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Generic polynomial

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The existence, and especially the construction, of a generic polynomial for a given Galois group provides a complete solution to the
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for that group. However, not all Galois groups have generic polynomials, a counterexample being the
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The cyclic group construction leads to other classes of generic polynomials; in particular the
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polynomial, which is generic relative to the rational numbers is called simply generic.
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is divisible by eight, and G. W. Smith explicitly constructs such a polynomial in case
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can be obtained as the splitting field of a polynomial which is the specialization of
1772: 111: 481: 391: 256: 194: 127: 29: 17: 25: 1425:, is defined as the minimal number of parameters in a generic polynomial for 1372:
Generic polynomials are known for all transitive groups of degree 5 or less.
115: 1283:{\displaystyle x^{5}+(t-3)x^{4}+(s-t+3)x^{3}+(t^{2}-t-2s-1)x^{2}+sx+t} 398:
showed that a cyclic group does not have a generic polynomial if
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are indeterminates, the generic polynomial of degree two in
946:{\displaystyle x^{4}-2s(t^{2}+1)x^{2}+s^{2}t^{2}(t^{2}+1)} 517:, including in particular groups of the root systems for 1710: 1661: 1612: 1563: 1514: 1465: 1439: 1398: 1309: 1142: 1065: 972: 846: 772: 716: 633: 587: 552:
of two groups both of which have generic polynomials.
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of two groups both of which have generic polynomials.
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Jensen, Christian U., Ledet, Arne, and Yui, Noriko,
1744: 1695: 1646: 1597: 1548: 1499: 1445: 1417: 1359: 1282: 1115: 1038: 945: 819: 750: 689: 606: 469: 351: 100: 352:{\displaystyle x^{n}+t_{1}x^{n-1}+\cdots +t_{n}} 122:has a different, although related, meaning: a 8: 560: 1039:{\displaystyle x^{4}-2stx^{2}+s^{2}t(t-1)} 1730: 1720: 1719: 1718: 1709: 1681: 1671: 1670: 1669: 1660: 1632: 1622: 1621: 1620: 1611: 1583: 1573: 1572: 1571: 1562: 1534: 1524: 1523: 1522: 1513: 1485: 1475: 1474: 1473: 1464: 1438: 1406: 1397: 1330: 1314: 1308: 1259: 1225: 1209: 1175: 1147: 1141: 1086: 1070: 1064: 1012: 999: 977: 971: 928: 915: 905: 892: 873: 851: 845: 802: 780: 771: 721: 715: 654: 638: 632: 592: 586: 459: 454: 448: 343: 318: 308: 295: 289: 74: 65: 1745:{\displaystyle gd_{\mathbb {Q} }S_{5}=2} 1696:{\displaystyle gd_{\mathbb {Q} }D_{5}=2} 1647:{\displaystyle gd_{\mathbb {Q} }S_{4}=2} 1598:{\displaystyle gd_{\mathbb {Q} }D_{4}=2} 1549:{\displaystyle gd_{\mathbb {Q} }S_{3}=1} 1500:{\displaystyle gd_{\mathbb {Q} }A_{3}=1} 421:has a generic polynomial if and only if 690:{\displaystyle x^{3}-tx^{2}+(t-3)x+1} 7: 1360:{\displaystyle x^{5}+sx^{3}-t(x+1)} 1116:{\displaystyle x^{4}+sx^{2}-t(x+1)} 1765:, Cambridge University Press, 2002 1440: 820:{\displaystyle (x^{2}-s)(x^{2}-t)} 14: 1453:if no generic polynomial exists. 204:, and such that every extension 118:, and in this article, the term 557:Examples of generic polynomials 513:Reflection groups defined over 263:Groups with generic polynomials 1354: 1342: 1252: 1218: 1202: 1184: 1168: 1156: 1110: 1098: 1033: 1021: 940: 921: 885: 866: 814: 795: 792: 773: 745: 733: 675: 663: 1: 751:{\displaystyle x^{3}-t(x+1)} 363:is a generic polynomial for 101:{\displaystyle ax^{2}+bx+c.} 232:. This is sometimes called 220:resulting from setting the 149:field of rational functions 1800: 425:is not divisible by eight. 406:is not divisible by eight. 470:{\displaystyle H_{p^{3}}} 236:or relative to the field 147:with coefficients in the 1446:{\displaystyle \infty } 1418:{\displaystyle gd_{F}G} 607:{\displaystyle x^{2}-t} 1746: 1697: 1648: 1599: 1550: 1501: 1447: 1419: 1361: 1284: 1117: 1040: 947: 821: 752: 691: 608: 503:The alternating group 471: 353: 253:inverse Galois problem 102: 1747: 1698: 1649: 1600: 1551: 1502: 1448: 1420: 1362: 1285: 1118: 1041: 948: 822: 753: 692: 609: 548:Any group which is a 541:Any group which is a 472: 354: 280:. This is trivial, as 103: 1708: 1659: 1610: 1561: 1512: 1463: 1437: 1396: 1307: 1140: 1063: 970: 844: 770: 714: 631: 585: 447: 288: 178:indeterminates over 64: 24:refers usually to a 1779:Field (mathematics) 1763:Generic Polynomials 1384:for a finite group 567:Generic Polynomial 1742: 1693: 1644: 1595: 1546: 1497: 1443: 1415: 1357: 1280: 1113: 1036: 943: 817: 748: 687: 604: 467: 349: 224:indeterminates to 212:with Galois group 124:generic polynomial 120:generic polynomial 98: 36:. For example, if 22:generic polynomial 1382:generic dimension 1376:Generic dimension 1370: 1369: 492:alternating group 442:Heisenberg groups 1791: 1751: 1749: 1748: 1743: 1735: 1734: 1725: 1724: 1723: 1702: 1700: 1699: 1694: 1686: 1685: 1676: 1675: 1674: 1653: 1651: 1650: 1645: 1637: 1636: 1627: 1626: 1625: 1604: 1602: 1601: 1596: 1588: 1587: 1578: 1577: 1576: 1555: 1553: 1552: 1547: 1539: 1538: 1529: 1528: 1527: 1506: 1504: 1503: 1498: 1490: 1489: 1480: 1479: 1478: 1452: 1450: 1449: 1444: 1424: 1422: 1421: 1416: 1411: 1410: 1366: 1364: 1363: 1358: 1335: 1334: 1319: 1318: 1289: 1287: 1286: 1281: 1264: 1263: 1230: 1229: 1214: 1213: 1180: 1179: 1152: 1151: 1122: 1120: 1119: 1114: 1091: 1090: 1075: 1074: 1045: 1043: 1042: 1037: 1017: 1016: 1004: 1003: 982: 981: 952: 950: 949: 944: 933: 932: 920: 919: 910: 909: 897: 896: 878: 877: 856: 855: 826: 824: 823: 818: 807: 806: 785: 784: 757: 755: 754: 749: 726: 725: 696: 694: 693: 688: 659: 658: 643: 642: 613: 611: 610: 605: 597: 596: 561: 476: 474: 473: 468: 466: 465: 464: 463: 430:quaternion group 358: 356: 355: 350: 348: 347: 329: 328: 313: 312: 300: 299: 259:of order eight. 182:, such that the 142:monic polynomial 107: 105: 104: 99: 79: 78: 59: 53: 47: 41: 1799: 1798: 1794: 1793: 1792: 1790: 1789: 1788: 1769: 1768: 1758: 1726: 1714: 1706: 1705: 1677: 1665: 1657: 1656: 1628: 1616: 1608: 1607: 1579: 1567: 1559: 1558: 1530: 1518: 1510: 1509: 1481: 1469: 1461: 1460: 1435: 1434: 1402: 1394: 1393: 1378: 1326: 1310: 1305: 1304: 1301: 1255: 1221: 1205: 1171: 1143: 1138: 1137: 1134: 1082: 1066: 1061: 1060: 1057: 1008: 995: 973: 968: 967: 964: 924: 911: 901: 888: 869: 847: 842: 841: 838: 798: 776: 768: 767: 717: 712: 711: 708: 650: 634: 629: 628: 625: 588: 583: 582: 579: 559: 537: 530: 523: 509: 499: 455: 450: 445: 444: 437: 420: 385: 371: 339: 314: 304: 291: 286: 285: 279: 270:symmetric group 265: 184:splitting field 173: 164: 70: 62: 61: 55: 49: 43: 37: 12: 11: 5: 1797: 1795: 1787: 1786: 1781: 1771: 1770: 1767: 1766: 1757: 1754: 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881: 876: 872: 868: 865: 862: 859: 854: 850: 839: 834: 828: 827: 816: 813: 810: 805: 801: 797: 794: 791: 788: 783: 779: 775: 765: 759: 758: 747: 744: 741: 738: 735: 732: 729: 724: 720: 709: 704: 698: 697: 686: 683: 680: 677: 674: 671: 668: 665: 662: 657: 653: 649: 646: 641: 637: 626: 621: 615: 614: 603: 600: 595: 591: 580: 575: 569: 568: 565: 558: 555: 554: 553: 550:wreath product 546: 543:direct product 539: 535: 528: 521: 511: 507: 501: 497: 488: 462: 458: 453: 439: 435: 426: 416: 411:dihedral group 407: 381: 377:Cyclic groups 374: 373: 367: 360: 359: 346: 342: 338: 335: 332: 327: 324: 321: 317: 311: 307: 303: 298: 294: 282: 281: 275: 264: 261: 169: 162: 114:, a branch of 97: 94: 91: 88: 85: 82: 77: 73: 69: 34:indeterminates 13: 10: 9: 6: 4: 3: 2: 1796: 1785: 1784:Galois theory 1782: 1780: 1777: 1776: 1774: 1764: 1760: 1759: 1755: 1739: 1736: 1731: 1727: 1715: 1711: 1704: 1690: 1687: 1682: 1678: 1666: 1662: 1655: 1641: 1638: 1633: 1629: 1617: 1613: 1606: 1592: 1589: 1584: 1580: 1568: 1564: 1557: 1543: 1540: 1535: 1531: 1519: 1515: 1508: 1494: 1491: 1486: 1482: 1470: 1466: 1459: 1458: 1457: 1454: 1432: 1428: 1412: 1407: 1403: 1399: 1391: 1388:over a field 1387: 1383: 1375: 1373: 1351: 1348: 1345: 1339: 1336: 1331: 1327: 1323: 1320: 1315: 1311: 1303: 1300: 1296: 1293: 1292: 1277: 1274: 1271: 1268: 1265: 1260: 1256: 1249: 1246: 1243: 1240: 1237: 1234: 1231: 1226: 1222: 1215: 1210: 1206: 1199: 1196: 1193: 1190: 1187: 1181: 1176: 1172: 1165: 1162: 1159: 1153: 1148: 1144: 1136: 1133: 1129: 1126: 1125: 1107: 1104: 1101: 1095: 1092: 1087: 1083: 1079: 1076: 1071: 1067: 1059: 1056: 1052: 1049: 1048: 1030: 1027: 1024: 1018: 1013: 1009: 1005: 1000: 996: 992: 989: 986: 983: 978: 974: 966: 963: 959: 956: 955: 937: 934: 929: 925: 916: 912: 906: 902: 898: 893: 889: 882: 879: 874: 870: 863: 860: 857: 852: 848: 840: 837: 833: 830: 829: 811: 808: 803: 799: 789: 786: 781: 777: 766: 764: 761: 760: 742: 739: 736: 730: 727: 722: 718: 710: 707: 703: 700: 699: 684: 681: 678: 672: 669: 666: 660: 655: 651: 647: 644: 639: 635: 627: 624: 620: 617: 616: 601: 598: 593: 589: 581: 578: 574: 571: 570: 566: 563: 562: 556: 551: 547: 544: 540: 534: 527: 520: 516: 512: 506: 502: 496: 493: 489: 486: 483: 480: 460: 456: 451: 443: 440: 434: 431: 427: 424: 419: 415: 412: 408: 405: 401: 397: 393: 389: 384: 380: 376: 375: 370: 366: 362: 361: 344: 340: 336: 333: 330: 325: 322: 319: 315: 309: 305: 301: 296: 292: 284: 283: 278: 274: 271: 267: 266: 262: 260: 258: 254: 249: 247: 243: 239: 235: 231: 227: 223: 219: 215: 211: 207: 203: 199: 196: 192: 188: 185: 181: 177: 172: 168: 161: 157: 153: 150: 146: 143: 139: 136: 132: 129: 125: 121: 117: 113: 112:Galois theory 108: 95: 92: 89: 86: 83: 80: 75: 71: 67: 58: 52: 46: 40: 35: 31: 27: 23: 19: 1762: 1756:Publications 1455: 1430: 1426: 1389: 1385: 1381: 1379: 1371: 1298: 1294: 1131: 1127: 1054: 1050: 961: 957: 835: 831: 762: 705: 701: 622: 618: 576: 572: 532: 525: 518: 514: 504: 494: 484: 432: 422: 417: 413: 403: 399: 387: 382: 378: 368: 364: 276: 272: 257:cyclic group 250: 245: 241: 237: 233: 229: 228:elements of 225: 221: 217: 213: 209: 205: 201: 197: 195:Galois group 190: 186: 179: 175: 170: 166: 159: 155: 151: 144: 137: 130: 128:finite group 123: 119: 109: 56: 50: 44: 38: 30:coefficients 21: 15: 110:However in 18:mathematics 1773:Categories 1456:Examples: 1392:, denoted 394:by eight. 26:polynomial 1441:∞ 1337:− 1247:− 1238:− 1232:− 1191:− 1163:− 1093:− 1028:− 984:− 858:− 809:− 787:− 728:− 670:− 645:− 599:− 392:divisible 334:⋯ 323:− 234:F-generic 477:for any 386:, where 396:Lenstra 390:is not 246:generic 165:, ..., 116:algebra 531:, and 133:and a 126:for a 48:, and 28:whose 1433:, or 1429:over 564:Group 482:prime 200:over 174:) in 140:is a 135:field 1380:The 490:The 428:The 268:The 240:; a 193:has 32:are 20:, a 479:odd 189:of 60:is 16:In 1775:: 524:, 154:= 42:, 1740:2 1737:= 1732:5 1728:S 1721:Q 1716:d 1712:g 1691:2 1688:= 1683:5 1679:D 1672:Q 1667:d 1663:g 1642:2 1639:= 1634:4 1630:S 1623:Q 1618:d 1614:g 1593:2 1590:= 1585:4 1581:D 1574:Q 1569:d 1565:g 1544:1 1541:= 1536:3 1532:S 1525:Q 1520:d 1516:g 1495:1 1492:= 1487:3 1483:A 1476:Q 1471:d 1467:g 1431:F 1427:G 1413:G 1408:F 1404:d 1400:g 1390:F 1386:G 1355:) 1352:1 1349:+ 1346:x 1343:( 1340:t 1332:3 1328:x 1324:s 1321:+ 1316:5 1312:x 1299:5 1295:S 1278:t 1275:+ 1272:x 1269:s 1266:+ 1261:2 1257:x 1253:) 1250:1 1244:s 1241:2 1235:t 1227:2 1223:t 1219:( 1216:+ 1211:3 1207:x 1203:) 1200:3 1197:+ 1194:t 1188:s 1185:( 1182:+ 1177:4 1173:x 1169:) 1166:3 1160:t 1157:( 1154:+ 1149:5 1145:x 1132:5 1128:D 1111:) 1108:1 1105:+ 1102:x 1099:( 1096:t 1088:2 1084:x 1080:s 1077:+ 1072:4 1068:x 1055:4 1051:S 1034:) 1031:1 1025:t 1022:( 1019:t 1014:2 1010:s 1006:+ 1001:2 997:x 993:t 990:s 987:2 979:4 975:x 962:4 958:D 941:) 938:1 935:+ 930:2 926:t 922:( 917:2 913:t 907:2 903:s 899:+ 894:2 890:x 886:) 883:1 880:+ 875:2 871:t 867:( 864:s 861:2 853:4 849:x 836:4 832:C 815:) 812:t 804:2 800:x 796:( 793:) 790:s 782:2 778:x 774:( 763:V 746:) 743:1 740:+ 737:x 734:( 731:t 723:3 719:x 706:3 702:S 685:1 682:+ 679:x 676:) 673:3 667:t 664:( 661:+ 656:2 652:x 648:t 640:3 636:x 623:3 619:C 602:t 594:2 590:x 577:2 573:C 538:. 536:8 533:E 529:7 526:E 522:6 519:E 515:Q 510:. 508:5 505:A 500:. 498:4 495:A 487:. 485:p 461:3 457:p 452:H 438:. 436:8 433:Q 423:n 418:n 414:D 404:n 400:n 388:n 383:n 379:C 372:. 369:n 365:S 345:n 341:t 337:+ 331:+ 326:1 320:n 316:x 310:1 306:t 302:+ 297:n 293:x 277:n 273:S 244:- 242:Q 238:F 230:F 226:n 222:n 218:P 214:G 210:F 208:/ 206:K 202:L 198:G 191:P 187:M 180:F 176:n 171:n 167:t 163:1 160:t 158:( 156:F 152:L 145:P 138:F 131:G 96:. 93:c 90:+ 87:x 84:b 81:+ 76:2 72:x 68:a 57:x 51:c 45:b 39:a

Index

mathematics
polynomial
coefficients
indeterminates
Galois theory
algebra
finite group
field
monic polynomial
field of rational functions
splitting field
Galois group
inverse Galois problem
cyclic group
symmetric group
divisible
Lenstra
dihedral group
quaternion group
Heisenberg groups
odd
prime
alternating group
direct product
wreath product
Categories
Field (mathematics)
Galois theory

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