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Knot thickness

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124: 223: 32:. Each realization of a link or knot has a thickness assigned to it. The thickness τ of a link allows us to introduce a scale with respect to which we can then define the 258:"O. Gonzalez, J.H. Maddocks, "Global Curvature, Thickness and the Ideal Shapes of Knots", Proc. National Academy of Sciences of the USA 96 (1999) 4769–4773" 257: 169:). From this definition we can deduce that the local thickness is at most equal to the local radius of curvature. 66: 178: 314: 25: 21: 241:) will not self intersect, and so we arrive at a "real world" knot made out of a thick string. 44:
There exist several possible definitions of thickness that coincide for smooth enough curves.
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Litherland, R. A.; Simon, J.; Durumeric, O.; Rawdon, E. (1999-02-24). "Thickness of knots".
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The thickness is defined using the simpler concept of the local thickness τ(
157:) is the radius of the circle that passes through all three points ( 181: 69: 217: 118: 197: 85: 8: 141:are points on the link, all distinct, and 180: 119:{\displaystyle \tau (x)=\inf r(x,y,z),\,} 115: 68: 249: 218:{\displaystyle \tau (L)=\inf \tau (x).} 172:The thickness of a link is defined as 7: 237:to the link with radius equal to τ( 56:). The local thickness at a point 14: 233:This definition ensures that a 209: 203: 191: 185: 109: 91: 79: 73: 1: 296:10.1016/S0166-8641(97)00210-1 284:Topology and Its Applications 331: 60:on the link is defined as 48:Global radius of curvature 219: 120: 220: 121: 28:can have an assigned 179: 67: 229:Injectivity radius 215: 116: 322: 300: 299: 279: 273: 272: 270: 269: 260:. Archived from 254: 224: 222: 221: 216: 125: 123: 122: 117: 330: 329: 325: 324: 323: 321: 320: 319: 305: 304: 303: 281: 280: 276: 267: 265: 256: 255: 251: 247: 231: 177: 176: 65: 64: 50: 42: 12: 11: 5: 328: 326: 318: 317: 307: 306: 302: 301: 290:(3): 233–244. 274: 248: 246: 243: 230: 227: 226: 225: 214: 211: 208: 205: 202: 199: 196: 193: 190: 187: 184: 127: 126: 114: 111: 108: 105: 102: 99: 96: 93: 90: 87: 84: 81: 78: 75: 72: 49: 46: 41: 38: 30:knot thickness 13: 10: 9: 6: 4: 3: 2: 327: 316: 313: 312: 310: 297: 293: 289: 285: 278: 275: 264:on 2011-07-06 263: 259: 253: 250: 244: 242: 240: 236: 228: 212: 206: 200: 194: 188: 182: 175: 174: 173: 170: 168: 164: 160: 156: 152: 148: 144: 140: 136: 132: 112: 106: 103: 100: 97: 94: 88: 82: 76: 70: 63: 62: 61: 59: 55: 47: 45: 39: 37: 35: 31: 27: 23: 19: 287: 283: 277: 266:. Retrieved 262:the original 252: 238: 232: 171: 166: 162: 158: 154: 150: 146: 142: 138: 134: 130: 128: 57: 53: 51: 43: 29: 15: 315:Knot theory 235:normal tube 36:of a link. 18:knot theory 268:2009-05-08 245:References 40:Definition 34:ropelength 201:τ 183:τ 71:τ 309:Category 165:,  161:,  153:,  149:,  20:, each 137:, and 129:where 26:knot 24:and 22:link 292:doi 198:inf 86:inf 16:In 311:: 288:91 286:. 133:, 298:. 294:: 271:. 239:L 213:. 210:) 207:x 204:( 195:= 192:) 189:L 186:( 167:z 163:y 159:x 155:z 151:y 147:x 145:( 143:r 139:z 135:y 131:x 113:, 110:) 107:z 104:, 101:y 98:, 95:x 92:( 89:r 83:= 80:) 77:x 74:( 58:x 54:x

Index

knot theory
link
knot
ropelength
normal tube
"O. Gonzalez, J.H. Maddocks, "Global Curvature, Thickness and the Ideal Shapes of Knots", Proc. National Academy of Sciences of the USA 96 (1999) 4769–4773"
the original
doi
10.1016/S0166-8641(97)00210-1
Category
Knot theory

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