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Mumford–Tate group

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482:
has shown that the dimension bounds the transcendence degree; so that the Mumford–Tate group catches sufficiently many algebraic relations between the periods. This is a special case of the full Grothendieck period conjecture.
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consisting of the integral cohomology classes. Not quite so much is needed for the definition of the Mumford–Tate group, but it does assume that the vector space
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of the Galois image. This conjecture is known only in particular cases. Through generalisations of this conjecture, the Mumford–Tate group has been connected to the
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used to describe Hodge structures has a concrete matrix representation, as the 2×2 invertible matrices of the shape that is given by the action of
478:, in the sense of the field generated by its entries, predicted by the dimension of its Mumford–Tate group, as in the previous section. Work of 155: 595: 351:(1), from the complex field to the real field, an algebraic torus whose character group consists of the two homomorphisms to 564: 647: 527: 240:
underlying the Hodge structure has a given rational structure, i.e. is given over the rational numbers
670: 106: 582:(1967), "Sur les groupes de Galois attachés aux groupes p-divisibles", in Springer, Tonny A. (ed.), 455: 58: 233: 665: 561:
Algebraic Groups and Discontinuous Subgroups (Proc. Sympos. Pure Math., Boulder, Colo., 1965)
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The original context for the formulation of the group in question was the question of the
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Mumford-Tate groups, families of Calabi-Yau varieties and analogue André-Oort problems I
20: 229: 642: 591: 579: 114: 341: 225: 78: 511: 621: 617: 601: 587: 568: 416: 70: 62: 47: 40: 479: 90: 305:. Thinking of the matrix in terms of the complex number λ it represents, 659: 556: 467: 215: 82: 74: 612:
Tate, John T. (1967), "p-divisible groups.", in Springer, Tonny A. (ed.),
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of the Hodge structure describes the action of the diagonal matrices of
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Once formulated in this fashion, the rational representation ρ of
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http://math.cts.nthu.edu.tw/Mathematics/preprints/prep2005-6-002.pdf
204:{\displaystyle {\begin{bmatrix}a&b\\-b&a\end{bmatrix}}.} 423: 584:
Proceedings of a Conference on Local Fields (Driebergen, 1966)
395:) is by definition the smallest algebraic group defined over 466:
A related conjecture on abelian varieties states that the
244:. For the purposes of the theory the complex vector space 500:
http://www.math.columbia.edu/~thaddeus/seattle/voisin.pdf
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Hodge structures arising in geometry, for example on the
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th power and of the complex conjugate of λ by the
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The circle group inside this group of matrices is the
164: 158: 280:is supposed therefore to be homogeneous of weight 203: 657: 512:http://math.berkeley.edu/~ribet/Articles/mg.pdf 297:, complex conjugate in pairs under switching 101:-adic analogue of Mumford's construction for 614:Proc. Conf. Local Fields( Driebergen, 1966) 402: 355:(1), interchanged by complex conjugation. 89:) introduced Mumford–Tate groups over the 73:of the image in the representation of the 559:(1966), "Families of abelian varieties", 555: 253:, obtained by extending the scalars of 86: 658: 117:, and named them Mumford–Tate groups. 578: 94: 611: 461: 442:)), to the extent that knowledge of 434:(coming from the Hodge structure on 110: 426:Lie group for a given prime number 340:underlying the matrix group is the 13: 336:In more abstract terms, the torus 14: 682: 632: 540:https://arxiv.org/abs/0805.2569v1 309:has the action of λ by the 93:under the name of Hodge groups. 366:setting up the Hodge structure 533: 521: 505: 493: 120: 1: 565:American Mathematical Society 549: 370:determines the image ρ( 7: 317:th power. Here necessarily 10: 687: 456:Sato–Tate conjecture 293:breaks up into subspaces 141:} of the complex numbers 486: 403:Mumford–Tate conjecture 399:containing this image. 59:rational representation 474:over number field has 205: 409:Galois representation 206: 39:) constructed from a 639:Lecture slides (PDF) 616:, Berlin, New York: 590:, pp. 118–131, 586:, Berlin, New York: 567:, pp. 347–351, 563:, Providence, R.I.: 476:transcendence degree 452:motivic Galois group 346:multiplicative group 156: 125:The algebraic torus 105:, using the work of 65:, the definition of 16:Mathematics concept 580:Serre, Jean-Pierre 201: 192: 115:p-divisible groups 103:Hodge–Tate modules 25:Mumford–Tate group 21:algebraic geometry 643:Phillip Griffiths 597:978-3-540-03953-2 462:Period conjecture 458:(now a theorem). 226:cohomology groups 678: 671:Algebraic groups 651:, preprint (PDF) 628: 608: 575: 543: 537: 531: 525: 519: 509: 503: 502:, pp. 7–9. 497: 342:Weil restriction 230:Kähler manifolds 210: 208: 207: 202: 197: 196: 137:on the basis {1, 79:rational numbers 686: 685: 681: 680: 679: 677: 676: 675: 656: 655: 635: 618:Springer-Verlag 598: 588:Springer-Verlag 552: 547: 546: 538: 534: 526: 522: 510: 506: 498: 494: 489: 464: 446:determines the 417:abelian variety 405: 386: 292: 252: 191: 190: 185: 176: 175: 170: 160: 159: 157: 154: 153: 123: 97:introduced the 91:complex numbers 71:Zariski closure 63:algebraic torus 48:algebraic group 41:Hodge structure 17: 12: 11: 5: 684: 674: 673: 668: 654: 653: 645: 634: 633:External links 631: 630: 629: 609: 596: 576: 557:Mumford, David 551: 548: 545: 544: 532: 520: 504: 491: 490: 488: 485: 480:Pierre Deligne 463: 460: 404: 401: 382: 334: 333: 288: 248: 212: 211: 200: 195: 189: 186: 184: 181: 178: 177: 174: 171: 169: 166: 165: 163: 122: 119: 57:is given by a 15: 9: 6: 4: 3: 2: 683: 672: 669: 667: 664: 663: 661: 652: 650: 646: 644: 640: 637: 636: 627: 623: 619: 615: 610: 607: 603: 599: 593: 589: 585: 581: 577: 574: 570: 566: 562: 558: 554: 553: 541: 536: 529: 524: 517: 513: 508: 501: 496: 492: 484: 481: 477: 473: 469: 468:period matrix 459: 457: 453: 449: 445: 441: 437: 433: 429: 425: 421: 418: 414: 410: 400: 398: 394: 390: 385: 381: 377: 373: 369: 365: 361: 356: 354: 350: 347: 343: 339: 331: 327: 323: 320: 319: 318: 316: 312: 308: 304: 300: 296: 291: 287: 283: 279: 275: 271: 266: 264: 260: 256: 251: 247: 243: 239: 235: 231: 227: 222: 220: 217: 216:unitary group 198: 193: 187: 182: 179: 172: 167: 161: 152: 151: 150: 148: 144: 140: 136: 132: 128: 118: 116: 112: 108: 104: 100: 96: 92: 88: 84: 80: 76: 72: 68: 64: 60: 56: 52: 49: 46:is a certain 45: 42: 38: 34: 30: 26: 22: 666:Hodge theory 648: 613: 583: 560: 535: 523: 514:, survey by 507: 495: 471: 465: 443: 439: 435: 431: 427: 419: 406: 396: 392: 388: 383: 379: 375: 371: 367: 363: 359: 357: 352: 348: 337: 335: 329: 325: 321: 314: 310: 306: 302: 298: 294: 289: 285: 281: 277: 273: 269: 267: 262: 258: 254: 249: 245: 241: 237: 223: 218: 213: 146: 142: 138: 134: 130: 126: 124: 98: 95:Serre (1967) 75:circle group 66: 54: 50: 43: 36: 32: 28: 24: 18: 448:Lie algebra 413:Tate module 268:The weight 265:, is used. 121:Formulation 77:, over the 29:Hodge group 660:Categories 550:References 69:is as the 516:Ken Ribet 232:, have a 180:− 374:(1)) in 626:0231827 606:0242839 573:0206003 542:, p. 7. 530:, p. 3. 411:on the 387:); and 344:of the 234:lattice 109: ( 85: ( 83:Mumford 53:. When 624:  604:  594:  571:  424:l-adic 415:of an 276:, and 61:of an 23:, the 487:Notes 257:from 221:(1). 145:over 113:) on 592:ISBN 301:and 111:1967 107:Tate 87:1966 27:(or 641:by 470:of 362:on 261:to 228:of 81:. 19:In 662:: 622:MR 620:, 602:MR 600:, 569:MR 389:MT 376:GL 353:GL 349:GL 328:= 324:+ 149:: 135:bi 33:MT 31:) 518:. 472:A 444:G 440:A 438:( 436:H 432:G 428:l 420:A 397:Q 393:F 391:( 384:C 380:V 378:( 372:U 368:F 364:V 360:T 338:T 332:. 330:k 326:q 322:p 315:q 311:p 307:V 303:q 299:p 295:V 290:C 286:V 282:k 278:V 274:T 270:k 263:C 259:Q 255:V 250:C 246:V 242:Q 238:V 219:U 199:. 194:] 188:a 183:b 173:b 168:a 162:[ 147:R 143:C 139:i 133:+ 131:a 127:T 99:p 67:G 55:F 51:G 44:F 37:F 35:(

Index

algebraic geometry
Hodge structure
algebraic group
rational representation
algebraic torus
Zariski closure
circle group
rational numbers
Mumford
1966
complex numbers
Serre (1967)
Hodge–Tate modules
Tate
1967
p-divisible groups
unitary group
cohomology groups
Kähler manifolds
lattice
Weil restriction
multiplicative group
Galois representation
Tate module
abelian variety
l-adic
Lie algebra
motivic Galois group
Sato–Tate conjecture
period matrix

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