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Packing density

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of upper densities obtained by packings that are subcollections of the supply collection. If the supply collection consists of convex bodies of bounded diameter, there exists a packing whose packing density is equal to the packing constant, and this packing constant does not vary if the balls in the
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of the above respectively. If the density exists, the upper and lower densities are equal. Provided that any ball of the Euclidean space intersects only finitely many elements of the packing and that the diameters of the elements are bounded from above, the (upper, lower) density does not depend on
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One is often interested in packings restricted to use elements of a certain supply collection. For example, the supply collection may be the set of all balls of a given radius. The
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of the space filled by the figures making up the packing. In simplest terms, this is the ratio of the volume of bodies in a space to the volume of the space itself. In
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of a fixed body is also a common supply collection of interest, and it defines the translative packing constant of that body.
415:. The ball may also be replaced by dilations of some other convex body, but in general the resulting densities are not equal. 359: 176:, it is customary to define the density as the limit of densities exhibited in balls of larger and larger radii. If 460: 347:{\displaystyle \eta =\lim _{t\to \infty }{\frac {\sum _{i=1}^{\infty }\mu (K_{i}\cap B_{t})}{\mu (B_{t})}}} 358:
Since this limit does not always exist, it is also useful to define the upper and lower densities as the
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and their interiors pairwise do not intersect, then the collection is a packing in
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Groemer, H. (1986), "Some basic properties of packing and covering constants",
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states that 3-balls have the lowest packing constant of any convex solid. All
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definition of density are replaced by dilations of some other convex body.
523: 550: 449:. In this case, we call the packing constant the packing constant of 432: 156:{\displaystyle \eta ={\frac {\sum _{i=1}^{n}\mu (K_{i})}{\mu (X)}}} 16:
Fraction of a space filled by objects packed into that space
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If the space being packed is infinite in measure, such as
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centered at the origin, then the density of a packing
241: 214: 86: 459:is concerned with the packing constant of 3-balls. 439:A particular supply collection of interest is all 346: 222: 155: 561: 249: 504: 502: 431:associated with a supply collection is the 499: 487:List of shapes with known packing constant 418: 522: 216: 508: 562: 541: 167: 38: 511:Discrete and Computational Geometry 13: 404:for every element that intersects 283: 259: 27:of a packing in some space is the 14: 586: 534: 360:limit superior and limit inferior 338: 325: 317: 291: 256: 147: 141: 133: 120: 1: 492: 223:{\displaystyle \mathbb {N} } 59:are measurable subsets of a 7: 470: 77:and its packing density is 10: 591: 363:the choice of origin, and 461:Ulam's packing conjecture 443:of a fixed convex body 425:optimal packing density 419:Optimal packing density 348: 287: 224: 187:is the ball of radius 157: 116: 477:Atomic packing factor 349: 267: 225: 158: 96: 239: 212: 84: 388:can be replaced by 543:Weisstein, Eric W. 524:10.1007/BF02187693 344: 263: 220: 168:In Euclidean space 153: 575:Discrete geometry 546:"Packing Density" 457:Kepler conjecture 441:Euclidean motions 342: 248: 151: 39:In compact spaces 582: 570:Packing problems 556: 555: 528: 527: 526: 506: 454: 448: 429:packing constant 414: 403: 387: 353: 351: 350: 345: 343: 341: 337: 336: 320: 316: 315: 303: 302: 286: 281: 265: 262: 231: 229: 227: 226: 221: 219: 192: 186: 162: 160: 159: 154: 152: 150: 136: 132: 131: 115: 110: 94: 76: 70: 58: 33:packing problems 25:packing fraction 590: 589: 585: 584: 583: 581: 580: 579: 560: 559: 537: 532: 531: 507: 500: 495: 473: 450: 444: 421: 413: 405: 401: 389: 385: 376: 364: 332: 328: 321: 311: 307: 298: 294: 282: 271: 266: 264: 252: 240: 237: 236: 215: 213: 210: 209: 203: 194: 188: 185: 177: 174:Euclidean space 170: 137: 127: 123: 111: 100: 95: 93: 85: 82: 81: 72: 66: 57: 50: 44: 41: 21:packing density 17: 12: 11: 5: 588: 578: 577: 572: 558: 557: 536: 535:External links 533: 530: 529: 517:(2): 183–193, 497: 496: 494: 491: 490: 489: 484: 482:Sphere packing 479: 472: 469: 420: 417: 409: 397: 381: 372: 356: 355: 340: 335: 331: 327: 324: 319: 314: 310: 306: 301: 297: 293: 290: 285: 280: 277: 274: 270: 261: 258: 255: 251: 247: 244: 218: 199: 181: 169: 166: 165: 164: 149: 146: 143: 140: 135: 130: 126: 122: 119: 114: 109: 106: 103: 99: 92: 89: 55: 48: 40: 37: 15: 9: 6: 4: 3: 2: 587: 576: 573: 571: 568: 567: 565: 553: 552: 547: 544: 539: 538: 525: 520: 516: 512: 505: 503: 498: 488: 485: 483: 480: 478: 475: 474: 468: 466: 462: 458: 453: 447: 442: 437: 434: 430: 426: 416: 412: 408: 400: 396: 392: 384: 380: 375: 371: 367: 361: 333: 329: 322: 312: 308: 304: 299: 295: 288: 278: 275: 272: 268: 253: 245: 242: 235: 234: 233: 207: 202: 198: 191: 184: 180: 175: 144: 138: 128: 124: 117: 112: 107: 104: 101: 97: 90: 87: 80: 79: 78: 75: 69: 65: 64:measure space 62: 54: 47: 36: 34: 30: 26: 22: 549: 514: 510: 465:translations 451: 445: 438: 428: 424: 422: 410: 406: 398: 394: 390: 382: 378: 373: 369: 365: 357: 205: 200: 196: 189: 182: 178: 171: 73: 67: 52: 45: 42: 24: 20: 18: 564:Categories 493:References 551:MathWorld 323:μ 305:∩ 289:μ 284:∞ 269:∑ 260:∞ 257:→ 243:η 139:μ 118:μ 98:∑ 88:η 471:See also 433:supremum 204: : 29:fraction 61:compact 455:. The 51:,..., 519:doi 427:or 250:lim 232:is 43:If 23:or 566:: 548:. 513:, 501:^ 19:A 554:. 521:: 515:1 452:K 446:K 411:t 407:B 402:) 399:i 395:K 393:( 391:μ 386:) 383:t 379:B 377:∩ 374:i 370:K 368:( 366:μ 354:. 339:) 334:t 330:B 326:( 318:) 313:t 309:B 300:i 296:K 292:( 279:1 276:= 273:i 254:t 246:= 230:] 217:N 208:∈ 206:i 201:i 197:K 195:[ 190:t 183:t 179:B 163:. 148:) 145:X 142:( 134:) 129:i 125:K 121:( 113:n 108:1 105:= 102:i 91:= 74:X 68:X 56:n 53:K 49:1 46:K

Index

fraction
packing problems
compact
measure space
Euclidean space
limit superior and limit inferior
supremum
Euclidean motions
Kepler conjecture
Ulam's packing conjecture
translations
Atomic packing factor
Sphere packing
List of shapes with known packing constant


doi
10.1007/BF02187693
Weisstein, Eric W.
"Packing Density"
MathWorld
Categories
Packing problems
Discrete geometry

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