(−2,3,7) pretzel 815: 808: 801: 792: 791: 787: 786: 746: 745: 743: 728: 716: 710: 709: 707: 706: 697:. Archived from 690: 612: 610: 609: 604: 529:Jones polynomial 482: 467: 390:identity element 367:ambient isotopic 144: 132: 131: 122: 115: 111: 108: 102: 100: 59: 35: 27: 21: 1529: 1528: 1524: 1523: 1522: 1520: 1519: 1518: 1464: 1463: 1462: 1457: 1425: 1329: 1295:Conway notation 1279: 1273: 1260:Tricolorability 1108: 1102: 1099: 1098: 1097: 1087: 1084: 1083: 1082: 1072: 1069: 1068: 1067: 1059: 1049: 1039: 1029: 1010: 989:Composite knots 975: 964: 961: 960: 959: 956:Borromean rings 949: 946: 945: 944: 918: 908: 898: 888: 880: 872: 862: 852: 833: 819: 755: 750: 749: 741: 726: 717: 713: 704: 702: 695:"Knotty topics" 693:Volker Schatz. 691: 687: 682: 657: 641:knot complement 635:is an infinite 539: 536: 535: 521: 486: 483: 474: 468: 456:crossing number 451: 412:knot invariants 408: 402: 375:standard unknot 291: 273:Dowker notation 267: 250:Conway notation 130: 123: 112: 106: 103: 60: 58: 48: 36: 23: 22: 15: 12: 11: 5: 1527: 1517: 1516: 1511: 1506: 1501: 1496: 1491: 1486: 1481: 1476: 1459: 1458: 1456: 1455: 1443: 1430: 1427: 1426: 1424: 1423: 1421:Surgery theory 1418: 1413: 1408: 1403: 1398: 1393: 1388: 1383: 1378: 1373: 1368: 1363: 1358: 1353: 1348: 1343: 1337: 1335: 1331: 1330: 1328: 1327: 1322: 1320:Skein relation 1317: 1312: 1307: 1302: 1297: 1292: 1286: 1284: 1275: 1274: 1272: 1271: 1265:Unknotting no. 1262: 1257: 1252: 1251: 1250: 1240: 1235: 1234: 1233: 1228: 1223: 1218: 1213: 1203: 1198: 1193: 1188: 1183: 1178: 1173: 1168: 1163: 1158: 1157: 1156: 1146: 1141: 1140: 1139: 1129: 1124: 1118: 1116: 1110: 1109: 1107: 1106: 1100: 1091: 1085: 1076: 1070: 1061: 1057: 1051: 1047: 1041: 1037: 1031: 1027: 1020: 1018: 1012: 1011: 1009: 1008: 1003: 1002: 1001: 996: 985: 983: 977: 976: 974: 973: 968: 962: 953: 947: 938: 932: 926: 920: 916: 910: 906: 900: 896: 890: 886: 882: 878: 874: 870: 864: 860: 854: 850: 843: 841: 835: 834: 818: 817: 810: 803: 795: 789: 788: 769: 765:The Knot Atlas 754: 753:External links 751: 748: 747: 744:on 2003-05-12. 711: 684: 683: 681: 678: 677: 676: 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Retrieved 699:the original 688: 645:homeomorphic 637:cyclic group 630: 615: 522: 512:stuck unknot 508:stick number 497: 489: 452: 432: 420:knot diagram 409: 379: 374: 348:trivial knot 347: 343: 339: 333: 260:A–B notation 190:Crossing no. 113: 104: 94: 87: 80: 73: 61: 49:Please help 44:verification 41: 18:Trivial knot 1474:Knot theory 1201:Linking no. 1122:Alternating 923:Conway knot 903:Carrick mat 857:Three-twist 822:Knot theory 649:solid torus 626:Conway knot 396:operation. 210:Linking no. 149:Common name 1468:Categories 1361:Complement 1325:Tabulation 1282:operations 1206:Polynomial 1196:Link group 1191:Knot group 1154:Invertible 1132:Bridge no. 1114:Invariants 1044:Cinquefoil 913:Perko pair 839:Hyperbolic 705:2007-04-23 680:References 639:, and its 633:knot group 519:Invariants 230:Tunnel no. 180:Bridge no. 77:newspapers 1255:Stick no. 1211:Alexander 1149:Chirality 1094:Solomon's 1054:Septafoil 981:Satellite 941:Whitehead 867:Stevedore 782:MathWorld 618:crossings 564:∇ 542:Δ 500:tame knot 220:Stick no. 170:Braid no. 1440:Category 1310:Mutation 1278:Notation 1231:Kauffman 1144:Brunnian 1137:2-bridge 1006:Knot sum 937:(12n242) 777:"Unknot" 722:(2001). 655:See also 449:Examples 394:knot sum 365:that is 363:3-sphere 356:embedded 344:not knot 66:"Unknot" 1514:Circles 1452:Commons 1371:Fibered 1269:problem 1238:Pretzel 1216:Bracket 1034:Trefoil 971:L10a140 931:(11n42) 925:(11n34) 893:Endless 504:linkage 361:in the 334:In the 307:fibered 91:scholar 1416:Writhe 1386:Ribbon 1221:HOMFLY 1064:Unlink 1024:Unknot 999:Square 994:Granny 760:Unknot 667:Unlink 498:Every 473:unknot 373:, the 371:circle 340:unknot 338:, the 317:, 313:, 309:, 305:, 153:Circle 135:Unknot 93:  86:  79:  72:  64:  1406:Twist 1391:Slice 1346:Berge 1334:Other 1305:Flype 1243:Prime 1226:Jones 1186:Genus 1016:Torus 830:links 826:knots 742:(PDF) 727:(PDF) 647:to a 493:bight 428:co-NP 346:, or 315:slice 311:prime 303:torus 297:Other 200:Genus 98:JSTOR 84:books 1411:Wild 1376:Knot 1280:and 1267:and 1248:list 1079:Hopf 828:and 624:and 527:and 523:The 437:and 426:and 382:disk 352:knot 283:Next 70:news 1396:Sum 917:161 915:(10 762:", 643:is 53:by 1470:: 1096:(4 1081:(2 1066:(0 1056:(7 1046:(5 1036:(3 1026:(0 958:(6 943:(5 907:18 905:(8 895:(7 869:(6 859:(5 849:(4 779:. 735:42 733:. 729:. 651:. 601:1. 495:. 458:. 430:. 424:NP 377:. 342:, 1105:) 1101:1 1090:) 1086:1 1075:) 1071:1 1060:) 1058:1 1050:) 1048:1 1040:) 1038:1 1030:) 1028:1 967:) 963:2 952:) 948:1 919:) 909:) 899:) 897:4 887:3 885:6 879:2 877:6 873:) 871:1 863:) 861:2 853:) 851:1 832:) 824:( 814:e 807:t 800:v 785:. 758:" 708:. 598:= 595:) 592:q 589:( 586:V 582:, 579:1 576:= 573:) 570:z 567:( 560:, 557:1 554:= 551:) 548:t 545:( 290:1 288:3 277:- 266:1 264:0 254:- 244:0 234:0 224:3 214:0 204:0 194:0 184:0 174:1 164:0 120:) 114:( 109:) 105:( 95:· 88:· 81:· 74:· 47:. 20:)

Index

Trivial knot

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Circle
Arf invariant
Braid no.
Bridge no.
Crossing no.
Genus
Linking no.
Stick no.
Tunnel no.
Unknotting no.
Conway notation
A–B notation
Dowker notation
Next
31
torus
fibered

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