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Algebraic matroid

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for each row of the matrix, and by using the matrix coefficients within each column to assign each matroid element a linear combination of these transcendentals. For fields of characteristic zero (such as the real numbers) linear and algebraic matroids coincide, but for other fields there may exist
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algebraic matroids that are not linear; indeed the non-Pappus matroid is algebraic over any finite field, but not linear and not algebraic over any field of characteristic zero. However, if a matroid is algebraic over a field
539: 141:, in which the matroid elements correspond to matrix columns, and a set of elements is independent if the corresponding set of columns is 355: 117:. No good characterization of algebraic matroids is known, but certain matroids are known to be non-algebraic; the smallest is the 658: 631: 601: 480: 97:. In this matroid, the rank of a set of elements is its transcendence degree, and the flat generated by a set 228:
The class of algebraic matroids is closed under truncation and matroid union. It is not known whether the
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of an algebraic matroid is always algebraic and there is no excluded minor characterisation of the class.
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can be used to show that there always exists a maximal algebraically independent subset of
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Lindström, Bernt (1985). "On the algebraic characteristic set for a class of matroids".
643: 556: 654: 627: 597: 476: 179: 664: 607: 564: 548: 453: 380: 364: 195: 118: 445: 372: 59: 48: 678: 649:, Encyclopedia of Mathematics and its Applications, vol. 29, Cambridge: 619: 210: 32: 368: 229: 70:. Further, all the maximal algebraically independent subsets have the same 442:
Combinatorial Mathematics and its Applications (Proc. Conf., Oxford, 1969)
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Ingleton, A. W.; Main, R. A. (1975). "Non-algebraic matroids exist".
552: 209:. It follows that the class of algebraic matroids is closed under 286:
Every prime occurs as the unique characteristic for some matroid.
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structure, that expresses an abstraction of the relation of
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satisfy the axioms that define the independent sets of a
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Ingleton, A. W. (1971). "Representation of matroids".
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may also be represented as an algebraic matroid over
642: 676: 540:Proceedings of the American Mathematical Society 162:of characteristic zero then it is linear over 124: 444:. London: Academic Press. pp. 149–167. 352: 275:) then all sufficiently large primes are in 356:Bulletin of the London Mathematical Society 89:, the algebraically independent subsets of 536: 514: 512: 510: 170:) for some finite set of transcendentals 439: 426: 424: 422: 420: 418: 416: 592:. Oxford Science Publications. Oxford: 530: 397: 395: 677: 507: 475:, New Age International, p. 909, 640: 618: 584: 521: 498: 489: 470: 413: 235: 189: 16:Abstraction of algebraic independence 404: 392: 337: 328: 319: 213:, and that a matroid algebraic over 101:of elements is the intersection of 13: 14: 696: 194:If a matroid is algebraic over a 263:is algebraically representable. 626:. Courier Dover Publications. 464: 433: 346: 242:(algebraic) characteristic set 1: 578: 305:and hence so is any minor of 42: 205:) then it is algebraic over 129:Many finite matroids may be 7: 473:Applied Discrete Structures 125:Relation to linear matroids 115:algebraically representable 10: 701: 651:Cambridge University Press 641:White, Neil, ed. (1987), 645:Combinatorial geometries 313: 297:then any contraction of 594:Oxford University Press 255:is the set of possible 217:is algebraic over the 37:algebraic independence 471:Joshi, K. D. (1997), 259:of fields over which 81:For every finite set 369:10.1112/blms/7.2.144 143:linearly independent 76:transcendence degree 527:Oxley (1992) p.223 504:Oxley (1992) p.224 495:Oxley (1992) p.222 410:Oxley (1992) p.220 401:Oxley (1992) p.221 343:Oxley (1992) p.215 334:Oxley (1992) p.218 325:Oxley (1992) p.216 301:is algebraic over 293:is algebraic over 236:Characteristic set 190:Closure properties 78:of the extension. 518:White (1987) p.25 430:White (1987) p.24 180:algebraic closure 153:, by choosing an 25:algebraic matroid 692: 671: 648: 637: 615: 573: 572: 534: 528: 525: 519: 516: 505: 502: 496: 493: 487: 485: 468: 462: 461: 437: 431: 428: 411: 408: 402: 399: 390: 388: 350: 344: 341: 335: 332: 326: 323: 196:simple extension 700: 699: 695: 694: 693: 691: 690: 689: 675: 674: 661: 634: 620:Welsh, D. J. A. 604: 586:Oxley, James G. 581: 576: 553:10.2307/2045591 535: 531: 526: 522: 517: 508: 503: 499: 494: 490: 483: 469: 465: 438: 434: 429: 414: 409: 405: 400: 393: 351: 347: 342: 338: 333: 329: 324: 320: 316: 257:characteristics 251:) of a matroid 238: 192: 127: 105:with the field 85:of elements of 74:, known as the 49:field extension 45: 17: 12: 11: 5: 698: 688: 687: 685:Matroid theory 673: 672: 659: 638: 632: 624:Matroid Theory 616: 602: 590:Matroid theory 580: 577: 575: 574: 547:(1): 147–151. 529: 520: 506: 497: 488: 481: 463: 432: 412: 403: 391: 363:(2): 144–146. 345: 336: 327: 317: 315: 312: 311: 310: 287: 284: 237: 234: 191: 188: 126: 123: 44: 41: 15: 9: 6: 4: 3: 2: 697: 686: 683: 682: 680: 670: 666: 662: 660:0-521-33339-3 656: 652: 647: 646: 639: 635: 633:9780486474397 629: 625: 621: 617: 613: 609: 605: 603:0-19-853563-5 599: 595: 591: 587: 583: 582: 570: 566: 562: 558: 554: 550: 546: 542: 541: 533: 524: 515: 513: 511: 501: 492: 484: 482:9788122408263 478: 474: 467: 459: 455: 451: 447: 443: 436: 427: 425: 423: 421: 419: 417: 407: 398: 396: 386: 382: 378: 374: 370: 366: 362: 358: 357: 349: 340: 331: 322: 318: 308: 304: 300: 296: 292: 288: 285: 282: 278: 274: 270: 266: 265: 264: 262: 258: 254: 250: 246: 243: 233: 231: 226: 224: 220: 216: 212: 208: 204: 200: 197: 187: 185: 181: 178:and over the 177: 173: 169: 165: 161: 156: 155:indeterminate 152: 148: 144: 140: 137:over a field 136: 132: 122: 120: 119:Vámos matroid 116: 112: 108: 104: 100: 96: 92: 88: 84: 79: 77: 73: 69: 65: 61: 57: 53: 50: 40: 38: 34: 33:combinatorial 30: 26: 22: 644: 623: 589: 544: 538: 532: 523: 500: 491: 472: 466: 441: 435: 406: 360: 354: 348: 339: 330: 321: 306: 302: 298: 294: 290: 280: 276: 272: 268: 260: 252: 248: 244: 241: 239: 227: 222: 214: 206: 202: 198: 193: 183: 175: 171: 167: 163: 159: 150: 146: 138: 128: 114: 110: 106: 102: 98: 90: 86: 82: 80: 67: 63: 60:Zorn's lemma 55: 51: 46: 24: 18: 267:If 0 is in 219:prime field 211:contraction 131:represented 72:cardinality 21:mathematics 669:0626.00007 612:0784.05002 579:References 569:0572.05019 458:0222.05025 385:0315.05018 43:Definition 622:(2010) . 111:algebraic 679:Category 588:(1992). 47:Given a 561:2045591 450:0278974 377:0369110 95:matroid 29:matroid 667:  657:  630:  610:  600:  567:  559:  479:  456:  448:  383:  375:  135:matrix 557:JSTOR 314:Notes 174:over 133:by a 66:over 27:is a 23:, an 655:ISBN 628:ISBN 598:ISBN 477:ISBN 240:The 230:dual 31:, a 665:Zbl 608:Zbl 565:Zbl 549:doi 454:Zbl 381:Zbl 365:doi 289:If 221:of 182:of 113:or 19:In 681:: 663:, 653:, 606:. 596:. 563:. 555:. 545:95 543:. 509:^ 452:. 446:MR 415:^ 394:^ 379:. 373:MR 371:. 359:. 283:). 225:. 186:. 121:. 58:, 39:. 636:. 614:. 571:. 551:: 486:. 460:. 389:. 387:. 367:: 361:7 309:. 307:M 303:F 299:M 295:F 291:M 281:M 279:( 277:K 273:M 271:( 269:K 261:M 253:M 249:M 247:( 245:K 223:F 215:F 207:F 203:t 201:( 199:F 184:F 176:F 172:T 168:T 166:( 164:F 160:F 151:F 147:F 139:K 107:K 103:L 99:T 91:S 87:L 83:S 68:K 64:L 56:K 54:/ 52:L

Index

mathematics
matroid
combinatorial
algebraic independence
field extension
Zorn's lemma
cardinality
transcendence degree
matroid
Vámos matroid
represented
matrix
linearly independent
indeterminate
algebraic closure
simple extension
contraction
prime field
dual
characteristics
Bulletin of the London Mathematical Society
doi
10.1112/blms/7.2.144
MR
0369110
Zbl
0315.05018


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