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Writhe

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A direction is assigned to the link at a point in each component and this direction is followed all the way around each component. For each crossing one comes across while traveling in this direction, if the strand underneath goes from right to left, the crossing is positive; if the lower strand goes
1544:{\displaystyle n_{1}={\frac {r_{13}\times r_{14}}{\left|r_{13}\times r_{14}\right|}},\;n_{2}={\frac {r_{14}\times r_{24}}{\left|r_{14}\times r_{24}\right|}},\;n_{3}={\frac {r_{24}\times r_{23}}{\left|r_{24}\times r_{23}\right|}},\;n_{4}={\frac {r_{23}\times r_{13}}{\left|r_{23}\times r_{13}\right|}}} 1947:
Any elastic rod, not just DNA, relieves torsional stress by coiling, an action which simultaneously untwists and bends the rod. F. Brock Fuller shows mathematically how the “elastic energy due to local twisting of the rod may be reduced if the central curve of the rod forms coils that increase its
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In addition, other methods to calculate writhe can be fully described mathematically and algorithmically, some of them outperform method above (which has quadratic computational complexity, by having linear complexity).
389: 668:{\displaystyle \operatorname {Wr} ={\frac {1}{4\pi }}\int _{C}\int _{C}d\mathbf {r} _{1}\times d\mathbf {r} _{2}\cdot {\frac {\mathbf {r} _{1}-\mathbf {r} _{2}}{\left|\mathbf {r} _{1}-\mathbf {r} _{2}\right|^{3}}}} 1787: 350: 708:
line segments. A procedure that was first derived by Michael Levitt for the description of protein folding and later used for supercoiled DNA by Konstantin Klenin and Jörg Langowski is to compute
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as values. In both cases, writhe is a geometric quantity, meaning that while deforming a curve (or diagram) in such a way that does not change its topology, one may still change its writhe.
1061: 1000: 234:(in the space curve sense) is equal to the average of the integral writhe values obtained from the projections from all vantage points. Hence, writhe in this situation can take on any 1748:{\displaystyle \Omega ^{*}=\arcsin \left(n_{1}\cdot n_{2}\right)+\arcsin \left(n_{2}\cdot n_{3}\right)+\arcsin \left(n_{3}\cdot n_{4}\right)+\arcsin \left(n_{4}\cdot n_{1}\right).} 1107: 914: 320: 296: 232: 45: 479: 450: 276: 204: 153:: moves of Type II and Type III do not affect the writhe. Reidemeister move Type I, however, increases or decreases the writhe by 1. This implies that the writhe of a knot is 1940:
to describe the amount a piece of DNA is deformed as a result of this torsional stress. In general, this phenomenon of forming coils due to writhe is referred to as
1177: 1779: 1217: 1197: 1147: 1127: 954: 934: 706: 499: 417: 2038: 862:{\displaystyle \operatorname {Wr} =\sum _{i=1}^{N}\sum _{j=1}^{N}{\frac {\Omega _{ij}}{4\pi }}=2\sum _{i=2}^{N}\sum _{j<i}{\frac {\Omega _{ij}}{4\pi }}} 130:
For a knot diagram, using the right-hand rule with either orientation gives the same result, so the writhe is well-defined on unoriented knot diagrams.
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of the knot itself — only the diagram. By a series of Type I moves one can set the writhe of a diagram for a given knot to be any integer at all.
362: 2386: 2356: 2017: 1898:{\displaystyle {\frac {\Omega }{4\pi }}={\frac {\Omega ^{*}}{4\pi }}{\text{sign}}\left(\left(r_{34}\times r_{12}\right)\cdot r_{13}\right).} 2954: 2873: 2420: 2245: 329: 2863: 2868: 2739: 2348: 1972: 323: 2440: 2174: 2502: 2340: 1936:
will coil when twisted, just like a rubber hose or a rope will, and that is why biomathematicians use the quantity of
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Writhe is also a property of a knot represented as a curve in three-dimensional space. Strictly speaking, a
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diagram. The writhe is the total number of positive crossings minus the total number of negative crossings.
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from left to right, the crossing is negative. One way of remembering this is to use a variation of the
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Klenin, Konstantin; Langowski, Jörg (2000). "Computation of writhe in modeling of supercoiled DNA".
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Levitt, Michael (1986). "Protein Folding by Restrained Energy Minimization and Molecular Dynamics".
2821: 2804: 2188: 2003: 2842: 2789: 2403: 2399: 2073: 2047: 170: 80: 56: 48: 688:, we can approximate its value numerically by first representing our curve as a finite chain of 2939: 2888: 2838: 2794: 2754: 2749: 2667: 2352: 2318: 2249: 2201: 2013: 150: 138: 2974: 2799: 2695: 2430: 2308: 2290: 2241: 2193: 2107: 2057: 1941: 1152: 207: 2304: 2158: 2121: 2069: 1761: 2934: 2898: 2833: 2779: 2734: 2727: 2617: 2529: 2412: 2300: 2154: 2117: 2065: 685: 174: 88: 173:
is such a curve, defined mathematically as an embedding of a circle in three-dimensional
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and is quite commonplace, and in fact in most organisms DNA is negatively supercoiled.
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values. In another sense, it is a quantity that describes the amount of "coiling" of a
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In a paper from 1959, Călugăreanu also showed how to calculate the writhe Wr with an
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Proceedings of the National Academy of Sciences of the United States of America
206:. By viewing the curve from different vantage points, one can obtain different 2979: 2964: 2919: 2816: 2769: 2764: 2759: 2589: 2486: 2061: 2345:
The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots
2112: 2095: 2984: 2652: 2253: 2139: 2096:"Sur les classes d'isotopie des nœuds tridimensionnels et leurs invariants" 680:
Numerically approximating the Gauss integral for writhe of a curve in space
384:{\displaystyle \operatorname {Wr} =\operatorname {Lk} -\operatorname {Tw} } 2322: 2295: 2205: 1924:
A simulation of an elastic rod relieving torsional stress by forming coils
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Finally, we compensate for the possible sign difference and divide by
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10.1002/1097-0282(20001015)54:5<307::aid-bip20>3.0.co;2-y
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is the exact evaluation of the double integral over line segments
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Cimasoni, David (2001). "Computing the writhe of a knot".
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The writhe of a knot is unaffected by two of the three
47:. In one sense, it is purely a property of an oriented 23:, there are several competing notions of the quantity 1790: 1764: 1563: 1228: 1205: 1185: 1155: 1135: 1115: 1072: 1008: 962: 942: 922: 879: 717: 694: 510: 487: 458: 429: 405: 365: 332: 308: 284: 255: 220: 183: 33: 2907: 2851: 2686: 2588: 2553: 2411: 1897: 1773: 1747: 1543: 1211: 1191: 1171: 1141: 1121: 1101: 1055: 994: 948: 928: 908: 861: 700: 684:Since writhe for a curve in space is defined as a 667: 493: 473: 444: 411: 383: 344: 314: 290: 270: 226: 198: 39: 501:. Then the writhe is equal to the Gauss integral 1056:{\displaystyle \Omega _{i,i+1}=\Omega _{ii}=0} 2380: 8: 2039:Journal of Knot Theory and Its Ramifications 2387: 2373: 2365: 1465: 1386: 1307: 79:, the writhe is a property of an oriented 2312: 2294: 2187: 2147:Revue de Mathématiques Pure et Appliquées 2111: 2051: 1881: 1863: 1850: 1831: 1815: 1809: 1791: 1789: 1763: 1731: 1718: 1689: 1676: 1647: 1634: 1605: 1592: 1568: 1562: 1528: 1515: 1499: 1486: 1479: 1470: 1449: 1436: 1420: 1407: 1400: 1391: 1370: 1357: 1341: 1328: 1321: 1312: 1291: 1278: 1262: 1249: 1242: 1233: 1227: 1204: 1184: 1160: 1154: 1134: 1114: 1091: 1086: 1077: 1071: 1038: 1013: 1007: 995:{\displaystyle \Omega _{ij}=\Omega _{ji}} 983: 967: 961: 941: 921: 898: 893: 884: 878: 840: 834: 822: 812: 801: 772: 766: 760: 749: 739: 728: 716: 693: 657: 646: 641: 631: 626: 612: 607: 597: 592: 588: 579: 574: 561: 556: 546: 536: 517: 509: 486: 465: 460: 457: 436: 431: 428: 404: 364: 331: 307: 283: 262: 258: 257: 254: 219: 190: 186: 185: 182: 63:) in three-dimensional space and assumes 32: 132: 1989: 2269:"The writhing number of a space curve" 1179:be the vector that begins at endpoint 352:depends only on the core curve of the 245:proved the following theorem: take a 7: 3020: 1102:{\displaystyle \Omega _{ij}/{4\pi }} 909:{\displaystyle \Omega _{ij}/{4\pi }} 1219:. Define the following quantities: 315:{\displaystyle \operatorname {Tw} } 291:{\displaystyle \operatorname {Lk} } 227:{\displaystyle \operatorname {Wr} } 40:{\displaystyle \operatorname {Wr} } 1812: 1793: 1565: 1074: 1035: 1010: 980: 964: 881: 837: 769: 302:of its border components, and let 14: 2100:Czechoslovak Mathematical Journal 3019: 3008: 3007: 642: 627: 608: 593: 575: 557: 474:{\displaystyle \mathbf {r} _{2}} 461: 445:{\displaystyle \mathbf {r} _{1}} 432: 271:{\displaystyle \mathbb {R} ^{3}} 199:{\displaystyle \mathbb {R} ^{3}} 106: 97: 2874:Dowker–Thistlethwaite notation 1: 2349:American Mathematical Society 2198:10.1016/s0022-2836(83)80129-6 2175:Journal of Molecular Biology 1929:Applications in DNA topology 1109:for given segments numbered 421:smooth, simple, closed curve 210:and draw the corresponding 103: 16:Invariant of a knot diagram 3064: 3003: 2864:Alexander–Briggs notation 2267:Fuller, F. Brock (1971). 2062:10.1142/S0218216501000913 2113:10.21136/CMJ.1961.100486 165:Writhe of a closed curve 2955:List of knots and links 2503:Kinoshita–Terasaka knot 2010:Oxford University Press 71:Writhe of link diagrams 2002:Bates, Andrew (2005). 1925: 1899: 1775: 1749: 1545: 1213: 1193: 1173: 1172:{\displaystyle r_{pq}} 1143: 1123: 1103: 1057: 996: 950: 930: 910: 863: 817: 765: 744: 702: 669: 495: 475: 446: 413: 385: 346: 326:. Then the difference 316: 292: 272: 241:In a paper from 1961, 228: 200: 146: 41: 2745:Finite type invariant 2296:10.1073/pnas.68.4.815 2136:Călugăreanu, Gheorghe 2092:Călugăreanu, Gheorghe 1923: 1900: 1776: 1774:{\displaystyle 4\pi } 1750: 1546: 1214: 1199:and ends at endpoint 1194: 1174: 1144: 1124: 1104: 1058: 997: 951: 931: 911: 864: 797: 745: 724: 703: 670: 496: 476: 447: 414: 386: 347: 317: 293: 273: 238:as a possible value. 229: 201: 136: 42: 1788: 1762: 1561: 1226: 1203: 1183: 1153: 1133: 1113: 1070: 1006: 960: 940: 920: 877: 715: 692: 508: 485: 456: 427: 403: 363: 330: 306: 282: 253: 243:Gheorghe Călugăreanu 218: 181: 51:diagram and assumes 31: 2915:Alexander's theorem 2287:1971PNAS...68..815B 1973:Twist (mathematics) 61:closed simple curve 2012:. pp. 36–37. 1948:writhing number”. 1926: 1895: 1771: 1745: 1554:Then we calculate 1541: 1209: 1189: 1169: 1139: 1119: 1099: 1053: 992: 946: 926: 906: 859: 833: 698: 665: 491: 471: 442: 409: 381: 342: 312: 288: 268: 224: 196: 151:Reidemeister moves 147: 37: 3035: 3034: 2889:Reidemeister move 2755:Khovanov homology 2750:Hyperbolic volume 2358:978-0-8218-3678-1 2019:978-0-19-850655-3 1921: 1834: 1829: 1804: 1539: 1460: 1381: 1302: 1212:{\displaystyle q} 1192:{\displaystyle p} 1142:{\displaystyle j} 1122:{\displaystyle i} 949:{\displaystyle j} 929:{\displaystyle i} 857: 818: 789: 701:{\displaystyle N} 663: 530: 494:{\displaystyle C} 412:{\displaystyle C} 159:isotopy invariant 139:Reidemeister move 128: 127: 57:mathematical knot 3055: 3023: 3022: 3011: 3010: 2975:Tait conjectures 2678: 2677: 2663: 2662: 2648: 2647: 2540: 2539: 2525: 2524: 2509:(−2,3,7) pretzel 2389: 2382: 2375: 2366: 2361: 2327: 2326: 2316: 2298: 2264: 2258: 2257: 2227: 2210: 2209: 2191: 2169: 2163: 2162: 2144: 2132: 2126: 2125: 2115: 2088: 2082: 2081: 2055: 2046:(387): 387–395. 2033: 2024: 2023: 1999: 1958:DNA supercoiling 1942:DNA supercoiling 1922: 1904: 1902: 1901: 1896: 1891: 1887: 1886: 1885: 1873: 1869: 1868: 1867: 1855: 1854: 1835: 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865: 860: 858: 856: 848: 847: 835: 832: 816: 811: 790: 788: 780: 779: 767: 764: 759: 743: 738: 707: 705: 704: 699: 674: 672: 671: 666: 664: 662: 661: 656: 652: 651: 650: 645: 636: 635: 630: 618: 617: 616: 611: 602: 601: 596: 589: 584: 583: 578: 566: 565: 560: 551: 550: 541: 540: 531: 529: 518: 500: 498: 497: 492: 480: 478: 477: 472: 470: 469: 464: 451: 449: 448: 443: 441: 440: 435: 418: 416: 415: 410: 390: 388: 387: 382: 351: 349: 348: 343: 321: 319: 318: 313: 297: 295: 294: 289: 277: 275: 274: 269: 267: 266: 261: 233: 231: 230: 225: 205: 203: 202: 197: 195: 194: 189: 110: 101: 94: 93: 46: 44: 43: 38: 3063: 3062: 3058: 3057: 3056: 3054: 3053: 3052: 3038: 3037: 3036: 3031: 2999: 2903: 2869:Conway notation 2853: 2847: 2834:Tricolorability 2682: 2676: 2673: 2672: 2671: 2661: 2658: 2657: 2656: 2646: 2643: 2642: 2641: 2633: 2623: 2613: 2603: 2584: 2563:Composite knots 2549: 2538: 2535: 2534: 2533: 2530:Borromean rings 2523: 2520: 2519: 2518: 2492: 2482: 2472: 2462: 2454: 2446: 2436: 2426: 2407: 2393: 2359: 2339: 2336: 2334:Further reading 2331: 2330: 2266: 2265: 2261: 2229: 2228: 2213: 2171: 2170: 2166: 2142: 2134: 2133: 2129: 2090: 2089: 2085: 2035: 2034: 2027: 2020: 2001: 2000: 1991: 1986: 1954: 1931: 1912: 1877: 1859: 1846: 1845: 1841: 1840: 1836: 1821: 1811: 1796: 1786: 1785: 1760: 1759: 1727: 1714: 1713: 1709: 1685: 1672: 1671: 1667: 1643: 1630: 1629: 1625: 1601: 1588: 1587: 1583: 1564: 1559: 1558: 1524: 1511: 1510: 1506: 1495: 1482: 1481: 1466: 1445: 1432: 1431: 1427: 1416: 1403: 1402: 1387: 1366: 1353: 1352: 1348: 1337: 1324: 1323: 1308: 1287: 1274: 1273: 1269: 1258: 1245: 1244: 1229: 1224: 1223: 1201: 1200: 1181: 1180: 1156: 1151: 1150: 1131: 1130: 1111: 1110: 1073: 1068: 1067: 1034: 1009: 1004: 1003: 979: 963: 958: 957: 938: 937: 918: 917: 880: 875: 874: 849: 836: 781: 768: 713: 712: 690: 689: 686:double integral 682: 640: 625: 624: 620: 619: 606: 591: 590: 573: 555: 542: 532: 522: 506: 505: 483: 482: 459: 454: 453: 430: 425: 424: 401: 400: 361: 360: 328: 327: 304: 303: 280: 279: 256: 251: 250: 216: 215: 184: 179: 178: 175:Euclidean space 167: 123: 116: 89:right-hand rule 73: 29: 28: 17: 12: 11: 5: 3061: 3059: 3051: 3050: 3040: 3039: 3033: 3032: 3030: 3029: 3017: 3004: 3001: 3000: 2998: 2997: 2995:Surgery theory 2992: 2987: 2982: 2977: 2972: 2967: 2962: 2957: 2952: 2947: 2942: 2937: 2932: 2927: 2922: 2917: 2911: 2909: 2905: 2904: 2902: 2901: 2896: 2894:Skein relation 2891: 2886: 2881: 2876: 2871: 2866: 2860: 2858: 2849: 2848: 2846: 2845: 2839:Unknotting no. 2836: 2831: 2826: 2825: 2824: 2814: 2809: 2808: 2807: 2802: 2797: 2792: 2787: 2777: 2772: 2767: 2762: 2757: 2752: 2747: 2742: 2737: 2732: 2731: 2730: 2720: 2715: 2714: 2713: 2703: 2698: 2692: 2690: 2684: 2683: 2681: 2680: 2674: 2665: 2659: 2650: 2644: 2635: 2631: 2625: 2621: 2615: 2611: 2605: 2601: 2594: 2592: 2586: 2585: 2583: 2582: 2577: 2576: 2575: 2570: 2559: 2557: 2551: 2550: 2548: 2547: 2542: 2536: 2527: 2521: 2512: 2506: 2500: 2494: 2490: 2484: 2480: 2474: 2470: 2464: 2460: 2456: 2452: 2448: 2444: 2438: 2434: 2428: 2424: 2417: 2415: 2409: 2408: 2394: 2392: 2391: 2384: 2377: 2369: 2363: 2362: 2357: 2335: 2332: 2329: 2328: 2281:(4): 815–819. 2259: 2240:(5): 307–317. 2211: 2189:10.1.1.26.3656 2182:(3): 723–764. 2164: 2127: 2106:(4): 588–625. 2083: 2025: 2018: 1988: 1987: 1985: 1982: 1981: 1980: 1978:Winding number 1975: 1970: 1965: 1963:Linking number 1960: 1953: 1950: 1930: 1927: 1906: 1905: 1894: 1890: 1884: 1880: 1876: 1872: 1866: 1862: 1858: 1853: 1849: 1844: 1839: 1827: 1824: 1818: 1814: 1808: 1802: 1799: 1795: 1770: 1767: 1756: 1755: 1744: 1740: 1734: 1730: 1726: 1721: 1717: 1712: 1708: 1705: 1702: 1698: 1692: 1688: 1684: 1679: 1675: 1670: 1666: 1663: 1660: 1656: 1650: 1646: 1642: 1637: 1633: 1628: 1624: 1621: 1618: 1614: 1608: 1604: 1600: 1595: 1591: 1586: 1582: 1579: 1576: 1571: 1567: 1552: 1551: 1537: 1531: 1527: 1523: 1518: 1514: 1509: 1502: 1498: 1494: 1489: 1485: 1478: 1473: 1469: 1464: 1458: 1452: 1448: 1444: 1439: 1435: 1430: 1423: 1419: 1415: 1410: 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9: 6: 4: 3: 2: 3060: 3049: 3046: 3045: 3043: 3028: 3027: 3018: 3016: 3015: 3006: 3005: 3002: 2996: 2993: 2991: 2988: 2986: 2983: 2981: 2978: 2976: 2973: 2971: 2968: 2966: 2963: 2961: 2958: 2956: 2953: 2951: 2948: 2946: 2943: 2941: 2938: 2936: 2933: 2931: 2930:Conway sphere 2928: 2926: 2923: 2921: 2918: 2916: 2913: 2912: 2910: 2906: 2900: 2897: 2895: 2892: 2890: 2887: 2885: 2882: 2880: 2877: 2875: 2872: 2870: 2867: 2865: 2862: 2861: 2859: 2857: 2850: 2844: 2840: 2837: 2835: 2832: 2830: 2827: 2823: 2820: 2819: 2818: 2815: 2813: 2810: 2806: 2803: 2801: 2798: 2796: 2793: 2791: 2788: 2786: 2783: 2782: 2781: 2778: 2776: 2773: 2771: 2768: 2766: 2763: 2761: 2758: 2756: 2753: 2751: 2748: 2746: 2743: 2741: 2738: 2736: 2733: 2729: 2726: 2725: 2724: 2721: 2719: 2716: 2712: 2709: 2708: 2707: 2704: 2702: 2701:Arf invariant 2699: 2697: 2694: 2693: 2691: 2689: 2685: 2669: 2666: 2654: 2651: 2639: 2636: 2629: 2626: 2619: 2616: 2609: 2606: 2599: 2596: 2595: 2593: 2591: 2587: 2581: 2578: 2574: 2571: 2569: 2566: 2565: 2564: 2561: 2560: 2558: 2556: 2552: 2546: 2543: 2531: 2528: 2516: 2513: 2510: 2507: 2504: 2501: 2498: 2495: 2488: 2485: 2478: 2475: 2468: 2465: 2463: 2457: 2455: 2449: 2442: 2439: 2432: 2429: 2422: 2419: 2418: 2416: 2414: 2410: 2405: 2401: 2397: 2390: 2385: 2383: 2378: 2376: 2371: 2370: 2367: 2360: 2354: 2350: 2346: 2342: 2338: 2337: 2333: 2324: 2320: 2315: 2310: 2306: 2302: 2297: 2292: 2288: 2284: 2280: 2276: 2275: 2270: 2263: 2260: 2255: 2251: 2247: 2243: 2239: 2235: 2234: 2226: 2224: 2222: 2220: 2218: 2216: 2212: 2207: 2203: 2199: 2195: 2190: 2185: 2181: 2177: 2176: 2168: 2165: 2160: 2156: 2152: 2149:(in French). 2148: 2141: 2137: 2131: 2128: 2123: 2119: 2114: 2109: 2105: 2102:(in French). 2101: 2097: 2093: 2087: 2084: 2079: 2075: 2071: 2067: 2063: 2059: 2054: 2049: 2045: 2041: 2040: 2032: 2030: 2026: 2021: 2015: 2011: 2007: 2006: 1998: 1996: 1994: 1990: 1983: 1979: 1976: 1974: 1971: 1969: 1968:Ribbon theory 1966: 1964: 1961: 1959: 1956: 1955: 1951: 1949: 1945: 1943: 1939: 1935: 1928: 1910: 1892: 1888: 1882: 1878: 1874: 1870: 1864: 1860: 1856: 1851: 1847: 1842: 1837: 1825: 1822: 1816: 1806: 1800: 1797: 1784: 1783: 1782: 1768: 1765: 1742: 1738: 1732: 1728: 1724: 1719: 1715: 1710: 1706: 1703: 1700: 1696: 1690: 1686: 1682: 1677: 1673: 1668: 1664: 1661: 1658: 1654: 1648: 1644: 1640: 1635: 1631: 1626: 1622: 1619: 1616: 1612: 1606: 1602: 1598: 1593: 1589: 1584: 1580: 1577: 1574: 1569: 1557: 1556: 1555: 1535: 1529: 1525: 1521: 1516: 1512: 1507: 1500: 1496: 1492: 1487: 1483: 1476: 1471: 1467: 1462: 1456: 1450: 1446: 1442: 1437: 1433: 1428: 1421: 1417: 1413: 1408: 1404: 1397: 1392: 1388: 1383: 1377: 1371: 1367: 1363: 1358: 1354: 1349: 1342: 1338: 1334: 1329: 1325: 1318: 1313: 1309: 1304: 1298: 1292: 1288: 1284: 1279: 1275: 1270: 1263: 1259: 1255: 1250: 1246: 1239: 1234: 1230: 1222: 1221: 1220: 1206: 1186: 1164: 1161: 1157: 1136: 1116: 1095: 1092: 1087: 1081: 1078: 1064: 1050: 1047: 1042: 1039: 1031: 1026: 1023: 1020: 1017: 1014: 987: 984: 976: 971: 968: 943: 923: 902: 899: 894: 888: 885: 853: 850: 844: 841: 829: 826: 823: 819: 813: 808: 805: 802: 798: 794: 791: 785: 782: 776: 773: 761: 756: 753: 750: 746: 740: 735: 732: 729: 725: 721: 718: 711: 710: 709: 695: 687: 679: 658: 653: 647: 637: 632: 621: 613: 603: 598: 585: 580: 570: 567: 562: 552: 547: 543: 537: 533: 526: 523: 519: 514: 511: 504: 503: 502: 488: 481:be points on 466: 437: 422: 406: 398: 378: 375: 372: 369: 366: 359: 358: 357: 355: 339: 336: 333: 325: 322:be its total 309: 301: 285: 263: 248: 244: 239: 237: 221: 214:. Its writhe 213: 212:knot diagrams 209: 191: 176: 172: 164: 162: 160: 156: 152: 144: 140: 135: 131: 121: 119: 114: 113: 109: 105: 100: 96: 95: 92: 90: 84: 82: 78: 70: 68: 66: 62: 58: 54: 50: 34: 26: 22: 3024: 3012: 2989: 2940:Double torus 2925:Braid theory 2740:Crossing no. 2735:Crosscap no. 2421:Figure-eight 2344: 2341:Adams, Colin 2278: 2272: 2262: 2237: 2231: 2179: 2173: 2167: 2150: 2146: 2130: 2103: 2099: 2086: 2053:math/0406148 2043: 2037: 2005:DNA Topology 2004: 1946: 1937: 1932: 1907: 1757: 1553: 1066:To evaluate 1065: 956:; note that 872: 683: 394: 240: 168: 154: 148: 142: 141:changes the 129: 85: 74: 65:real numbers 24: 18: 3048:Knot theory 2775:Linking no. 2696:Alternating 2497:Conway knot 2477:Carrick mat 2431:Three-twist 2396:Knot theory 2233:Biopolymers 236:real number 208:projections 77:knot theory 21:knot theory 2935:Complement 2899:Tabulation 2856:operations 2780:Polynomial 2770:Link group 2765:Knot group 2728:Invertible 2706:Bridge no. 2688:Invariants 2618:Cinquefoil 2487:Perko pair 2413:Hyperbolic 1984:References 1781:to obtain 2829:Stick no. 2785:Alexander 2723:Chirality 2668:Solomon's 2628:Septafoil 2555:Satellite 2515:Whitehead 2441:Stevedore 2184:CiteSeerX 1875:⋅ 1857:× 1826:π 1817:∗ 1813:Ω 1801:π 1794:Ω 1769:π 1725:⋅ 1707:⁡ 1683:⋅ 1665:⁡ 1641:⋅ 1623:⁡ 1599:⋅ 1581:⁡ 1570:∗ 1566:Ω 1522:× 1493:× 1443:× 1414:× 1364:× 1335:× 1285:× 1256:× 1096:π 1075:Ω 1036:Ω 1011:Ω 981:Ω 965:Ω 903:π 882:Ω 854:π 838:Ω 820:∑ 799:∑ 786:π 770:Ω 747:∑ 726:∑ 638:− 604:− 586:⋅ 568:× 544:∫ 534:∫ 527:π 376:− 337:− 137:A Type I 124:crossing 3042:Category 3014:Category 2884:Mutation 2852:Notation 2805:Kauffman 2718:Brunnian 2711:2-bridge 2580:Knot sum 2511:(12n242) 2343:(2004), 2254:10935971 2153:: 5–20. 2138:(1959). 2094:(1961). 2078:15850269 1952:See also 423:and let 397:integral 122:Negative 117:crossing 115:Positive 59:(or any 3026:Commons 2945:Fibered 2843:problem 2812:Pretzel 2790:Bracket 2608:Trefoil 2545:L10a140 2505:(11n42) 2499:(11n34) 2467:Endless 2323:5279522 2305:0278197 2283:Bibcode 2206:6195346 2159:0131846 2122:0149378 2070:1825964 298:be the 53:integer 2990:Writhe 2960:Ribbon 2795:HOMFLY 2638:Unlink 2598:Unknot 2573:Square 2568:Granny 2355:  2321:  2314:389050 2311:  2303:  2252:  2204:  2186:  2157:  2120:  2076:  2068:  2016:  1938:writhe 1704:arcsin 1662:arcsin 1620:arcsin 1578:arcsin 873:where 399:. Let 356:, and 354:ribbon 278:, let 247:ribbon 143:writhe 25:writhe 2980:Twist 2965:Slice 2920:Berge 2908:Other 2879:Flype 2817:Prime 2800:Jones 2760:Genus 2590:Torus 2404:links 2400:knots 2143:(PDF) 2074:S2CID 2048:arXiv 419:be a 324:twist 27:, or 2985:Wild 2950:Knot 2854:and 2841:and 2822:list 2653:Hopf 2402:and 2353:ISBN 2319:PMID 2250:PMID 2202:PMID 2014:ISBN 1833:sign 1129:and 1002:and 936:and 827:< 452:and 171:knot 145:by 1 81:link 49:link 2970:Sum 2491:161 2489:(10 2309:PMC 2291:doi 2242:doi 2194:doi 2180:170 2108:doi 2058:doi 1934:DNA 249:in 157:an 155:not 75:In 19:In 3044:: 2670:(4 2655:(2 2640:(0 2630:(7 2620:(5 2610:(3 2600:(0 2532:(6 2517:(5 2481:18 2479:(8 2469:(7 2443:(6 2433:(5 2423:(4 2351:, 2347:, 2317:. 2307:. 2301:MR 2299:. 2289:. 2279:68 2277:. 2271:. 2248:. 2238:54 2236:. 2214:^ 2200:. 2192:. 2178:. 2155:MR 2145:. 2118:MR 2116:. 2104:11 2098:. 2072:. 2066:MR 2064:. 2056:. 2044:10 2042:. 2028:^ 2008:. 1992:^ 1883:13 1865:12 1852:34 1530:13 1517:23 1501:13 1488:23 1451:23 1438:24 1422:23 1409:24 1372:24 1359:14 1343:24 1330:14 1293:14 1280:13 1264:14 1251:13 1063:. 719:Wr 512:Wr 379:Tw 373:Lk 367:Wr 340:Tw 334:Lk 310:Tw 286:Lk 222:Wr 177:, 91:. 35:Wr 2679:) 2675:1 2664:) 2660:1 2649:) 2645:1 2634:) 2632:1 2624:) 2622:1 2614:) 2612:1 2604:) 2602:1 2541:) 2537:2 2526:) 2522:1 2493:) 2483:) 2473:) 2471:4 2461:3 2459:6 2453:2 2451:6 2447:) 2445:1 2437:) 2435:2 2427:) 2425:1 2406:) 2398:( 2388:e 2381:t 2374:v 2325:. 2293:: 2285:: 2256:. 2244:: 2208:. 2196:: 2161:. 2151:4 2124:. 2110:: 2080:. 2060:: 2050:: 2022:. 1893:. 1889:) 1879:r 1871:) 1861:r 1848:r 1843:( 1838:( 1823:4 1807:= 1798:4 1766:4 1743:. 1739:) 1733:1 1729:n 1720:4 1716:n 1711:( 1701:+ 1697:) 1691:4 1687:n 1678:3 1674:n 1669:( 1659:+ 1655:) 1649:3 1645:n 1636:2 1632:n 1627:( 1617:+ 1613:) 1607:2 1603:n 1594:1 1590:n 1585:( 1575:= 1536:| 1526:r 1513:r 1508:| 1497:r 1484:r 1477:= 1472:4 1468:n 1463:, 1457:| 1447:r 1434:r 1429:| 1418:r 1405:r 1398:= 1393:3 1389:n 1384:, 1378:| 1368:r 1355:r 1350:| 1339:r 1326:r 1319:= 1314:2 1310:n 1305:, 1299:| 1289:r 1276:r 1271:| 1260:r 1247:r 1240:= 1235:1 1231:n 1207:q 1187:p 1165:q 1162:p 1158:r 1137:j 1117:i 1093:4 1088:/ 1082:j 1079:i 1051:0 1048:= 1043:i 1040:i 1032:= 1027:1 1024:+ 1021:i 1018:, 1015:i 988:i 985:j 977:= 972:j 969:i 944:j 924:i 900:4 895:/ 889:j 886:i 869:, 851:4 845:j 842:i 830:i 824:j 814:N 809:2 806:= 803:i 795:2 792:= 783:4 777:j 774:i 762:N 757:1 754:= 751:j 741:N 736:1 733:= 730:i 722:= 696:N 675:. 659:3 654:| 648:2 643:r 633:1 628:r 622:| 614:2 609:r 599:1 594:r 581:2 576:r 571:d 563:1 558:r 553:d 548:C 538:C 524:4 520:1 515:= 489:C 467:2 462:r 438:1 433:r 407:C 391:. 370:= 264:3 259:R 192:3 187:R

Index

knot theory
link
integer
mathematical knot
closed simple curve
real numbers
knot theory
link
right-hand rule



Reidemeister move
Reidemeister moves
isotopy invariant
knot
Euclidean space
projections
knot diagrams
real number
Gheorghe Călugăreanu
ribbon
linking number
twist
ribbon
integral
smooth, simple, closed curve
double integral
DNA
DNA supercoiling

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