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Figure-eight knot (mathematics)

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1234: 249: 1224: 1214: 40: 2575: 2587: 1033: 512: 1206:, holds that 10 is the largest possible number of exceptional surgeries of any hyperbolic knot. However, it is not currently known whether the figure-eight knot is the only one that achieves the bound of 10. A well-known conjecture is that the bound (except for the two knots mentioned) is 6. 1073:. (Robert Riley and Troels Jørgensen, working independently of each other, had earlier shown that the figure-eight knot was hyperbolic by other means.) This construction, new at the time, led him to many powerful results and methods. For example, he was able to show that all but ten 1610: 736: 322: 1304: 725: 1139: 741: 327: 1613: 1618: 1616: 1612: 1611: 1551: 1617: 1385: 1449: 1028:{\displaystyle {\begin{aligned}G(x,y,z,t)=\ &(z(x^{2}+y^{2}+z^{2}+t^{2})+x(6x^{2}-2y^{2}-2z^{2}-2t^{2}),\\&\ tx{\sqrt {2}}+y(6x^{2}-2y^{2}-2z^{2}-2t^{2})).\end{aligned}}} 1664: 1615: 1169: 1604: 1574: 507:{\displaystyle {\begin{aligned}x&=\left(2+\cos {(2t)}\right)\cos {(3t)}\\y&=\left(2+\cos {(2t)}\right)\sin {(3t)}\\z&=\sin {(4t)}\end{aligned}}} 2638: 2643: 1148: 1088:
3-manifolds; these were the first such examples. Many more have been discovered by generalizing Thurston's construction to other knots and links.
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The figure-eight knot has genus 1 and is fibered. Therefore its complement fibers over the circle, the fibers being
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in a rope and then joining the ends together, in the most natural way, gives a model of the mathematical knot.
1712: 578: 2266: 1203: 57: 2591: 1400: 1194:, Dehn surgeries resulting in a non-hyperbolic 3-manifold; they have 10 and 7, respectively. A theorem of 2480: 2449: 1809: 1056: 1043:
The figure-eight knot has played an important role historically (and continues to do so) in the theory of
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The figure-eight knot is also the hyperbolic knot whose complement has the smallest possible
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of four. This makes it the knot with the third-smallest possible crossing number, after the
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is then a homeomorphism of the 2-torus, which can be represented in this case by the matrix
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A simple parametric representation of the figure-eight knot is as the set of all points (
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in the Jones polynomial reflects the fact that the figure-eight knot is achiral.
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varying over the real numbers (see 2D visual realization at bottom right).
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This article is about the mathematical concept. For the knot, see
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either occurs always with positive or always with negative sign.
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which are 2-dimensional tori with one boundary component. The
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The orientable cusped hyperbolic 3-manifolds of minimum volume
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are the only two hyperbolic knots known to have more than 6
1825:, Inventiones Mathematicae, 146 (2001), no. 3, 451–478. 1143: 252:
Figure-eight knot of practical knot-tying, with ends joined
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Simple squared depiction of figure-eight configuration.
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Symmetric depiction generated by parametric equations.
720:{\displaystyle F(x,y,z,t)=G(x,y,z^{2}-t^{2},2zt),\,\!} 1645: 1582: 1562: 1467: 1403: 1327: 1259: 1157: 1101: 739: 622: 574:
shows that any closed homogeneous braid is fibered.
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Mathematical surface Illustrating Figure-eight knot
1134:{\displaystyle 6\Lambda (\pi /3)\approx 2.02988...} 214: 188: 178: 165: 156: 146: 136: 126: 116: 106: 96: 86: 76: 66: 56: 46: 32: 1658: 1598: 1568: 1545: 1443: 1379: 1298: 1163: 1133: 1027: 719: 506: 1888:, Princeton University lecture notes (1978–1981). 1639:A braid is called homogeneous if every generator 716: 1860:The maximal number of exceptional Dehn surgeries 1546:{\displaystyle V(q)=q^{2}-q+1-q^{-1}+q^{-2}.\ } 1946: 8: 1885:The Geometry and Topology of Three-Manifolds 1752:The Geometry and Topology of Three-Manifolds 1688:"Listing knot - Encyclopedia of Mathematics" 554:(namely, the closure of the 3-string braid σ 1953: 1939: 1931: 38: 16:Unique knot with a crossing number of four 1650: 1644: 1587: 1581: 1561: 1528: 1512: 1487: 1466: 1429: 1402: 1380:{\displaystyle \Delta (t)=-t+3-t^{-1},\ } 1362: 1326: 1263: 1258: 1198:and Meyerhoff, whose proof relies on the 1156: 1114: 1100: 1077:on the figure-eight knot resulted in non- 1006: 990: 974: 958: 935: 909: 893: 877: 861: 836: 823: 810: 797: 740: 738: 715: 691: 678: 621: 486: 452: 427: 382: 357: 326: 324: 292:The name is given because tying a normal 1608: 536:with an associated value of 5/3, and is 247: 1679: 1632: 1047:. Sometime in the mid-to-late 1970s, 577:(2) It is the link at (0,0,0,0) of an 29: 1444:{\displaystyle \nabla (z)=1-z^{2},\ } 7: 2586: 1872:Problems in low-dimensional topology 1806:Bounds on exceptional Dehn filling 1404: 1328: 1158: 1105: 540:. The figure-eight knot is also a 14: 2639:Fully amphichiral knots and links 1713:"Rational Knots with 4 crossings" 1264: 1051:showed that the figure-eight was 2644:Non-tricolorable knots and links 2585: 2574: 2573: 593:, so (according to a theorem of 1821:Chun Cao and Robert Meyerhoff, 2440:Dowker–Thistlethwaite notation 1477: 1471: 1413: 1407: 1337: 1331: 1293: 1260: 1186:The figure-eight knot and the 1122: 1108: 1015: 1012: 948: 915: 851: 842: 790: 784: 771: 747: 709: 659: 650: 626: 496: 487: 462: 453: 437: 428: 392: 383: 367: 358: 1: 1755:, p. 165, archived from 280:. The figure-eight knot is a 2659:Double torus knots and links 1908:. Accessed: 7 May 2013. 1875:, (see problem 1.77, due to 1845:140 (2000), no. 2, 243–282. 1839:Word hyperbolic Dehn surgery 1318:of the figure-eight knot is 268:) is the unique knot with a 2619:Alternating knots and links 1659:{\displaystyle \sigma _{i}} 2675: 2624:Hyperbolic knots and links 1747:"7. Computation of volume" 605:is actually a fibration. 18: 2569: 2430:Alexander–Briggs notation 1879:, for exceptional slopes) 1200:geometrization conjecture 581:of a real-polynomial map 524:The figure-eight knot is 219: 37: 1843:Inventiones Mathematicae 1164:{\displaystyle \Lambda } 2629:Fibered knots and links 2521:List of knots and links 2069:Kinoshita–Terasaka knot 1810:Geometry & Topology 1717:Rational Knots database 1039:Mathematical properties 613:for this knot, namely, 579:isolated critical point 1857:and Robert Meyerhoff, 1692:encyclopediaofmath.org 1660: 1623: 1600: 1599:{\displaystyle q^{-1}} 1570: 1547: 1445: 1381: 1300: 1238: 1228: 1218: 1165: 1135: 1029: 721: 508: 253: 23:. For other uses, see 2634:Prime knots and links 2311:Finite type invariant 1661: 1621: 1601: 1571: 1556:The symmetry between 1548: 1446: 1382: 1301: 1236: 1226: 1216: 1192:exceptional surgeries 1188:(−2,3,7) pretzel knot 1166: 1136: 1030: 722: 609:found the first such 509: 251: 1812:4 (2000), 431–449. 1643: 1580: 1560: 1465: 1401: 1325: 1316:Alexander polynomial 1257: 1173:Lobachevsky function 1155: 1099: 737: 620: 570:), and a theorem of 323: 2481:Alexander's theorem 1917:"Figure Eight Knot" 1204:computer assistance 1914:Weisstein, Eric W. 1882:William Thurston, 1656: 1624: 1596: 1566: 1543: 1441: 1377: 1296: 1291: 1290: 1239: 1229: 1219: 1181:Gieseking manifold 1161: 1131: 1025: 1023: 717: 504: 502: 254: 2601: 2600: 2455:Reidemeister move 2321:Khovanov homology 2316:Hyperbolic volume 1863:, arXiv:0808.1176 1711:Gruber, Hermann. 1622:Figure-eight knot 1619: 1569:{\displaystyle q} 1542: 1440: 1392:Conway polynomial 1376: 1243: 1242: 940: 928: 779: 294:figure-eight knot 262:figure-eight knot 246: 245: 237:fully amphichiral 128:Hyperbolic volume 51:Figure-eight knot 33:Figure-eight knot 21:Figure-eight knot 2666: 2589: 2588: 2577: 2576: 2541:Tait conjectures 2244: 2243: 2229: 2228: 2214: 2213: 2106: 2105: 2091: 2090: 2075:(−2,3,7) pretzel 1955: 1948: 1941: 1932: 1927: 1926: 1789: 1776: 1770: 1769: 1768: 1767: 1761: 1743:William Thurston 1739: 1733: 1732: 1730: 1728: 1719:. Archived from 1708: 1702: 1701: 1699: 1698: 1684: 1667: 1665: 1663: 1662: 1657: 1655: 1654: 1637: 1620: 1605: 1603: 1602: 1597: 1595: 1594: 1575: 1573: 1572: 1567: 1552: 1550: 1549: 1544: 1540: 1536: 1535: 1520: 1519: 1492: 1491: 1456:Jones polynomial 1450: 1448: 1447: 1442: 1438: 1434: 1433: 1386: 1384: 1383: 1378: 1374: 1370: 1369: 1305: 1303: 1302: 1297: 1292: 1247:Seifert surfaces 1209: 1208: 1170: 1168: 1167: 1162: 1146: 1140: 1138: 1137: 1132: 1118: 1049:William Thurston 1034: 1032: 1031: 1026: 1024: 1011: 1010: 995: 994: 979: 978: 963: 962: 941: 936: 926: 924: 914: 913: 898: 897: 882: 881: 866: 865: 841: 840: 828: 827: 815: 814: 802: 801: 777: 726: 724: 723: 718: 696: 695: 683: 682: 513: 511: 510: 505: 503: 499: 465: 445: 441: 440: 395: 375: 371: 370: 193: 42: 30: 2674: 2673: 2669: 2668: 2667: 2665: 2664: 2663: 2604: 2603: 2602: 2597: 2565: 2469: 2435:Conway notation 2419: 2413: 2400:Tricolorability 2248: 2242: 2239: 2238: 2237: 2227: 2224: 2223: 2222: 2212: 2209: 2208: 2207: 2199: 2189: 2179: 2169: 2150: 2129:Composite knots 2115: 2104: 2101: 2100: 2099: 2096:Borromean rings 2089: 2086: 2085: 2084: 2058: 2048: 2038: 2028: 2020: 2012: 2002: 1992: 1973: 1959: 1912: 1911: 1895: 1798: 1796:Further reading 1793: 1792: 1777: 1773: 1765: 1763: 1759: 1741: 1740: 1736: 1726: 1724: 1710: 1709: 1705: 1696: 1694: 1686: 1685: 1681: 1676: 1671: 1670: 1646: 1641: 1640: 1638: 1634: 1629: 1609: 1583: 1578: 1577: 1558: 1557: 1524: 1508: 1483: 1463: 1462: 1425: 1399: 1398: 1358: 1323: 1322: 1312: 1289: 1288: 1283: 1277: 1276: 1271: 1255: 1254: 1153: 1152: 1142: 1097: 1096: 1083:Seifert-fibered 1041: 1022: 1021: 1002: 986: 970: 954: 922: 921: 905: 889: 873: 857: 832: 819: 806: 793: 780: 735: 734: 687: 674: 618: 617: 612: 604: 584: 569: 565: 561: 557: 501: 500: 473: 467: 466: 414: 410: 403: 397: 396: 344: 340: 333: 321: 320: 302: 290: 270:crossing number 209: 202: 191: 180:Dowker notation 174: 158:Conway notation 28: 17: 12: 11: 5: 2672: 2670: 2662: 2661: 2656: 2651: 2646: 2641: 2636: 2631: 2626: 2621: 2616: 2606: 2605: 2599: 2598: 2596: 2595: 2583: 2570: 2567: 2566: 2564: 2563: 2561:Surgery theory 2558: 2553: 2548: 2543: 2538: 2533: 2528: 2523: 2518: 2513: 2508: 2503: 2498: 2493: 2488: 2483: 2477: 2475: 2471: 2470: 2468: 2467: 2462: 2460:Skein relation 2457: 2452: 2447: 2442: 2437: 2432: 2426: 2424: 2415: 2414: 2412: 2411: 2405:Unknotting no. 2402: 2397: 2392: 2391: 2390: 2380: 2375: 2374: 2373: 2368: 2363: 2358: 2353: 2343: 2338: 2333: 2328: 2323: 2318: 2313: 2308: 2303: 2298: 2297: 2296: 2286: 2281: 2280: 2279: 2269: 2264: 2258: 2256: 2250: 2249: 2247: 2246: 2240: 2231: 2225: 2216: 2210: 2201: 2197: 2191: 2187: 2181: 2177: 2171: 2167: 2160: 2158: 2152: 2151: 2149: 2148: 2143: 2142: 2141: 2136: 2125: 2123: 2117: 2116: 2114: 2113: 2108: 2102: 2093: 2087: 2078: 2072: 2066: 2060: 2056: 2050: 2046: 2040: 2036: 2030: 2026: 2022: 2018: 2014: 2010: 2004: 2000: 1994: 1990: 1983: 1981: 1975: 1974: 1960: 1958: 1957: 1950: 1943: 1935: 1929: 1928: 1909: 1905:The Knot Atlas 1894: 1893:External links 1891: 1890: 1889: 1880: 1877:Cameron Gordon 1864: 1852: 1832: 1819: 1797: 1794: 1791: 1790: 1785:The Knot Atlas 1771: 1745:(March 2002), 1734: 1703: 1678: 1677: 1675: 1672: 1669: 1668: 1653: 1649: 1631: 1630: 1628: 1625: 1593: 1590: 1586: 1565: 1554: 1553: 1539: 1534: 1531: 1527: 1523: 1518: 1515: 1511: 1507: 1504: 1501: 1498: 1495: 1490: 1486: 1482: 1479: 1476: 1473: 1470: 1452: 1451: 1437: 1432: 1428: 1424: 1421: 1418: 1415: 1412: 1409: 1406: 1388: 1387: 1373: 1368: 1365: 1361: 1357: 1354: 1351: 1348: 1345: 1342: 1339: 1336: 1333: 1330: 1311: 1308: 1295: 1287: 1284: 1282: 1279: 1278: 1275: 1272: 1270: 1267: 1266: 1262: 1241: 1240: 1230: 1220: 1160: 1130: 1127: 1124: 1121: 1117: 1113: 1110: 1107: 1104: 1075:Dehn surgeries 1040: 1037: 1036: 1035: 1020: 1017: 1014: 1009: 1005: 1001: 998: 993: 989: 985: 982: 977: 973: 969: 966: 961: 957: 953: 950: 947: 944: 939: 934: 931: 925: 923: 920: 917: 912: 908: 904: 901: 896: 892: 888: 885: 880: 876: 872: 869: 864: 860: 856: 853: 850: 847: 844: 839: 835: 831: 826: 822: 818: 813: 809: 805: 800: 796: 792: 789: 786: 783: 781: 776: 773: 770: 767: 764: 761: 758: 755: 752: 749: 746: 743: 742: 728: 727: 714: 711: 708: 705: 702: 699: 694: 690: 686: 681: 677: 673: 670: 667: 664: 661: 658: 655: 652: 649: 646: 643: 640: 637: 634: 631: 628: 625: 610: 607:Bernard Perron 602: 582: 572:John Stallings 567: 563: 559: 555: 515: 514: 498: 495: 492: 489: 485: 482: 479: 476: 474: 472: 469: 468: 464: 461: 458: 455: 451: 448: 444: 439: 436: 433: 430: 426: 423: 420: 417: 413: 409: 406: 404: 402: 399: 398: 394: 391: 388: 385: 381: 378: 374: 369: 366: 363: 360: 356: 353: 350: 347: 343: 339: 336: 334: 332: 329: 328: 301: 298: 289: 288:Origin of name 286: 266:Listing's knot 244: 243: 217: 216: 212: 211: 207: 200: 196: 186: 185: 182: 176: 175: 172: 169: 163: 162: 160: 154: 153: 150: 148:Unknotting no. 144: 143: 140: 134: 133: 130: 124: 123: 120: 114: 113: 110: 104: 103: 100: 94: 93: 90: 84: 83: 80: 74: 73: 70: 64: 63: 60: 54: 53: 48: 44: 43: 35: 34: 15: 13: 10: 9: 6: 4: 3: 2: 2671: 2660: 2657: 2655: 2652: 2650: 2647: 2645: 2642: 2640: 2637: 2635: 2632: 2630: 2627: 2625: 2622: 2620: 2617: 2615: 2612: 2611: 2609: 2594: 2593: 2584: 2582: 2581: 2572: 2571: 2568: 2562: 2559: 2557: 2554: 2552: 2549: 2547: 2544: 2542: 2539: 2537: 2534: 2532: 2529: 2527: 2524: 2522: 2519: 2517: 2514: 2512: 2509: 2507: 2504: 2502: 2499: 2497: 2496:Conway sphere 2494: 2492: 2489: 2487: 2484: 2482: 2479: 2478: 2476: 2472: 2466: 2463: 2461: 2458: 2456: 2453: 2451: 2448: 2446: 2443: 2441: 2438: 2436: 2433: 2431: 2428: 2427: 2425: 2423: 2416: 2410: 2406: 2403: 2401: 2398: 2396: 2393: 2389: 2386: 2385: 2384: 2381: 2379: 2376: 2372: 2369: 2367: 2364: 2362: 2359: 2357: 2354: 2352: 2349: 2348: 2347: 2344: 2342: 2339: 2337: 2334: 2332: 2329: 2327: 2324: 2322: 2319: 2317: 2314: 2312: 2309: 2307: 2304: 2302: 2299: 2295: 2292: 2291: 2290: 2287: 2285: 2282: 2278: 2275: 2274: 2273: 2270: 2268: 2267:Arf invariant 2265: 2263: 2260: 2259: 2257: 2255: 2251: 2235: 2232: 2220: 2217: 2205: 2202: 2195: 2192: 2185: 2182: 2175: 2172: 2165: 2162: 2161: 2159: 2157: 2153: 2147: 2144: 2140: 2137: 2135: 2132: 2131: 2130: 2127: 2126: 2124: 2122: 2118: 2112: 2109: 2097: 2094: 2082: 2079: 2076: 2073: 2070: 2067: 2064: 2061: 2054: 2051: 2044: 2041: 2034: 2031: 2029: 2023: 2021: 2015: 2008: 2005: 1998: 1995: 1988: 1985: 1984: 1982: 1980: 1976: 1971: 1967: 1963: 1956: 1951: 1949: 1944: 1942: 1937: 1936: 1933: 1924: 1923: 1918: 1915: 1910: 1907: 1906: 1901: 1897: 1896: 1892: 1887: 1886: 1881: 1878: 1874: 1873: 1868: 1865: 1862: 1861: 1856: 1855:Marc Lackenby 1853: 1851: 1848: 1844: 1840: 1836: 1835:Marc Lackenby 1833: 1831: 1828: 1824: 1820: 1818: 1815: 1811: 1807: 1803: 1800: 1799: 1795: 1787: 1786: 1781: 1775: 1772: 1762:on 2020-07-27 1758: 1754: 1753: 1748: 1744: 1738: 1735: 1723:on 2006-02-09 1722: 1718: 1714: 1707: 1704: 1693: 1689: 1683: 1680: 1673: 1651: 1647: 1636: 1633: 1626: 1607: 1591: 1588: 1584: 1563: 1537: 1532: 1529: 1525: 1521: 1516: 1513: 1509: 1505: 1502: 1499: 1496: 1493: 1488: 1484: 1480: 1474: 1468: 1461: 1460: 1459: 1457: 1435: 1430: 1426: 1422: 1419: 1416: 1410: 1397: 1396: 1395: 1393: 1371: 1366: 1363: 1359: 1355: 1352: 1349: 1346: 1343: 1340: 1334: 1321: 1320: 1319: 1317: 1309: 1307: 1285: 1280: 1273: 1268: 1252: 1251:monodromy map 1248: 1235: 1231: 1225: 1221: 1215: 1211: 1210: 1207: 1205: 1201: 1197: 1193: 1189: 1184: 1182: 1178: 1174: 1150: 1145: 1128: 1125: 1119: 1115: 1111: 1102: 1094: 1089: 1087: 1084: 1080: 1076: 1072: 1069: 1066: 1062: 1058: 1054: 1050: 1046: 1038: 1018: 1007: 1003: 999: 996: 991: 987: 983: 980: 975: 971: 967: 964: 959: 955: 951: 945: 942: 937: 932: 929: 918: 910: 906: 902: 899: 894: 890: 886: 883: 878: 874: 870: 867: 862: 858: 854: 848: 845: 837: 833: 829: 824: 820: 816: 811: 807: 803: 798: 794: 787: 782: 774: 768: 765: 762: 759: 756: 753: 750: 744: 733: 732: 731: 712: 706: 703: 700: 697: 692: 688: 684: 679: 675: 671: 668: 665: 662: 656: 653: 647: 644: 641: 638: 635: 632: 629: 623: 616: 615: 614: 608: 600: 596: 592: 588: 580: 575: 573: 553: 550: 545: 543: 539: 535: 531: 527: 522: 520: 493: 490: 483: 480: 477: 475: 470: 459: 456: 449: 446: 442: 434: 431: 424: 421: 418: 415: 411: 407: 405: 400: 389: 386: 379: 376: 372: 364: 361: 354: 351: 348: 345: 341: 337: 335: 330: 319: 318: 317: 315: 311: 307: 299: 297: 295: 287: 285: 283: 279: 275: 271: 267: 264:(also called 263: 259: 250: 242: 238: 234: 230: 226: 222: 218: 213: 210: 203: 197: 195: 187: 183: 181: 177: 170: 168: 164: 161: 159: 155: 151: 149: 145: 141: 139: 135: 131: 129: 125: 121: 119: 115: 111: 109: 105: 101: 99: 95: 91: 89: 85: 81: 79: 75: 71: 69: 65: 61: 59: 58:Arf invariant 55: 52: 49: 45: 41: 36: 31: 26: 22: 2590: 2578: 2506:Double torus 2491:Braid theory 2306:Crossing no. 2301:Crosscap no. 1987:Figure-eight 1986: 1920: 1903: 1884: 1871: 1867:Robion Kirby 1859: 1838: 1822: 1805: 1783: 1774: 1764:, retrieved 1757:the original 1751: 1737: 1725:. Retrieved 1721:the original 1716: 1706: 1695:. Retrieved 1691: 1682: 1635: 1555: 1453: 1389: 1313: 1244: 1191: 1185: 1177:double-cover 1090: 1042: 729: 590: 586: 576: 552:closed braid 548: 547:(1) It is a 546: 542:fibered knot 523: 518: 516: 313: 309: 305: 303: 291: 278:trefoil knot 265: 261: 255: 167:A–B notation 108:Crossing no. 98:Crosscap no. 68:Braid length 2654:3-manifolds 2649:Twist knots 2614:Knot theory 2341:Linking no. 2262:Alternating 2063:Conway knot 2043:Carrick mat 1997:Three-twist 1962:Knot theory 1086:irreducible 1057:decomposing 1045:3-manifolds 595:John Milnor 549:homogeneous 530:alternating 300:Description 258:knot theory 221:alternating 47:Common name 2608:Categories 2501:Complement 2465:Tabulation 2422:operations 2346:Polynomial 2336:Link group 2331:Knot group 2294:Invertible 2272:Bridge no. 2254:Invariants 2184:Cinquefoil 2053:Perko pair 1979:Hyperbolic 1766:2020-10-19 1697:2020-06-25 1674:References 1310:Invariants 1141:(sequence 1129:2.02988... 1071:tetrahedra 1068:hyperbolic 1061:complement 1053:hyperbolic 599:Milnor map 282:prime knot 225:hyperbolic 184:4, 6, 8, 2 88:Bridge no. 2395:Stick no. 2351:Alexander 2289:Chirality 2234:Solomon's 2194:Septafoil 2121:Satellite 2081:Whitehead 2007:Stevedore 1922:MathWorld 1648:σ 1589:− 1530:− 1514:− 1506:− 1494:− 1423:− 1405:∇ 1364:− 1356:− 1344:− 1329:Δ 1159:Λ 1151:), where 1126:≈ 1112:π 1106:Λ 1063:into two 997:− 981:− 965:− 900:− 884:− 868:− 685:− 484:⁡ 450:⁡ 425:⁡ 380:⁡ 355:⁡ 138:Stick no. 78:Braid no. 2580:Category 2450:Mutation 2418:Notation 2371:Kauffman 2284:Brunnian 2277:2-bridge 2146:Knot sum 2077:(12n242) 1802:Ian Agol 1454:and the 1196:Lackenby 534:rational 316:) where 276:and the 25:Figure 8 2592:Commons 2511:Fibered 2409:problem 2378:Pretzel 2356:Bracket 2174:Trefoil 2111:L10a140 2071:(11n42) 2065:(11n34) 2033:Endless 1850:1756996 1830:1869847 1817:1799796 1179:of the 1171:is the 1147:in the 1144:A091518 538:achiral 229:fibered 204:/  132:2.02988 2556:Writhe 2526:Ribbon 2361:HOMFLY 2204:Unlink 2164:Unknot 2139:Square 2134:Granny 1541:  1439:  1375:  1093:volume 1081:, non- 927:  778:  730:where 597:) the 274:unknot 239:, 235:, 231:, 227:, 223:, 192:  190:Last / 2546:Twist 2531:Slice 2486:Berge 2474:Other 2445:Flype 2383:Prime 2366:Jones 2326:Genus 2156:Torus 1970:links 1966:knots 1760:(PDF) 1727:5 May 1627:Notes 1079:Haken 1065:ideal 1055:, by 526:prime 241:twist 233:prime 215:Other 118:Genus 2551:Wild 2516:Knot 2420:and 2407:and 2388:list 2219:Hopf 1968:and 1729:2022 1576:and 1390:the 1314:The 1202:and 1149:OEIS 1059:its 517:for 260:, a 194:Next 2536:Sum 2057:161 2055:(10 1902:", 1900:4_1 1782:", 1780:4_1 1458:is 1394:is 601:of 481:sin 447:sin 422:cos 377:cos 352:cos 256:In 2610:: 2236:(4 2221:(2 2206:(0 2196:(7 2186:(5 2176:(3 2166:(0 2098:(6 2083:(5 2047:18 2045:(8 2035:(7 2009:(6 1999:(5 1989:(4 1919:. 1869:, 1847:MR 1841:, 1837:, 1827:MR 1814:MR 1808:, 1804:, 1749:, 1715:. 1690:. 1306:. 1095:, 585:: 532:, 528:, 284:. 2245:) 2241:1 2230:) 2226:1 2215:) 2211:1 2200:) 2198:1 2190:) 2188:1 2180:) 2178:1 2170:) 2168:1 2107:) 2103:2 2092:) 2088:1 2059:) 2049:) 2039:) 2037:4 2027:3 2025:6 2019:2 2017:6 2013:) 2011:1 2003:) 2001:2 1993:) 1991:1 1972:) 1964:( 1954:e 1947:t 1940:v 1925:. 1898:" 1788:. 1778:" 1731:. 1700:. 1652:i 1592:1 1585:q 1564:q 1538:. 1533:2 1526:q 1522:+ 1517:1 1510:q 1503:1 1500:+ 1497:q 1489:2 1485:q 1481:= 1478:) 1475:q 1472:( 1469:V 1436:, 1431:2 1427:z 1420:1 1417:= 1414:) 1411:z 1408:( 1372:, 1367:1 1360:t 1353:3 1350:+ 1347:t 1341:= 1338:) 1335:t 1332:( 1294:) 1286:1 1281:1 1274:1 1269:2 1261:( 1123:) 1120:3 1116:/ 1109:( 1103:6 1019:. 1016:) 1013:) 1008:2 1004:t 1000:2 992:2 988:z 984:2 976:2 972:y 968:2 960:2 956:x 952:6 949:( 946:y 943:+ 938:2 933:x 930:t 919:, 916:) 911:2 907:t 903:2 895:2 891:z 887:2 879:2 875:y 871:2 863:2 859:x 855:6 852:( 849:x 846:+ 843:) 838:2 834:t 830:+ 825:2 821:z 817:+ 812:2 808:y 804:+ 799:2 795:x 791:( 788:z 785:( 775:= 772:) 769:t 766:, 763:z 760:, 757:y 754:, 751:x 748:( 745:G 713:, 710:) 707:t 704:z 701:2 698:, 693:2 689:t 680:2 676:z 672:, 669:y 666:, 663:x 660:( 657:G 654:= 651:) 648:t 645:, 642:z 639:, 636:y 633:, 630:x 627:( 624:F 611:F 603:F 591:R 589:→ 587:R 583:F 568:2 566:σ 564:1 562:σ 560:2 558:σ 556:1 519:t 497:) 494:t 491:4 488:( 478:= 471:z 463:) 460:t 457:3 454:( 443:) 438:) 435:t 432:2 429:( 419:+ 416:2 412:( 408:= 401:y 393:) 390:t 387:3 384:( 373:) 368:) 365:t 362:2 359:( 349:+ 346:2 342:( 338:= 331:x 314:z 312:, 310:y 308:, 306:x 208:1 206:5 201:1 199:3 173:1 171:4 152:1 142:7 122:1 112:4 102:2 92:2 82:3 72:4 62:1 27:.

Index

Figure-eight knot
Figure 8

Figure-eight knot
Arf invariant
Braid length
Braid no.
Bridge no.
Crosscap no.
Crossing no.
Genus
Hyperbolic volume
Stick no.
Unknotting no.
Conway notation
A–B notation
Dowker notation
Last / Next
31
51
alternating
hyperbolic
fibered
prime
fully amphichiral
twist

knot theory
crossing number
unknot

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