Knowledge (XXG)

Theorem of the highest weight

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constructs an irreducible representation as the space of global sections of an ample line bundle; the highest weight theorem results as a consequence. (The approach uses a fair bit of algebraic geometry but yields a very quick
1449:. Every analytically integral element is integral in the Lie algebra sense, but there may be integral elements in the Lie algebra sense that are not analytically integral. This distinction reflects the fact that if 1246: 1107: 1598:
approach: one constructs irreducible representations as subrepresentations of a tensor power of the standard representations. This approach is essentially due to H. Weyl and works quite well for classical
529: 599: 487: 335: 1320: 1359: 1292:. The theory then proceeds in much the same way as in the Lie algebra case, with one crucial difference: the notion of integrality is different. Specifically, we say that an element 673: 562: 122: 1491: 1270: 1199: 1131: 1060: 928: 813: 274: 247: 149: 53: 743: 1404: 994: 974: 837: 769: 693: 622: 203: 423: 450: 857: 717: 642: 347: 1554: 1531: 1511: 1467: 1447: 1427: 1290: 1175: 1151: 1032: 948: 904: 877: 789: 294: 189: 169: 80: 1954: 1683:"Reviewed work: Matrix Groups: An Introduction to Lie Group Theory, Andrew Baker; Lie Groups: An Introduction through Linear Groups, Wulf Rossmann" 1000:
The most difficult part is the last one; the construction of a finite-dimensional irreducible representation with a prescribed highest weight.
1920: 1860: 1815: 1204: 1065: 1895: 171:. The difference between the two results is in the precise notion of "integral" in the definition of a dominant integral element. If 1587: 1949: 1583:
contains the highest weight theorem. This is the approach taken in many standard textbooks (e.g., Humphreys and Part II of Hall).
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from the set of "dominant integral elements" to the set of equivalence classes of irreducible representations of
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is then the same as in the Lie algebra case, except that "integral" is replaced by "analytically integral."
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If two finite-dimensional irreducible representations have the same highest weight, they are isomorphic.
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Weight (representation theory) § Weights in the representation theory of semisimple Lie algebras
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is expressible as a linear combination of positive roots with non-negative real coefficients.
678: 607: 250: 408: 1848: 1694: 1595: 395:{\displaystyle 2{\frac {\langle \lambda ,\alpha \rangle }{\langle \alpha ,\alpha \rangle }}} 1870: 1825: 428: 1866: 1821: 842: 702: 627: 1539: 1516: 1496: 1452: 1432: 1412: 1275: 1160: 1136: 1017: 933: 889: 862: 774: 279: 195: 174: 154: 65: 1933: 1909: 1614: 1533:
is simply connected, the notions of "integral" and "analytically integral" coincide.
1154: 1035: 1009: 56: 1580: 976:, there exists a finite-dimensional irreducible representation with highest weight 199: 1797: 1568:
Hermann Weyl's original proof from the compact group point of view, based on the
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in his 1913 paper. The version of the theorem for a compact Lie group is due to
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Compact group § Representation theory of a connected compact Lie group
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has a unique highest weight, and this highest weight is dominant integral.
1890:, Graduate Texts in Mathematics, vol. 222 (2nd ed.), Springer, 1888:
Lie groups, Lie algebras, and representations: An elementary introduction
1706: 1682: 1847:, Readings in Mathematics. Vol. 129. New York: Springer-Verlag. 1698: 1241:{\displaystyle {\mathfrak {h}}:={\mathfrak {t}}+i{\mathfrak {t}}} 1102:{\displaystyle {\mathfrak {g}}:={\mathfrak {k}}+i{\mathfrak {k}}} 1620:
Weights in the representation theory of semisimple Lie algebras
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Classifying finite-dimensional representations of Lie algebras
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be a finite-dimensional semisimple complex Lie algebra with
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The theorem of the highest weight for representations of
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is not simply connected, there may be representations of
1911:
Introduction to Lie Algebras and Representation Theory
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Representation theory of a connected compact Lie group
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is a finite-dimensional irreducible representation of
524:{\displaystyle \langle \lambda ,\alpha \rangle \geq 0} 1542: 1519: 1499: 1475: 1455: 1435: 1415: 1373: 1335: 1298: 1278: 1254: 1207: 1183: 1163: 1139: 1115: 1068: 1044: 1020: 982: 962: 936: 912: 892: 865: 845: 825: 797: 777: 757: 725: 705: 681: 650: 630: 610: 570: 537: 499: 458: 431: 411: 350: 306: 282: 258: 231: 177: 157: 133: 91: 68: 55:. There is a closely related theorem classifying the 37: 1908: 1548: 1525: 1505: 1485: 1461: 1441: 1421: 1398: 1353: 1314: 1284: 1264: 1240: 1193: 1169: 1145: 1125: 1101: 1054: 1026: 988: 968: 942: 922: 898: 871: 851: 831: 807: 783: 763: 737: 711: 687: 667: 636: 616: 593: 556: 523: 481: 444: 417: 394: 329: 288: 268: 241: 191:is simply connected, this distinction disappears. 183: 163: 143: 116: 74: 47: 604:if it is both dominant and integral. Finally, if 204:representation theory of semisimple Lie algebras 882:The theorem of the highest weight then states: 594:{\displaystyle \lambda \in {\mathfrak {h}}^{*}} 482:{\displaystyle \lambda \in {\mathfrak {h}}^{*}} 330:{\displaystyle \lambda \in {\mathfrak {h}}^{*}} 82:. The theorem states that there is a bijection 1649: 1647: 1272:, and we may form the associated root system 452:of positive roots and we say that an element 8: 1348: 1336: 512: 500: 386: 374: 369: 357: 1315:{\displaystyle \lambda \in {\mathfrak {h}}} 1354:{\displaystyle \langle \lambda ,H\rangle } 202:. The theorem is one of the key pieces of 1541: 1518: 1498: 1493:that do not come from representations of 1477: 1476: 1474: 1454: 1434: 1414: 1378: 1372: 1334: 1306: 1305: 1297: 1277: 1256: 1255: 1253: 1232: 1231: 1219: 1218: 1209: 1208: 1206: 1185: 1184: 1182: 1162: 1138: 1117: 1116: 1114: 1093: 1092: 1080: 1079: 1070: 1069: 1067: 1046: 1045: 1043: 1019: 981: 961: 935: 914: 913: 911: 891: 864: 844: 824: 799: 798: 796: 776: 756: 724: 704: 680: 659: 653: 652: 649: 629: 609: 585: 579: 578: 569: 548: 536: 498: 473: 467: 466: 457: 436: 430: 410: 354: 349: 321: 315: 314: 305: 281: 260: 259: 257: 233: 232: 230: 176: 156: 135: 134: 132: 105: 90: 67: 39: 38: 36: 1638: 1631: 1664: 1662: 1841:Representation theory. A first course 194:The theorem was originally proved by 7: 1779: 1767: 1755: 1743: 1731: 1719: 1668: 1653: 1478: 1307: 1257: 1233: 1220: 1210: 1186: 1118: 1094: 1081: 1071: 1047: 956:For each dominant integral element 915: 800: 668:{\displaystyle {\mathfrak {h}}^{*}} 654: 580: 468: 316: 261: 234: 136: 40: 1806:, vol. 11, Providence, R.I.: 839:is higher than every other weight 14: 1955:Theorems in representation theory 1687:The American Mathematical Monthly 1564:There are at least four proofs: 557:{\displaystyle \alpha \in R^{+}} 117:{\displaystyle \lambda \mapsto } 1804:Graduate Studies in Mathematics 1486:{\displaystyle {\mathfrak {g}}} 1265:{\displaystyle {\mathfrak {g}}} 1194:{\displaystyle {\mathfrak {t}}} 1126:{\displaystyle {\mathfrak {g}}} 1055:{\displaystyle {\mathfrak {k}}} 923:{\displaystyle {\mathfrak {g}}} 808:{\displaystyle {\mathfrak {g}}} 269:{\displaystyle {\mathfrak {h}}} 242:{\displaystyle {\mathfrak {g}}} 144:{\displaystyle {\mathfrak {g}}} 48:{\displaystyle {\mathfrak {g}}} 20:, a branch of mathematics, the 300:. We then say that an element 111: 98: 95: 1: 1845:Graduate Texts in Mathematics 1808:American Mathematical Society 738:{\displaystyle \lambda -\mu } 22:theorem of the highest weight 1399:{\displaystyle e^{2\pi H}=I} 405:is an integer for each root 1429:is the identity element of 1109:be the complexification of 57:irreducible representations 26:irreducible representations 1971: 1796:Dixmier, Jacques (1996) , 1248:is a Cartan subalgebra of 1007: 218: 1853:10.1007/978-1-4612-0979-9 1513:. On the other hand, if 989:{\displaystyle \lambda } 969:{\displaystyle \lambda } 832:{\displaystyle \lambda } 764:{\displaystyle \lambda } 688:{\displaystyle \lambda } 617:{\displaystyle \lambda } 425:. Next, we choose a set 1950:Theorems about algebras 1886:Hall, Brian C. (2015), 1588:Borel–Weil–Bott theorem 1364:is an integer whenever 418:{\displaystyle \alpha } 59:of a connected compact 1570:Weyl character formula 1550: 1527: 1507: 1487: 1463: 1443: 1423: 1400: 1355: 1316: 1286: 1266: 1242: 1195: 1171: 1147: 1127: 1103: 1056: 1028: 1004:The compact group case 990: 970: 944: 924: 900: 873: 853: 833: 809: 785: 765: 739: 713: 689: 669: 638: 618: 595: 558: 525: 483: 446: 419: 396: 331: 290: 270: 243: 185: 165: 145: 118: 76: 49: 30:semisimple Lie algebra 1940:Representation theory 1681:Knapp, A. W. (2003). 1551: 1528: 1508: 1488: 1464: 1444: 1424: 1401: 1356: 1324:analytically integral 1317: 1287: 1267: 1243: 1196: 1172: 1148: 1128: 1104: 1057: 1029: 991: 971: 945: 925: 901: 874: 854: 834: 810: 786: 766: 740: 714: 690: 670: 639: 619: 596: 559: 526: 484: 447: 445:{\displaystyle R^{+}} 420: 397: 332: 291: 271: 244: 186: 166: 146: 119: 77: 50: 18:representation theory 1656:Theorems 9.4 and 9.5 1540: 1517: 1497: 1473: 1453: 1433: 1413: 1371: 1333: 1296: 1276: 1252: 1205: 1181: 1161: 1137: 1113: 1066: 1042: 1018: 980: 960: 934: 910: 890: 863: 852:{\displaystyle \mu } 843: 823: 795: 775: 771:of a representation 755: 723: 712:{\displaystyle \mu } 703: 679: 648: 637:{\displaystyle \mu } 628: 608: 568: 535: 497: 456: 429: 409: 348: 304: 280: 256: 229: 175: 155: 131: 89: 66: 35: 1905:Humphreys, James E. 1799:Enveloping algebras 1596:invariant theoretic 1574:Peter–Weyl theorem 1546: 1523: 1503: 1483: 1459: 1439: 1419: 1396: 1351: 1312: 1282: 1262: 1238: 1191: 1167: 1143: 1123: 1099: 1052: 1024: 986: 966: 940: 920: 896: 869: 849: 829: 805: 781: 761: 735: 709: 685: 665: 634: 614: 591: 554: 521: 479: 442: 415: 392: 327: 296:be the associated 286: 266: 239: 181: 161: 141: 114: 72: 45: 1922:978-0-387-90053-7 1862:978-0-387-97495-8 1817:978-0-8218-0560-2 1549:{\displaystyle K} 1526:{\displaystyle K} 1506:{\displaystyle K} 1462:{\displaystyle K} 1442:{\displaystyle K} 1422:{\displaystyle I} 1285:{\displaystyle R} 1177:with Lie algebra 1170:{\displaystyle K} 1146:{\displaystyle T} 1038:with Lie algebra 1036:compact Lie group 1027:{\displaystyle K} 943:{\displaystyle V} 899:{\displaystyle V} 872:{\displaystyle V} 815:is then called a 784:{\displaystyle V} 602:dominant integral 390: 289:{\displaystyle R} 251:Cartan subalgebra 184:{\displaystyle K} 164:{\displaystyle K} 75:{\displaystyle K} 1962: 1925: 1914: 1900: 1882: 1828: 1783: 1777: 1771: 1765: 1759: 1758:Proposition 12.7 1753: 1747: 1741: 1735: 1729: 1723: 1717: 1711: 1710: 1678: 1672: 1666: 1657: 1651: 1642: 1641:, Theorem 7.2.6. 1636: 1555: 1553: 1552: 1547: 1532: 1530: 1529: 1524: 1512: 1510: 1509: 1504: 1492: 1490: 1489: 1484: 1482: 1481: 1468: 1466: 1465: 1460: 1448: 1446: 1445: 1440: 1428: 1426: 1425: 1420: 1405: 1403: 1402: 1397: 1389: 1388: 1360: 1358: 1357: 1352: 1321: 1319: 1318: 1313: 1311: 1310: 1291: 1289: 1288: 1283: 1271: 1269: 1268: 1263: 1261: 1260: 1247: 1245: 1244: 1239: 1237: 1236: 1224: 1223: 1214: 1213: 1200: 1198: 1197: 1192: 1190: 1189: 1176: 1174: 1173: 1168: 1152: 1150: 1149: 1144: 1132: 1130: 1129: 1124: 1122: 1121: 1108: 1106: 1105: 1100: 1098: 1097: 1085: 1084: 1075: 1074: 1061: 1059: 1058: 1053: 1051: 1050: 1033: 1031: 1030: 1025: 995: 993: 992: 987: 975: 973: 972: 967: 949: 947: 946: 941: 929: 927: 926: 921: 919: 918: 905: 903: 902: 897: 878: 876: 875: 870: 858: 856: 855: 850: 838: 836: 835: 830: 814: 812: 811: 806: 804: 803: 790: 788: 787: 782: 770: 768: 767: 762: 744: 742: 741: 736: 718: 716: 715: 710: 694: 692: 691: 686: 674: 672: 671: 666: 664: 663: 658: 657: 643: 641: 640: 635: 623: 621: 620: 615: 600: 598: 597: 592: 590: 589: 584: 583: 563: 561: 560: 555: 553: 552: 530: 528: 527: 522: 488: 486: 485: 480: 478: 477: 472: 471: 451: 449: 448: 443: 441: 440: 424: 422: 421: 416: 401: 399: 398: 393: 391: 389: 372: 355: 336: 334: 333: 328: 326: 325: 320: 319: 295: 293: 292: 287: 275: 273: 272: 267: 265: 264: 248: 246: 245: 240: 238: 237: 215:Lie algebra case 190: 188: 187: 182: 170: 168: 167: 162: 150: 148: 147: 142: 140: 139: 123: 121: 120: 115: 110: 109: 81: 79: 78: 73: 54: 52: 51: 46: 44: 43: 1970: 1969: 1965: 1964: 1963: 1961: 1960: 1959: 1930: 1929: 1923: 1903: 1898: 1885: 1863: 1833:Fulton, William 1831: 1818: 1795: 1792: 1787: 1786: 1778: 1774: 1770:Corollary 13.20 1766: 1762: 1754: 1750: 1746:Definition 12.4 1742: 1738: 1730: 1726: 1718: 1714: 1699:10.2307/3647845 1680: 1679: 1675: 1667: 1660: 1652: 1645: 1637: 1633: 1628: 1606: 1562: 1538: 1537: 1515: 1514: 1495: 1494: 1471: 1470: 1451: 1450: 1431: 1430: 1411: 1410: 1374: 1369: 1368: 1331: 1330: 1294: 1293: 1274: 1273: 1250: 1249: 1203: 1202: 1179: 1178: 1159: 1158: 1135: 1134: 1111: 1110: 1064: 1063: 1040: 1039: 1034:be a connected 1016: 1015: 1012: 1006: 978: 977: 958: 957: 932: 931: 908: 907: 888: 887: 861: 860: 841: 840: 821: 820: 793: 792: 773: 772: 753: 752: 721: 720: 701: 700: 677: 676: 651: 646: 645: 626: 625: 606: 605: 577: 566: 565: 544: 533: 532: 495: 494: 465: 454: 453: 432: 427: 426: 407: 406: 373: 356: 346: 345: 313: 302: 301: 278: 277: 254: 253: 227: 226: 223: 217: 212: 173: 172: 153: 152: 129: 128: 101: 87: 86: 64: 63: 33: 32: 24:classifies the 12: 11: 5: 1968: 1966: 1958: 1957: 1952: 1947: 1942: 1932: 1931: 1928: 1927: 1921: 1915:, Birkhäuser, 1901: 1897:978-3319134666 1896: 1883: 1861: 1829: 1816: 1791: 1788: 1785: 1784: 1772: 1760: 1748: 1736: 1724: 1712: 1693:(5): 446–455. 1673: 1658: 1643: 1630: 1629: 1627: 1624: 1623: 1622: 1617: 1612: 1605: 1602: 1601: 1600: 1592: 1584: 1579:The theory of 1577: 1561: 1558: 1545: 1522: 1502: 1480: 1458: 1438: 1418: 1407: 1406: 1395: 1392: 1387: 1384: 1381: 1377: 1362: 1361: 1350: 1347: 1344: 1341: 1338: 1309: 1304: 1301: 1281: 1259: 1235: 1230: 1227: 1222: 1217: 1212: 1188: 1166: 1142: 1120: 1096: 1091: 1088: 1083: 1078: 1073: 1049: 1023: 1005: 1002: 998: 997: 985: 965: 954: 951: 939: 917: 895: 868: 848: 828: 817:highest weight 802: 780: 760: 734: 731: 728: 708: 684: 675:, we say that 662: 656: 633: 613: 588: 582: 576: 573: 551: 547: 543: 540: 520: 517: 514: 511: 508: 505: 502: 476: 470: 464: 461: 439: 435: 414: 403: 402: 388: 385: 382: 379: 376: 371: 368: 365: 362: 359: 353: 324: 318: 312: 309: 285: 263: 236: 216: 213: 211: 208: 180: 160: 138: 125: 124: 113: 108: 104: 100: 97: 94: 71: 42: 13: 10: 9: 6: 4: 3: 2: 1967: 1956: 1953: 1951: 1948: 1946: 1943: 1941: 1938: 1937: 1935: 1924: 1918: 1913: 1912: 1906: 1902: 1899: 1893: 1889: 1884: 1880: 1876: 1872: 1868: 1864: 1858: 1854: 1850: 1846: 1842: 1838: 1834: 1830: 1827: 1823: 1819: 1813: 1809: 1805: 1801: 1800: 1794: 1793: 1789: 1781: 1776: 1773: 1769: 1764: 1761: 1757: 1752: 1749: 1745: 1740: 1737: 1733: 1728: 1725: 1721: 1716: 1713: 1708: 1704: 1700: 1696: 1692: 1688: 1684: 1677: 1674: 1670: 1665: 1663: 1659: 1655: 1650: 1648: 1644: 1640: 1635: 1632: 1625: 1621: 1618: 1616: 1613: 1611: 1608: 1607: 1603: 1597: 1593: 1589: 1585: 1582: 1581:Verma modules 1578: 1575: 1571: 1567: 1566: 1565: 1559: 1557: 1543: 1534: 1520: 1500: 1456: 1436: 1416: 1393: 1390: 1385: 1382: 1379: 1375: 1367: 1366: 1365: 1345: 1342: 1339: 1329: 1328: 1327: 1325: 1302: 1299: 1279: 1228: 1225: 1215: 1164: 1156: 1155:maximal torus 1140: 1089: 1086: 1076: 1037: 1021: 1011: 1003: 1001: 983: 963: 955: 952: 937: 893: 885: 884: 883: 880: 866: 846: 826: 818: 778: 758: 751: 746: 732: 729: 726: 706: 698: 682: 660: 631: 611: 603: 586: 574: 571: 564:. An element 549: 545: 541: 538: 518: 515: 509: 506: 503: 492: 474: 462: 459: 437: 433: 412: 383: 380: 377: 366: 363: 360: 351: 344: 343: 342: 340: 322: 310: 307: 299: 283: 252: 222: 214: 209: 207: 205: 201: 197: 192: 178: 158: 106: 102: 92: 85: 84: 83: 69: 62: 58: 31: 28:of a complex 27: 23: 19: 1945:Lie algebras 1910: 1887: 1840: 1798: 1775: 1763: 1751: 1739: 1727: 1715: 1690: 1686: 1676: 1671:Theorem 12.6 1639:Dixmier 1996 1634: 1563: 1535: 1408: 1363: 1323: 1013: 999: 881: 816: 747: 696: 601: 490: 404: 338: 224: 200:Hermann Weyl 193: 126: 21: 15: 1837:Harris, Joe 1734:Section 8.8 1722:Section 8.7 298:root system 196:Élie Cartan 1934:Categories 1790:References 1782:Chapter 12 1008:See also: 219:See also: 1907:(1972a), 1879:246650103 1780:Hall 2015 1768:Hall 2015 1756:Hall 2015 1744:Hall 2015 1732:Hall 2015 1720:Hall 2015 1669:Hall 2015 1654:Hall 2015 1383:π 1349:⟩ 1340:λ 1337:⟨ 1303:∈ 1300:λ 984:λ 964:λ 847:μ 827:λ 759:λ 733:μ 730:− 727:λ 707:μ 683:λ 661:∗ 632:μ 612:λ 587:∗ 575:∈ 572:λ 542:∈ 539:α 516:≥ 513:⟩ 510:α 504:λ 501:⟨ 475:∗ 463:∈ 460:λ 413:α 387:⟩ 384:α 378:α 375:⟨ 370:⟩ 367:α 361:λ 358:⟨ 323:∗ 311:∈ 308:λ 210:Statement 107:λ 96:↦ 93:λ 61:Lie group 1839:(1991). 1604:See also 1572:and the 1062:and let 531:for all 491:dominant 339:integral 1871:1153249 1826:0498740 1707:3647845 1599:groups. 1591:proof.) 1201:. Then 930:, then 644:are in 1919:  1894:  1877:  1869:  1859:  1824:  1814:  1705:  1560:Proofs 1409:where 1133:. Let 750:weight 697:higher 276:. Let 1703:JSTOR 1626:Notes 1153:be a 699:than 1917:ISBN 1892:ISBN 1875:OCLC 1857:ISBN 1812:ISBN 1594:The 1586:The 1326:if 1014:Let 624:and 341:if 225:Let 1849:doi 1695:doi 1691:110 1322:is 1157:in 886:If 859:of 819:if 791:of 719:if 695:is 493:if 489:is 337:is 151:or 16:In 1936:: 1873:. 1867:MR 1865:. 1855:. 1843:. 1835:; 1822:MR 1820:, 1810:, 1802:, 1701:. 1689:. 1685:. 1661:^ 1646:^ 1216::= 1077::= 879:. 748:A 206:. 1926:. 1881:. 1851:: 1709:. 1697:: 1576:. 1544:K 1521:K 1501:K 1479:g 1457:K 1437:K 1417:I 1394:I 1391:= 1386:H 1380:2 1376:e 1346:H 1343:, 1308:h 1280:R 1258:g 1234:t 1229:i 1226:+ 1221:t 1211:h 1187:t 1165:K 1141:T 1119:g 1095:k 1090:i 1087:+ 1082:k 1072:g 1048:k 1022:K 996:. 938:V 916:g 894:V 867:V 801:g 779:V 655:h 581:h 550:+ 546:R 519:0 507:, 469:h 438:+ 434:R 381:, 364:, 352:2 317:h 284:R 262:h 235:g 179:K 159:K 137:g 112:] 103:V 99:[ 70:K 41:g

Index

representation theory
irreducible representations
semisimple Lie algebra
irreducible representations
Lie group
Élie Cartan
Hermann Weyl
representation theory of semisimple Lie algebras
Weight (representation theory) § Weights in the representation theory of semisimple Lie algebras
Cartan subalgebra
root system
weight
Compact group § Representation theory of a connected compact Lie group
compact Lie group
maximal torus
Weyl character formula
Peter–Weyl theorem
Verma modules
Borel–Weil–Bott theorem
invariant theoretic
Classifying finite-dimensional representations of Lie algebras
Representation theory of a connected compact Lie group
Weights in the representation theory of semisimple Lie algebras
Dixmier 1996


Hall 2015


Hall 2015

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