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Talk:Iwahori–Hecke algebra

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383:. As I indicated above, it's possible to move the Iwahori-Hecke algebras to a separate article, but it won't completely solve the problem because of the ambiguity of the current use in representation theory. Other algebras that you mention fall under "Hecke algebras of locally compact groups" and do not need separate articles, with the exception of Hecke algebra of a Lie group. The latter is a fairly peculiar construction, and not very popular at the moment, except in the proof of Flath's theorem on automorphic representations. My natural reaction would be to make a separate article for it (if appropriate), but not worry about it here, except a 84: 74: 53: 369:, and the Hecke algebra of K-finite distributions supported on a maximal compact subgroup K of a semisimple group, and there are some other minor uses such as the double coset algebras of a finite index subgroup of a group, or the algebras giving the decomposition of induced representations. All closely related, but sufficiently different to have their own articles. If you dont want to move it the article will need a lot of dablinks at the top. 22: 350:
One possible solution is to keep the Hecke algebras of locally compact groups on this page and move the bulk of the article to "Iwahori-Hecke algebra". What other uses of "Hecke algebra" were you thinking of? My impression is that although, contrary to Lusztig's prediction quoted in the article, the
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The literature on Hecke algebras is enormous, just important contributions from Lusztig count in more than 20 papers. This is why I left the reference to Lusztig's paper establishing the isomorphism with the group algebra of W in the comments. My favorite list of references will include many more,
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I feel that it is important (although, admittedly difficult) to maintain a balance between accuracy of the statements and encyclopaedic nature of the article. Obviously, we don't want to make incorrect claims, as I accidentally had done earlier (forgot characteristic 0!) and was corrected by
214:. On the other hand, even for a representation theorist there are many subtle points in the theory, and sometimes it's best to just make a correct statement and not delve too much into the fine points. Maybe even that is excessive: for the case at hand, the important thing is that for 517: 140: 623: 664: 340:
Given the number of different uses of "Hecke algebra", it might be worth moving this article to (say) Iwahori–Hecke algebra, and using this page to link to the other uses.
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at the start of the definitions altogether. The problem arises again in the fifth listed property of Iwahori-Hecke algebras, because here the
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clearly have to be indeterminates for this to be true in the stated generality (i.e. without explicitly excluding some roots of unity).
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term Iwahori-Hecke algebra is becoming more widespread, there is still a significant body of literature that refers to them simply as
97: 58: 174:? I feel like two different definitions got mixed up in this. In the following definition of the multiparameter algebras the 33: 302:
Lusztig gave in non-modular cases an explicit isomorphism between generic Hecke algebra and the group algebra of
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I don't know enough about Hecke algebras of modular forms to determine if they merit an article separate from
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and I seem to remember that one half is only necessary for exceptional cases, maybe even only in type
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on Knowledge. If you would like to participate, please visit the project page, where you can join
628: 89: 73: 52: 669: 322:. If you want to discuss roots of unity, go ahead and write a separate section (or article)! 233: 548: 522: 727: 571:
of two bi-invariant functions is left-invariant (using a left-invariant Haar measure), but
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link. I am going to write a separate article on affine Hecke algebras soon.
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I am not quite happy with the way the definition starts out: Are the
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becomes a particular number) of Hecke algebra is isomorphic to
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being unimodular. Feel free to undo this, if I'm wrong here.
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Note that this is a lot weaker result than saying that the
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The main other uses are the Hecke algebras generated by
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Hecke algebra is isomorphic to the group algebra of
101:, a collaborative effort to improve the coverage of 710: 687: 658: 617: 563: 537: 511: 290: 260: 402:If I see this correctly then the statement that 170:or are they supposed to be indeterminates over 182:so maybe one should remove the definition of 8: 506: 409: 205:Benson-Curtis theorem and issues of accuracy 19: 47: 703: 671: 630: 603: 576: 550: 524: 437: 422: 407: 326:but is hardly appropriate for Knowledge. 279: 273: 245: 241: 235: 698:Therefore I'm adding the requirement of 230:over the field of rational functions in 49: 7: 95:This article is within the scope of 519:is a algebra under convolution, if 38:It is of interest to the following 673: 618:{\displaystyle (f\ast g)(xh^{-1})} 442: 398:The case of locally compact groups 14: 747:Low-priority mathematics articles 298:Thus it may suffice to say that 115:Knowledge:WikiProject Mathematics 742:Start-Class mathematics articles 695:if my calculations are correct. 118:Template:WikiProject Mathematics 82: 72: 51: 20: 135:This article has been rated as 682: 676: 653: 647: 644: 632: 612: 593: 590: 578: 503: 497: 488: 471: 438: 434: 428: 1: 109:and see a list of open tasks. 728:13:28, 2 December 2010 (UTC) 659:{\displaystyle (f\ast g)(x)} 200:15:09, 24 August 2017 (UTC) 763: 688:{\displaystyle \Delta (h)} 392:03:08, 27 March 2007 (UTC) 374:02:20, 27 March 2007 (UTC) 360:01:44, 27 March 2007 (UTC) 345:00:38, 27 March 2007 (UTC) 331:02:42, 26 March 2007 (UTC) 134: 67: 46: 261:{\displaystyle q^{1/2},} 141:project's priority scale 564:{\displaystyle f\ast g} 538:{\displaystyle H\leq G} 178:are indeed elements of 98:WikiProject Mathematics 712: 689: 660: 619: 565: 539: 513: 292: 291:{\displaystyle E_{8}.} 262: 166:elements of some ring 28:This article is rated 713: 690: 661: 620: 566: 540: 514: 293: 263: 702: 670: 629: 575: 549: 523: 406: 272: 234: 121:mathematics articles 708: 685: 656: 615: 561: 535: 509: 288: 258: 90:Mathematics portal 34:content assessment 711:{\displaystyle G} 155: 154: 151: 150: 147: 146: 754: 717: 715: 714: 709: 694: 692: 691: 686: 665: 663: 662: 657: 624: 622: 621: 616: 611: 610: 570: 568: 567: 562: 544: 542: 541: 536: 518: 516: 515: 510: 487: 458: 441: 427: 426: 297: 295: 294: 289: 284: 283: 267: 265: 264: 259: 254: 253: 249: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 16: 762: 761: 757: 756: 755: 753: 752: 751: 732: 731: 700: 699: 668: 667: 627: 626: 599: 573: 572: 547: 546: 521: 520: 480: 451: 418: 404: 403: 400: 381:Hecke operators 367:Hecke operators 338: 275: 270: 269: 237: 232: 231: 207: 160: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 760: 758: 750: 749: 744: 734: 733: 707: 684: 681: 678: 675: 655: 652: 649: 646: 643: 640: 637: 634: 614: 609: 606: 602: 598: 595: 592: 589: 586: 583: 580: 560: 557: 554: 534: 531: 528: 508: 505: 502: 499: 496: 493: 490: 486: 483: 479: 476: 473: 470: 467: 464: 461: 457: 454: 450: 447: 444: 440: 436: 433: 430: 425: 421: 417: 414: 411: 399: 396: 395: 394: 363: 362: 353:Hecke algebras 337: 334: 312:specialization 308: 307: 287: 282: 278: 257: 252: 248: 244: 240: 212:76.201.143.150 206: 203: 192:134.61.173.178 159: 156: 153: 152: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 759: 748: 745: 743: 740: 739: 737: 730: 729: 725: 721: 720:141.35.40.141 705: 696: 679: 650: 641: 638: 635: 625:differs from 607: 604: 600: 596: 587: 584: 581: 558: 555: 552: 532: 529: 526: 500: 494: 491: 484: 481: 477: 474: 468: 465: 462: 459: 455: 452: 448: 445: 431: 423: 419: 415: 412: 397: 393: 390: 386: 382: 378: 377: 376: 375: 372: 368: 361: 358: 354: 349: 348: 347: 346: 343: 335: 333: 332: 329: 323: 321: 317: 313: 305: 301: 300: 299: 285: 280: 276: 255: 250: 246: 242: 238: 229: 225: 221: 217: 213: 204: 202: 201: 197: 193: 189: 185: 181: 177: 173: 169: 165: 157: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 23: 18: 17: 697: 401: 384: 364: 352: 339: 324: 319: 315: 311: 309: 303: 227: 223: 219: 215: 208: 187: 183: 179: 175: 171: 167: 163: 161: 137:Low-priority 136: 96: 62:Low‑priority 40:WikiProjects 112:Mathematics 103:mathematics 59:Mathematics 30:Start-class 736:Categories 158:Definition 385:see also 224:generic 139:on the 389:Arcfrk 371:R.e.b. 357:Arcfrk 342:R.e.b. 328:Arcfrk 222:, the 36:scale. 336:Move? 724:talk 196:talk 666:by 188:q_s 176:q_s 164:q_s 131:Low 738:: 726:) 674:Δ 639:∗ 605:− 585:∗ 556:∗ 530:≤ 460:∈ 443:∀ 416:∈ 198:) 722:( 706:G 683:) 680:h 677:( 654:) 651:x 648:( 645:) 642:g 636:f 633:( 613:) 608:1 601:h 597:x 594:( 591:) 588:g 582:f 579:( 559:g 553:f 533:G 527:H 507:} 504:) 501:x 498:( 495:f 492:= 489:) 485:′ 482:h 478:x 475:h 472:( 469:f 466:: 463:H 456:′ 453:h 449:, 446:h 439:| 435:) 432:G 429:( 424:c 420:C 413:f 410:{ 320:Q 316:q 314:( 306:. 304:W 286:. 281:8 277:E 256:, 251:2 247:/ 243:1 239:q 228:W 220:Q 218:= 216:R 194:( 184:A 180:R 172:Z 168:R 143:. 42::

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the discussion
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134.61.173.178
talk
15:09, 24 August 2017 (UTC)
76.201.143.150
Arcfrk
02:42, 26 March 2007 (UTC)
R.e.b.
00:38, 27 March 2007 (UTC)
Arcfrk
01:44, 27 March 2007 (UTC)
Hecke operators
R.e.b.
02:20, 27 March 2007 (UTC)
Hecke operators
Arcfrk
03:08, 27 March 2007 (UTC)
141.35.40.141

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