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Kazhdan–Lusztig polynomial

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2765: 1617: 2223: 1964: 1272: 2760:{\displaystyle {\begin{aligned}152q^{22}&+3,472q^{21}+38,791q^{20}+293,021q^{19}+1,370,892q^{18}+4,067,059q^{17}+7,964,012q^{16}\\&+11,159,003q^{15}+11,808,808q^{14}+9,859,915q^{13}+6,778,956q^{12}+3,964,369q^{11}+2,015,441q^{10}\\&+906,567q^{9}+363,611q^{8}+129,820q^{7}+41,239q^{6}+11,426q^{5}+2,677q^{4}+492q^{3}+61q^{2}+3q\end{aligned}}} 627: 166:). The representation had two natural bases, and the transition matrix between these two bases is essentially given by the Kazhdan–Lusztig polynomials. The actual Kazhdan–Lusztig construction of their polynomials is more elementary. Kazhdan and Lusztig used this to construct a canonical basis in the 3538:
was already known from the interpretation of coefficients of the Kazhdan–Lusztig polynomials as the dimensions of intersection cohomology groups, irrespective of the conjectures. Conversely, the relation between Kazhdan–Lusztig polynomials and the Ext groups theoretically can be used to prove the
1612:{\displaystyle R_{x,y}={\begin{cases}0,&{\mbox{if }}x\not \leq y\\1,&{\mbox{if }}x=y\\R_{sx,sy},&{\mbox{if }}sx<x{\mbox{ and }}sy<y\\R_{xs,ys},&{\mbox{if }}xs<x{\mbox{ and }}ys<y\\(q-1)R_{sx,y}+qR_{sx,sy},&{\mbox{if }}sx>x{\mbox{ and }}sy<y\end{cases}}} 4152:
Combinatorial properties of Kazhdan–Lusztig polynomials and their generalizations are a topic of active current research. Given their significance in representation theory and algebraic geometry, attempts have been undertaken to develop the theory of Kazhdan–Lusztig polynomials in purely
1628: 1981:. These formulas are tiresome to use by hand for rank greater than about 3, but are well adapted for computers, and the only limit on computing Kazhdan–Lusztig polynomials with them is that for large rank the number of such polynomials exceeds the storage capacity of computers. 4123:
are all tightly controlled by appropriate analogues of Kazhdan–Lusztig polynomials. They admit an elementary description, but the deeper properties of these polynomials necessary for representation theory follow from sophisticated techniques of modern algebraic geometry and
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are determined in terms of coefficients of Kazhdan–Lusztig polynomials. This result demonstrates that all coefficients of the Kazhdan–Lusztig polynomials of a finite Weyl group are non-negative integers. However, positivity for the case of a finite Weyl group
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The coefficients of the Kazhdan–Lusztig polynomials are conjectured to be the dimensions of some homomorphism spaces in Soergel's bimodule category. This is the only known positive interpretation of these coefficients for arbitrary Coxeter groups.
3181: 3479: 426: 3832: 1004: 1959:{\displaystyle q^{{\frac {1}{2}}(\ell (w)-\ell (x))}D(P_{x,w})-q^{{\frac {1}{2}}(\ell (x)-\ell (w))}P_{x,w}=\sum _{x<y\leq w}(-1)^{\ell (x)+\ell (y)}q^{{\frac {1}{2}}(-\ell (x)+2\ell (y)-\ell (w))}D(R_{x,y})P_{y,w}} 1261: 4103:. Much of the later work of Lusztig explored analogues of Kazhdan–Lusztig polynomials in the context of other natural singular algebraic varieties arising in representation theory, in particular, closures of 2228: 431: 4441: 2912: 805: 4153:
combinatorial fashion, relying to some extent on geometry, but without reference to intersection cohomology and other advanced techniques. This has led to exciting developments in
3689:, and Kazhdan and Lusztig, following a suggestion of Deligne, showed how to express Kazhdan–Lusztig polynomials in terms of intersection cohomology groups of Schubert varieties. 622:{\displaystyle {\begin{aligned}T_{y}T_{w}&=T_{yw},&&{\mbox{if }}\ell (yw)=\ell (y)+\ell (w)\\(T_{s}+1)(T_{s}-q)&=0,&&{\mbox{if }}s\in S.\end{aligned}}} 4070: 3969: 3061: 2789:
paper also put forth two equivalent conjectures, known now as Kazhdan–Lusztig conjectures, which related the values of their polynomials at 1 with representations of complex
4345: 3332: 1112: 418: 4274: 3624: 2776:
showed that any polynomial with constant term 1 and non-negative integer coefficients is the Kazhdan–Lusztig polynomial for some pair of elements of some symmetric group.
1042: 74: 275: 4300: 348: 4233: 322: 150: 5066: 4201: 4365: 3274:. Thus, the Kazhdan–Lusztig conjectures describe the Jordan–Hölder multiplicities of Verma modules in any regular integral block of Bernstein–Gelfand–Gelfand 5061: 3715: 4602: 3222:). The methods introduced in the course of the proof have guided development of representation theory throughout the 1980s and 1990s, under the name 903: 2206:
The simple values of Kazhdan–Lusztig polynomials for low rank groups are not typical of higher rank groups. For example, for the split form of E
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The Kazhdan–Lusztig polynomials arise as transition coefficients between their canonical basis and the natural basis of the Hecke algebra. The
1118:
To establish existence of the Kazhdan–Lusztig polynomials, Kazhdan and Lusztig gave a simple recursive procedure for computing the polynomials
4586: 1148: 2069: 3904:. Their definition is more complicated, reflecting relative complexity of representations of real groups compared to complex groups. 4812: 4556: 194: 4095:
The second paper of Kazhdan and Lusztig established a geometric setting for definition of Kazhdan–Lusztig polynomials, namely, the
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This gave the first proof that all coefficients of Kazhdan–Lusztig polynomials for finite Weyl groups are non-negative integers.
290: 167: 4137: 3235: 4796: 2850: 229: 3050:{\displaystyle \operatorname {ch} (L_{w})=\sum _{y\leq w}(-1)^{\ell (w)-\ell (y)}P_{y,w}(1)\operatorname {ch} (M_{y})} 221: 4370: 5071: 4831: 4703: 4625: 4002: 173:
In their first paper Kazhdan and Lusztig mentioned that their polynomials were related to the failure of local
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Soergel, Wolfgang (2006), "Kazhdan–Lusztig polynomials and indecomposable bimodules over polynomial rings",
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In March 2007, a collaborative project, the "Atlas of Lie groups and representations", announced that the
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The distinction, in the cases directly connection to representation theory, is explained on the level of
3630: 3838: 3176:{\displaystyle \operatorname {ch} (M_{w})=\sum _{y\leq w}P_{w_{0}w,w_{0}y}(1)\operatorname {ch} (L_{y})} 28: 3474:{\displaystyle P_{y,w}(q)=\sum _{i}q^{i}\dim(\operatorname {Ext} ^{\ell (w)-\ell (y)-2i}(M_{y},L_{w}))} 4108: 5056: 4844: 4716: 4638: 4120: 4041: 3976: 3940: 3642: 2790: 217: 4305: 1300: 204:
The two bases for the Springer representation reminded Kazhdan and Lusztig of the two bases for the
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Polo, Patrick (1999), "Construction of arbitrary Kazhdan–Lusztig polynomials in symmetric groups",
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conjectures, although this approach to proving them turned out to be more difficult to carry out.
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These conjectures were proved over characteristic 0 algebraically closed fields independently by
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5. Kashiwara (1990) proved a generalization of the Kazhdan–Lusztig conjectures to symmetrizable
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Kobayashi, Masato (2013), "Inequalities on Bruhat graphs, R- and Kazhdan-Lusztig polynomials",
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where each term on the right means: take the complex IC of sheaves whose hyperhomology is the
251: 5003: 4975: 4936: 4889: 4852: 4800: 4770: 4724: 4674: 4646: 4620: 4527: 4510: 4279: 4133: 4077: 4022: 4012: 3896:. They are analogous to Kazhdan–Lusztig polynomials, but are tailored to representations of 3874:. The odd-dimensional cohomology groups do not appear in the sum because they are all zero. 3842: 3312: 3215: 3203: 1017: 327: 178: 4909: 4686: 4489: 4206: 300: 135: 4905: 4840: 4712: 4682: 4634: 4485: 4104: 3542:
4. Some special cases of the Kazhdan–Lusztig conjectures are easy to verify. For example,
225: 155: 128: 4597: 4180: 3567:= 1, since the sum reduces to a single term. On the other hand, the first conjecture for 4848: 4720: 4642: 17: 4822: 4788: 4756: 4698: 4350: 4112: 3931: 711: 81: 5050: 4989: 4948: 4872: 4784: 4775: 4752: 4744: 4694: 4544: 3980: 3912: 3303:
in certain subquotient of the Verma module determined by a canonical filtration, the
1978: 213: 208:
of certain infinite dimensional representations of semisimple Lie algebras, given by
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The Kazhdan–Lusztig polynomials can then be computed recursively using the relation
197:, and gave another definition of such a basis in terms of the dimensions of certain 5014: 4100: 3984: 3908: 3901: 3900:
semisimple Lie groups, and play major role in the conjectural description of their
2820: 852: 209: 190: 162:. They found a new construction of these representations over the complex numbers ( 4893: 3863:, and then take the dimension of the stalk of this sheaf at any point of the cell 3827:{\displaystyle P_{y,w}(q)=\sum _{i}q^{i}\dim IH_{X_{y}}^{2i}({\overline {X_{w}}})} 4804: 3307:. The Jantzen conjecture in regular integral case was proved in a later paper of 4826: 4540: 3323: 2839: 5018: 4980: 4681:, Progress in Mathematics, vol. 87, Boston: Birkhauser, pp. 407–433, 3549:
is the antidominant Verma module, which is known to be simple. This means that
5007: 4940: 4677:(1990), "The Kazhdan–Lusztig conjecture for symmetrizable KacMoody algebras", 4598:"Kazhdan–Lusztig Polynomials: History, Problems, and Combinatorial Invariance" 3526: 3275: 2805: 124: 104: 4901: 4864: 4736: 4658: 3988: 999:{\displaystyle C'_{w}=q^{-{\frac {\ell (w)}{2}}}\sum _{y\leq w}P_{y,w}T_{y}} 232:
to representations of Weyl groups, led to the Kazhdan–Lusztig conjectures.
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for crystallographic Coxeter groups satisfy certain strict inequality: Let
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are locally-finite weight modules over the complex semisimple Lie algebra
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software for computing Kazhdan–Lusztig polynomials for any Coxeter group
5026: 4856: 4728: 4650: 5040: 4517:, Sér. I Math., vol. 292, Paris: C. R. Acad. Sci., pp. 15–18 4177:
Kobayashi (2013) proved that values of Kazhdan–Lusztig polynomials at
1256:{\displaystyle T_{y^{-1}}^{-1}=\sum _{x}D(R_{x,y})q^{-\ell (x)}T_{x}.} 4931: 4701:(June 1979), "Representations of Coxeter groups and Hecke algebras", 2211: 4829:(1983), "Singularities of closures of K-orbits on flag manifolds.", 4623:(October 1981), "Kazhdan–Lusztig conjecture and holonomic systems", 3934:. The original (K-L) case is then about the details of decomposing 4970: 4551:, Progress in Mathematics, vol. 182, Boston, MA: Birkhäuser, 714:. From this it follows that the Hecke algebra has an automorphism 4759:(1980a), "A topological approach to Springer's representations", 1969:
using the fact that the two terms on the left are polynomials in
4795:, Proceedings of Symposia in Pure Mathematics, vol. XXXVI, 2797:, addressing a long-standing problem in representation theory. 3586:, together with the fact that all Kazhdan–Lusztig polynomials 2110:(or more generally any Coxeter group of rank at most 2) then 76:
is a member of a family of integral polynomials introduced by
4534:, Advances in Soviet Mathematics, vol. 16, pp. 1–50 3285:
coefficients of Kazhdan–Lusztig polynomials follows from the
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1. The two conjectures are known to be equivalent. Moreover,
4048: 3947: 1605: 2214:(a variation of Kazhdan–Lusztig polynomials: see below) is 632:
The quadratic second relation implies that each generator
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Relation to intersection cohomology of Schubert varieties
4569:; Brenti, Francesco (2005), "Ch. 5: Kazhdan–Lusztig and 4091:
Generalization to other objects in representation theory
839:, and uniquely determined by the following properties. 119:
In the spring of 1978 Kazhdan and Lusztig were studying
4462:"Computing Kazhdan-Lusztig-Vogan polynomials for split 3911:; or in other terms of actions on analogues of complex 1584: 1565: 1475: 1456: 1406: 1387: 1340: 1312: 597: 481: 5006:
from Spring 2005 course on Kazhdan–Lusztig Theory at
4373: 4353: 4308: 4282: 4241: 4209: 4183: 4044: 3943: 3718: 3592: 3335: 3289:, which roughly says that individual coefficients of 3064: 2915: 2226: 1631: 1275: 1151: 1050: 1020: 906: 746: 429: 356: 330: 303: 254: 138: 40: 4610:, Ellwangen: Haus Schönenberg: Research article B49b 3195:
is the element of maximal length of the Weyl group.
693:(obtained by multiplying the quadratic relation for 1266:They can be computed using the recursion relations 4919:Journal of the Institute of Mathematics of Jussieu 4435: 4359: 4339: 4294: 4268: 4227: 4195: 4111:. It turned out that the representation theory of 4064: 3963: 3826: 3618: 3473: 3316: 3219: 3207: 3175: 3049: 2759: 1958: 1611: 1255: 1129:) in terms of more elementary polynomials denoted 1106: 1036: 998: 799: 621: 412: 342: 316: 269: 144: 68: 639:is invertible in the Hecke algebra, with inverse 5043:for computing Kazhdan–Lusztig-Vogan polynomials. 4577:, Graduate Texts in Mathematics, vol. 231, 4166: 3326:showed as a consequence of the conjectures that 4161:. Some references are given in the textbook of 3692:More precisely, the Kazhdan–Lusztig polynomial 182: 163: 4099:of singularities of Schubert varieties in the 2838:where ρ is the half-sum of positive roots (or 2203:, giving examples of non-constant polynomials. 85: 4436:{\displaystyle P_{uw}(1)>P_{tu,w}(1)>0} 4162: 8: 3893: 3888:(also called Kazhdan–Lusztig polynomials or 5029:for computing Kazhdan–Lusztig polynomials. 4235:be a crystallographic Coxeter system and 1114:-module, called the Kazhdan–Lusztig basis. 281:(the smallest length of an expression for 4979: 4969: 4958:Journal of Combinatorial Theory, Series A 4930: 4774: 4403: 4378: 4372: 4352: 4313: 4307: 4281: 4247: 4242: 4240: 4208: 4182: 4165:. A research monograph on the subject is 4138:Beilinson–Bernstein–Deligne decomposition 4054: 4043: 3953: 3942: 3870:whose closure is the Schubert variety of 3810: 3804: 3792: 3785: 3780: 3761: 3751: 3723: 3717: 3608: 3597: 3591: 3563:, establishing the second conjecture for 3459: 3446: 3397: 3378: 3368: 3340: 3334: 3164: 3131: 3115: 3110: 3094: 3078: 3063: 3038: 3004: 2970: 2945: 2929: 2914: 2906:. The Kazhdan–Lusztig conjectures state: 2738: 2722: 2706: 2684: 2662: 2640: 2618: 2596: 2567: 2539: 2511: 2483: 2455: 2427: 2392: 2364: 2336: 2308: 2286: 2264: 2238: 2227: 2225: 2212:most complicated Lusztig–Vogan polynomial 2070:longest element of a finite Coxeter group 1944: 1925: 1849: 1848: 1814: 1783: 1764: 1715: 1714: 1692: 1637: 1636: 1630: 1583: 1564: 1541: 1516: 1474: 1455: 1432: 1405: 1386: 1363: 1339: 1311: 1295: 1280: 1274: 1244: 1222: 1203: 1187: 1171: 1161: 1156: 1150: 1091: 1084: 1067: 1063: 1052: 1051: 1049: 1025: 1019: 990: 974: 958: 931: 927: 911: 905: 788: 778: 773: 757: 745: 596: 565: 543: 480: 465: 448: 438: 430: 428: 397: 390: 373: 369: 358: 357: 355: 329: 308: 302: 253: 137: 88:). They are indexed by pairs of elements 45: 39: 800:{\displaystyle D(T_{w})=T_{w^{-1}}^{-1}} 185:they reinterpreted this in terms of the 5019:"Tables of Kazhdan–Lusztig polynomials" 4793:Schubert varieties and Poincaré duality 4452: 4035:. Then the relevant object of study is 1044:form a basis of the Hecke algebra as a 4603:Séminaire Lotharingien de Combinatoire 3525:is odd, so the dimensions of all such 667:. These inverses satisfy the relation 5067:Representation theory of Lie algebras 3661:is a disjoint union of affine spaces 3236:Borho–Jantzen's translation principle 7: 4276:its Kazhdan–Lusztig polynomials. If 2773: 827:) are indexed by a pair of elements 5062:Representation theory of Lie groups 4549:Singular loci of Schubert varieties 4078:L–V polynomials had been calculated 1014:of the Hecke algebra. The elements 1010:are invariant under the involution 4532:A proof of the Jantzen conjectures 168:Hecke algebra of the Coxeter group 25: 4347:, then there exists a reflection 3890:Kazhdan–Lusztig–Vogan polynomials 3856:), take its cohomology of degree 3270:for any dominant integral weight 2849:be its irreducible quotient, the 811:can be seen to be an involution. 420:, with multiplication defined by 103:, which can in particular be the 4679:The Grothendieck Festschrift, II 814:The Kazhdan–Lusztig polynomials 216:. This analogy, and the work of 4575:Combinatorics of Coxeter Groups 4065:{\displaystyle K\backslash G/B} 3964:{\displaystyle B\backslash G/B} 3678:. The closures of these spaces 3281:2. A similar interpretation of 3224:geometric representation theory 4424: 4418: 4393: 4387: 4340:{\displaystyle P_{uw}(1)>1} 4328: 4322: 4262: 4256: 4222: 4210: 4167:Billey & Lakshmibai (2000) 3821: 3801: 3741: 3735: 3468: 3465: 3439: 3422: 3416: 3407: 3401: 3390: 3358: 3352: 3170: 3157: 3148: 3142: 3084: 3071: 3044: 3031: 3022: 3016: 2995: 2989: 2980: 2974: 2967: 2957: 2935: 2922: 1937: 1918: 1910: 1907: 1901: 1892: 1886: 1874: 1868: 1859: 1839: 1833: 1824: 1818: 1811: 1801: 1755: 1752: 1746: 1737: 1731: 1725: 1704: 1685: 1677: 1674: 1668: 1659: 1653: 1647: 1509: 1497: 1235: 1229: 1215: 1196: 1101: 1056: 943: 937: 763: 750: 577: 558: 555: 536: 529: 523: 514: 508: 499: 490: 407: 362: 264: 258: 63: 57: 1: 4894:10.1090/S1088-4165-99-00074-6 4797:American Mathematical Society 3881:Generalization to real groups 277:for the length of an element 183:Kazhdan & Lusztig (1980b) 27:In the mathematical field of 4776:10.1016/0001-8708(80)90005-5 4159:pattern-avoidance phenomenon 3816: 2851:simple highest weight module 1107:{\displaystyle \mathbb {Z} } 413:{\displaystyle \mathbb {Z} } 285:as a product of elements of 4478:Nieuw Archief voor Wiskunde 4269:{\displaystyle {P_{uw}(q)}} 4163:Björner & Brenti (2005) 3926:is a complex Lie group and 3619:{\displaystyle P_{y,w_{0}}} 3584:character of a Verma module 2781:Kazhdan–Lusztig conjectures 164:Kazhdan & Lusztig 1980a 5093: 4981:10.1016/j.jcta.2012.10.001 4596:Brenti, Francesco (2003), 4460:van Leeuwen, Marc (2008), 3894:Lusztig & Vogan (1983) 3670:parameterized by elements 69:{\displaystyle P_{y,w}(q)} 33:Kazhdan–Lusztig polynomial 4941:10.1017/S1474748007000023 4515:Localisation de g-modules 3975:a classical theme of the 3886:Lusztig–Vogan polynomials 3849:(the closure of the cell 2898:) for the character of a 2890:, and therefore admit an 875:their degree is at most ( 740:. More generally one has 170:and its representations. 4832:Inventiones Mathematicae 4805:10.1090/pspum/036/573434 4704:Inventiones Mathematicae 4626:Inventiones Mathematicae 4003:maximal compact subgroup 3582:and the formula for the 297:has a basis of elements 270:{\displaystyle \ell (w)} 121:Springer representations 18:Lusztig–Vogan polynomial 5077:Algebraic combinatorics 4762:Advances in Mathematics 4155:algebraic combinatorics 4130:intersection cohomology 3987:. The L-V case takes a 3653:of the algebraic group 3200:Alexander Beilinson 199:intersection cohomology 187:intersection cohomology 152:-adic cohomology groups 4437: 4361: 4341: 4296: 4295:{\displaystyle u<w} 4270: 4229: 4197: 4080:for the split form of 4066: 3965: 3828: 3620: 3580:Weyl character formula 3475: 3296:are multiplicities of 3212:Jean-Luc Brylinski 3177: 3051: 2761: 1960: 1613: 1257: 1108: 1038: 1037:{\displaystyle C'_{w}} 1000: 801: 623: 414: 344: 343:{\displaystyle w\in W} 318: 271: 146: 115:Motivation and history 70: 4882:Representation Theory 4438: 4362: 4342: 4297: 4271: 4230: 4228:{\displaystyle (W,S)} 4198: 4128:, such as the use of 4121:affine Hecke algebras 4067: 3979:, and before that of 3966: 3892:) were introduced in 3839:intersection homology 3829: 3621: 3476: 3178: 3052: 2791:semisimple Lie groups 2762: 2138:is the Coxeter group 2096:is the Coxeter group 1961: 1614: 1258: 1109: 1039: 1001: 802: 624: 415: 345: 319: 317:{\displaystyle T_{w}} 272: 147: 145:{\displaystyle \ell } 71: 29:representation theory 4799:, pp. 185–203, 4524:Beilinson, Alexandre 4507:Beilinson, Alexandre 4371: 4351: 4306: 4280: 4239: 4207: 4181: 4148:Combinatorial theory 4117:modular Lie algebras 4042: 3977:Bruhat decomposition 3941: 3716: 3643:Bruhat decomposition 3590: 3333: 3062: 2913: 2886:with the Weyl group 2224: 2145:with generating set 2011:has constant term 1. 1629: 1273: 1149: 1048: 1018: 904: 744: 427: 354: 328: 301: 252: 244:with generating set 240:Fix a Coxeter group 218:Jens Carsten Jantzen 136: 38: 4849:1983InMat..71..365L 4721:1979InMat..53..165K 4643:1981InMat..64..387B 4617:Brylinski, Jean-Luc 4196:{\displaystyle q=1} 4126:homological algebra 3800: 3252:can be replaced by 2894:. Let us write ch( 2892:algebraic character 1179: 1033: 919: 796: 230:enveloping algebras 5010:by Monica Vazirani 4857:10.1007/BF01389103 4729:10.1007/BF01390031 4651:10.1007/BF01389272 4433: 4357: 4337: 4292: 4266: 4225: 4193: 4062: 3961: 3824: 3776: 3756: 3687:Schubert varieties 3631:Kac–Moody algebras 3616: 3471: 3373: 3305:Jantzen filtration 3287:Jantzen conjecture 3173: 3105: 3047: 2956: 2853:of highest weight 2823:of highest weight 2757: 2755: 1956: 1800: 1609: 1604: 1588: 1569: 1479: 1460: 1410: 1391: 1344: 1316: 1253: 1192: 1152: 1104: 1034: 1021: 996: 969: 907: 843:They are 0 unless 797: 769: 619: 617: 601: 485: 410: 340: 314: 267: 206:Grothendieck group 179:Schubert varieties 142: 66: 5032:Fokko du Cloux's 4675:Kashiwara, Masaki 4621:Kashiwara, Masaki 4588:978-3-540-44238-7 4528:Bernstein, Joseph 4511:Bernstein, Joseph 4360:{\displaystyle t} 3819: 3747: 3578:follows from the 3364: 3090: 2941: 1857: 1779: 1723: 1645: 1587: 1568: 1478: 1459: 1409: 1390: 1343: 1315: 1183: 954: 950: 600: 484: 195:Robert MacPherson 156:conjugacy classes 78:David Kazhdan 16:(Redirected from 5084: 5072:Algebraic groups 5022: 4992: 4983: 4973: 4951: 4934: 4912: 4875: 4817: 4779: 4778: 4747: 4689: 4669: 4611: 4591: 4561: 4535: 4518: 4493: 4492: 4475: 4470: 4457: 4442: 4440: 4439: 4434: 4417: 4416: 4386: 4385: 4366: 4364: 4363: 4358: 4346: 4344: 4343: 4338: 4321: 4320: 4301: 4299: 4298: 4293: 4275: 4273: 4272: 4267: 4265: 4255: 4254: 4234: 4232: 4231: 4226: 4202: 4200: 4199: 4194: 4134:perverse sheaves 4109:quiver varieties 4105:nilpotent orbits 4071: 4069: 4068: 4063: 4058: 4034: 4023:complexification 4021:, and makes the 4020: 4013:semisimple group 4010: 3996: 3970: 3968: 3967: 3962: 3957: 3869: 3862: 3855: 3843:Schubert variety 3833: 3831: 3830: 3825: 3820: 3815: 3814: 3805: 3799: 3791: 3790: 3789: 3766: 3765: 3755: 3734: 3733: 3684: 3657:with Weyl group 3626:are equal to 1. 3625: 3623: 3622: 3617: 3615: 3614: 3613: 3612: 3524: 3501: 3480: 3478: 3477: 3472: 3464: 3463: 3451: 3450: 3435: 3434: 3383: 3382: 3372: 3351: 3350: 3302: 3295: 3273: 3269: 3251: 3216:Masaki Kashiwara 3204:Joseph Bernstein 3194: 3182: 3180: 3179: 3174: 3169: 3168: 3141: 3140: 3136: 3135: 3120: 3119: 3104: 3083: 3082: 3056: 3054: 3053: 3048: 3043: 3042: 3015: 3014: 2999: 2998: 2955: 2934: 2933: 2881: 2874: 2867: 2848: 2837: 2818: 2766: 2764: 2763: 2758: 2756: 2743: 2742: 2727: 2726: 2711: 2710: 2689: 2688: 2667: 2666: 2645: 2644: 2623: 2622: 2601: 2600: 2576: 2572: 2571: 2544: 2543: 2516: 2515: 2488: 2487: 2460: 2459: 2432: 2431: 2401: 2397: 2396: 2369: 2368: 2341: 2340: 2313: 2312: 2291: 2290: 2269: 2268: 2243: 2242: 2131:and 0 otherwise. 2040: 1965: 1963: 1962: 1957: 1955: 1954: 1936: 1935: 1914: 1913: 1858: 1850: 1843: 1842: 1799: 1775: 1774: 1759: 1758: 1724: 1716: 1703: 1702: 1681: 1680: 1646: 1638: 1618: 1616: 1615: 1610: 1608: 1607: 1589: 1585: 1570: 1566: 1558: 1557: 1530: 1529: 1480: 1476: 1461: 1457: 1449: 1448: 1411: 1407: 1392: 1388: 1380: 1379: 1345: 1341: 1317: 1313: 1291: 1290: 1262: 1260: 1259: 1254: 1249: 1248: 1239: 1238: 1214: 1213: 1191: 1178: 1170: 1169: 1168: 1113: 1111: 1110: 1105: 1100: 1099: 1095: 1076: 1075: 1071: 1055: 1043: 1041: 1040: 1035: 1029: 1005: 1003: 1002: 997: 995: 994: 985: 984: 968: 953: 952: 951: 946: 932: 915: 806: 804: 803: 798: 795: 787: 786: 785: 762: 761: 739: 732: 710:), and also the 706: 699: 692: 666: 638: 628: 626: 625: 620: 618: 602: 598: 594: 570: 569: 548: 547: 486: 482: 478: 473: 472: 453: 452: 443: 442: 419: 417: 416: 411: 406: 405: 401: 382: 381: 377: 361: 349: 347: 346: 341: 323: 321: 320: 315: 313: 312: 276: 274: 273: 268: 226:primitive ideals 175:Poincaré duality 151: 149: 148: 143: 75: 73: 72: 67: 56: 55: 21: 5092: 5091: 5087: 5086: 5085: 5083: 5082: 5081: 5047: 5046: 5013: 5000: 4955: 4916: 4879: 4841:Springer-Verlag 4823:Lusztig, George 4821: 4815: 4789:Lusztig, George 4783: 4757:Lusztig, George 4751: 4713:Springer-Verlag 4699:Lusztig, George 4693: 4673: 4635:Springer-Verlag 4615: 4595: 4589: 4567:Björner, Anders 4565: 4559: 4539: 4522: 4505: 4502: 4497: 4496: 4473: 4469: 4463: 4459: 4458: 4454: 4449: 4399: 4374: 4369: 4368: 4349: 4348: 4309: 4304: 4303: 4278: 4277: 4243: 4237: 4236: 4205: 4204: 4179: 4178: 4175: 4150: 4093: 4086: 4040: 4039: 4033: 4029: 4019: 4015: 4009: 4005: 3995: 3991: 3939: 3938: 3883: 3868: 3864: 3857: 3854: 3850: 3806: 3781: 3757: 3719: 3714: 3713: 3709:) is equal to 3704: 3683: 3679: 3669: 3639: 3604: 3593: 3588: 3587: 3577: 3562: 3555: 3548: 3503: 3498: 3491: 3485: 3455: 3442: 3393: 3374: 3336: 3331: 3330: 3301: 3297: 3294: 3290: 3271: 3253: 3239: 3232: 3193: 3187: 3160: 3127: 3111: 3106: 3074: 3060: 3059: 3034: 3000: 2966: 2925: 2911: 2910: 2880: 2876: 2873: 2869: 2854: 2847: 2843: 2824: 2817: 2813: 2808:. For each w ∈ 2783: 2754: 2753: 2734: 2718: 2702: 2680: 2658: 2636: 2614: 2592: 2574: 2573: 2563: 2535: 2507: 2479: 2451: 2423: 2399: 2398: 2388: 2360: 2332: 2304: 2282: 2260: 2244: 2234: 2222: 2221: 2209: 2198: 2181: 2169:commuting then 2144: 2122: 2109: 2102: 2084: 2067: 2053: 2023: 2010: 1987: 1940: 1921: 1844: 1810: 1760: 1710: 1688: 1632: 1627: 1626: 1603: 1602: 1586: and  1562: 1537: 1512: 1494: 1493: 1477: and  1453: 1428: 1425: 1424: 1408: and  1384: 1359: 1356: 1355: 1337: 1328: 1327: 1309: 1296: 1276: 1271: 1270: 1240: 1218: 1199: 1157: 1147: 1146: 1137: 1123: 1080: 1059: 1046: 1045: 1016: 1015: 986: 970: 933: 923: 902: 901: 822: 774: 753: 742: 741: 738: 734: 731: 727: 712:braid relations 705: 701: 698: 694: 686: 677: 668: 660: 648: 640: 637: 633: 616: 615: 593: 580: 561: 539: 533: 532: 477: 461: 454: 444: 434: 425: 424: 386: 365: 352: 351: 326: 325: 304: 299: 298: 250: 249: 238: 134: 133: 129:algebraic group 117: 41: 36: 35: 23: 22: 15: 12: 11: 5: 5090: 5088: 5080: 5079: 5074: 5069: 5064: 5059: 5049: 5048: 5045: 5044: 5037: 5030: 5023: 5011: 4999: 4998:External links 4996: 4995: 4994: 4964:(2): 470–482, 4953: 4925:(3): 501–525, 4914: 4877: 4819: 4813: 4785:Kazhdan, David 4781: 4769:(2): 222–228, 4753:Kazhdan, David 4749: 4695:Kazhdan, David 4691: 4671: 4613: 4593: 4587: 4573:polynomials", 4563: 4557: 4545:Lakshmibai, V. 4537: 4520: 4501: 4498: 4495: 4494: 4484:(2): 113–116, 4467: 4451: 4450: 4448: 4445: 4432: 4429: 4426: 4423: 4420: 4415: 4412: 4409: 4406: 4402: 4398: 4395: 4392: 4389: 4384: 4381: 4377: 4356: 4336: 4333: 4330: 4327: 4324: 4319: 4316: 4312: 4291: 4288: 4285: 4264: 4261: 4258: 4253: 4250: 4246: 4224: 4221: 4218: 4215: 4212: 4192: 4189: 4186: 4174: 4171: 4149: 4146: 4113:quantum groups 4092: 4089: 4084: 4074: 4073: 4061: 4057: 4053: 4050: 4047: 4031: 4017: 4007: 3993: 3981:Schubert cells 3973: 3972: 3960: 3956: 3952: 3949: 3946: 3932:Borel subgroup 3913:flag manifolds 3882: 3879: 3866: 3852: 3835: 3834: 3823: 3818: 3813: 3809: 3803: 3798: 3795: 3788: 3784: 3779: 3775: 3772: 3769: 3764: 3760: 3754: 3750: 3746: 3743: 3740: 3737: 3732: 3729: 3726: 3722: 3696: 3681: 3665: 3638: 3635: 3611: 3607: 3603: 3600: 3596: 3575: 3560: 3553: 3546: 3496: 3489: 3482: 3481: 3470: 3467: 3462: 3458: 3454: 3449: 3445: 3441: 3438: 3433: 3430: 3427: 3424: 3421: 3418: 3415: 3412: 3409: 3406: 3403: 3400: 3396: 3392: 3389: 3386: 3381: 3377: 3371: 3367: 3363: 3360: 3357: 3354: 3349: 3346: 3343: 3339: 3299: 3292: 3231: 3228: 3191: 3184: 3183: 3172: 3167: 3163: 3159: 3156: 3153: 3150: 3147: 3144: 3139: 3134: 3130: 3126: 3123: 3118: 3114: 3109: 3103: 3100: 3097: 3093: 3089: 3086: 3081: 3077: 3073: 3070: 3067: 3057: 3046: 3041: 3037: 3033: 3030: 3027: 3024: 3021: 3018: 3013: 3010: 3007: 3003: 2997: 2994: 2991: 2988: 2985: 2982: 2979: 2976: 2973: 2969: 2965: 2962: 2959: 2954: 2951: 2948: 2944: 2940: 2937: 2932: 2928: 2924: 2921: 2918: 2878: 2871: 2845: 2815: 2782: 2779: 2778: 2777: 2770: 2769: 2768: 2767: 2752: 2749: 2746: 2741: 2737: 2733: 2730: 2725: 2721: 2717: 2714: 2709: 2705: 2701: 2698: 2695: 2692: 2687: 2683: 2679: 2676: 2673: 2670: 2665: 2661: 2657: 2654: 2651: 2648: 2643: 2639: 2635: 2632: 2629: 2626: 2621: 2617: 2613: 2610: 2607: 2604: 2599: 2595: 2591: 2588: 2585: 2582: 2579: 2577: 2575: 2570: 2566: 2562: 2559: 2556: 2553: 2550: 2547: 2542: 2538: 2534: 2531: 2528: 2525: 2522: 2519: 2514: 2510: 2506: 2503: 2500: 2497: 2494: 2491: 2486: 2482: 2478: 2475: 2472: 2469: 2466: 2463: 2458: 2454: 2450: 2447: 2444: 2441: 2438: 2435: 2430: 2426: 2422: 2419: 2416: 2413: 2410: 2407: 2404: 2402: 2400: 2395: 2391: 2387: 2384: 2381: 2378: 2375: 2372: 2367: 2363: 2359: 2356: 2353: 2350: 2347: 2344: 2339: 2335: 2331: 2328: 2325: 2322: 2319: 2316: 2311: 2307: 2303: 2300: 2297: 2294: 2289: 2285: 2281: 2278: 2275: 2272: 2267: 2263: 2259: 2256: 2253: 2250: 2247: 2245: 2241: 2237: 2233: 2230: 2229: 2216: 2215: 2207: 2204: 2190: 2173: 2142: 2132: 2114: 2107: 2100: 2090: 2076: 2065: 2055: 2045: 2039:) ∈ {0, 1, 2} 2012: 2002: 1986: 1983: 1979:constant terms 1967: 1966: 1953: 1950: 1947: 1943: 1939: 1934: 1931: 1928: 1924: 1920: 1917: 1912: 1909: 1906: 1903: 1900: 1897: 1894: 1891: 1888: 1885: 1882: 1879: 1876: 1873: 1870: 1867: 1864: 1861: 1856: 1853: 1847: 1841: 1838: 1835: 1832: 1829: 1826: 1823: 1820: 1817: 1813: 1809: 1806: 1803: 1798: 1795: 1792: 1789: 1786: 1782: 1778: 1773: 1770: 1767: 1763: 1757: 1754: 1751: 1748: 1745: 1742: 1739: 1736: 1733: 1730: 1727: 1722: 1719: 1713: 1709: 1706: 1701: 1698: 1695: 1691: 1687: 1684: 1679: 1676: 1673: 1670: 1667: 1664: 1661: 1658: 1655: 1652: 1649: 1644: 1641: 1635: 1620: 1619: 1606: 1601: 1598: 1595: 1592: 1582: 1579: 1576: 1573: 1563: 1561: 1556: 1553: 1550: 1547: 1544: 1540: 1536: 1533: 1528: 1525: 1522: 1519: 1515: 1511: 1508: 1505: 1502: 1499: 1496: 1495: 1492: 1489: 1486: 1483: 1473: 1470: 1467: 1464: 1454: 1452: 1447: 1444: 1441: 1438: 1435: 1431: 1427: 1426: 1423: 1420: 1417: 1414: 1404: 1401: 1398: 1395: 1385: 1383: 1378: 1375: 1372: 1369: 1366: 1362: 1358: 1357: 1354: 1351: 1348: 1338: 1336: 1333: 1330: 1329: 1326: 1323: 1320: 1310: 1308: 1305: 1302: 1301: 1299: 1294: 1289: 1286: 1283: 1279: 1264: 1263: 1252: 1247: 1243: 1237: 1234: 1231: 1228: 1225: 1221: 1217: 1212: 1209: 1206: 1202: 1198: 1195: 1190: 1186: 1182: 1177: 1174: 1167: 1164: 1160: 1155: 1142:). defined by 1133: 1121: 1116: 1115: 1103: 1098: 1094: 1090: 1087: 1083: 1079: 1074: 1070: 1066: 1062: 1058: 1054: 1032: 1028: 1024: 1008: 1007: 1006: 993: 989: 983: 980: 977: 973: 967: 964: 961: 957: 949: 945: 942: 939: 936: 930: 926: 922: 918: 914: 910: 896: 895: 892: 818: 794: 791: 784: 781: 777: 772: 768: 765: 760: 756: 752: 749: 736: 729: 703: 696: 682: 673: 656: 644: 635: 630: 629: 614: 611: 608: 605: 595: 592: 589: 586: 583: 581: 579: 576: 573: 568: 564: 560: 557: 554: 551: 546: 542: 538: 535: 534: 531: 528: 525: 522: 519: 516: 513: 510: 507: 504: 501: 498: 495: 492: 489: 479: 476: 471: 468: 464: 460: 457: 455: 451: 447: 441: 437: 433: 432: 409: 404: 400: 396: 393: 389: 385: 380: 376: 372: 368: 364: 360: 350:over the ring 339: 336: 333: 311: 307: 266: 263: 260: 257: 237: 234: 222:Anthony Joseph 214:simple modules 141: 116: 113: 82:George Lusztig 65: 62: 59: 54: 51: 48: 44: 24: 14: 13: 10: 9: 6: 4: 3: 2: 5089: 5078: 5075: 5073: 5070: 5068: 5065: 5063: 5060: 5058: 5055: 5054: 5052: 5042: 5038: 5035: 5031: 5028: 5024: 5020: 5016: 5015:Goresky, Mark 5012: 5009: 5005: 5002: 5001: 4997: 4991: 4987: 4982: 4977: 4972: 4967: 4963: 4959: 4954: 4950: 4946: 4942: 4938: 4933: 4928: 4924: 4920: 4915: 4911: 4907: 4903: 4899: 4895: 4891: 4888:(4): 90–104, 4887: 4883: 4878: 4874: 4870: 4866: 4862: 4858: 4854: 4850: 4846: 4842: 4838: 4834: 4833: 4828: 4824: 4820: 4816: 4814:9780821814390 4810: 4806: 4802: 4798: 4794: 4790: 4786: 4782: 4777: 4772: 4768: 4764: 4763: 4758: 4754: 4750: 4746: 4742: 4738: 4734: 4730: 4726: 4722: 4718: 4714: 4710: 4706: 4705: 4700: 4696: 4692: 4688: 4684: 4680: 4676: 4672: 4668: 4664: 4660: 4656: 4652: 4648: 4644: 4640: 4636: 4632: 4628: 4627: 4622: 4618: 4614: 4609: 4605: 4604: 4599: 4594: 4590: 4584: 4580: 4576: 4572: 4568: 4564: 4560: 4558:0-8176-4092-4 4554: 4550: 4546: 4542: 4538: 4533: 4529: 4525: 4521: 4516: 4512: 4508: 4504: 4503: 4499: 4491: 4487: 4483: 4479: 4472: 4466: 4456: 4453: 4446: 4444: 4430: 4427: 4421: 4413: 4410: 4407: 4404: 4400: 4396: 4390: 4382: 4379: 4375: 4354: 4334: 4331: 4325: 4317: 4314: 4310: 4289: 4286: 4283: 4259: 4251: 4248: 4244: 4219: 4216: 4213: 4190: 4187: 4184: 4172: 4170: 4168: 4164: 4160: 4156: 4147: 4145: 4141: 4139: 4135: 4131: 4127: 4122: 4118: 4114: 4110: 4106: 4102: 4098: 4090: 4088: 4083: 4079: 4059: 4055: 4051: 4045: 4038: 4037: 4036: 4027: 4024: 4014: 4004: 4000: 3990: 3986: 3982: 3978: 3958: 3954: 3950: 3944: 3937: 3936: 3935: 3933: 3929: 3925: 3921: 3917: 3914: 3910: 3909:double cosets 3905: 3903: 3902:unitary duals 3899: 3895: 3891: 3887: 3880: 3878: 3875: 3873: 3861: 3848: 3844: 3840: 3811: 3807: 3796: 3793: 3786: 3782: 3777: 3773: 3770: 3767: 3762: 3758: 3752: 3748: 3744: 3738: 3730: 3727: 3724: 3720: 3712: 3711: 3710: 3708: 3703: 3699: 3695: 3690: 3688: 3677: 3673: 3668: 3664: 3660: 3656: 3652: 3648: 3644: 3636: 3634: 3632: 3627: 3609: 3605: 3601: 3598: 3594: 3585: 3581: 3574: 3570: 3566: 3559: 3552: 3545: 3540: 3537: 3532: 3528: 3522: 3518: 3514: 3510: 3506: 3499: 3492: 3460: 3456: 3452: 3447: 3443: 3436: 3431: 3428: 3425: 3419: 3413: 3410: 3404: 3398: 3394: 3387: 3384: 3379: 3375: 3369: 3365: 3361: 3355: 3347: 3344: 3341: 3337: 3329: 3328: 3327: 3325: 3320: 3318: 3314: 3311: and 3310: 3306: 3288: 3284: 3279: 3277: 3268: 3264: 3260: 3256: 3250: 3246: 3242: 3238:implies that 3237: 3229: 3227: 3225: 3221: 3217: 3214: and 3213: 3209: 3205: 3202: and 3201: 3196: 3190: 3165: 3161: 3154: 3151: 3145: 3137: 3132: 3128: 3124: 3121: 3116: 3112: 3107: 3101: 3098: 3095: 3091: 3087: 3079: 3075: 3068: 3065: 3058: 3039: 3035: 3028: 3025: 3019: 3011: 3008: 3005: 3001: 2992: 2986: 2983: 2977: 2971: 2963: 2960: 2952: 2949: 2946: 2942: 2938: 2930: 2926: 2919: 2916: 2909: 2908: 2907: 2905: 2901: 2897: 2893: 2889: 2885: 2866: 2862: 2858: 2852: 2841: 2836: 2832: 2828: 2822: 2811: 2807: 2803: 2798: 2796: 2792: 2788: 2780: 2775: 2772: 2771: 2750: 2747: 2744: 2739: 2735: 2731: 2728: 2723: 2719: 2715: 2712: 2707: 2703: 2699: 2696: 2693: 2690: 2685: 2681: 2677: 2674: 2671: 2668: 2663: 2659: 2655: 2652: 2649: 2646: 2641: 2637: 2633: 2630: 2627: 2624: 2619: 2615: 2611: 2608: 2605: 2602: 2597: 2593: 2589: 2586: 2583: 2580: 2578: 2568: 2564: 2560: 2557: 2554: 2551: 2548: 2545: 2540: 2536: 2532: 2529: 2526: 2523: 2520: 2517: 2512: 2508: 2504: 2501: 2498: 2495: 2492: 2489: 2484: 2480: 2476: 2473: 2470: 2467: 2464: 2461: 2456: 2452: 2448: 2445: 2442: 2439: 2436: 2433: 2428: 2424: 2420: 2417: 2414: 2411: 2408: 2405: 2403: 2393: 2389: 2385: 2382: 2379: 2376: 2373: 2370: 2365: 2361: 2357: 2354: 2351: 2348: 2345: 2342: 2337: 2333: 2329: 2326: 2323: 2320: 2317: 2314: 2309: 2305: 2301: 2298: 2295: 2292: 2287: 2283: 2279: 2276: 2273: 2270: 2265: 2261: 2257: 2254: 2251: 2248: 2246: 2239: 2235: 2231: 2220: 2219: 2218: 2217: 2213: 2205: 2202: 2197: 2193: 2189: 2185: 2180: 2176: 2172: 2168: 2164: 2160: 2156: 2152: 2148: 2141: 2137: 2133: 2130: 2126: 2121: 2117: 2113: 2106: 2099: 2095: 2091: 2088: 2083: 2079: 2075: 2071: 2064: 2060: 2056: 2052: 2048: 2044: 2038: 2034: 2030: 2026: 2021: 2017: 2013: 2009: 2005: 2001: 1997: 1993: 1989: 1988: 1984: 1982: 1980: 1976: 1972: 1951: 1948: 1945: 1941: 1932: 1929: 1926: 1922: 1915: 1904: 1898: 1895: 1889: 1883: 1880: 1877: 1871: 1865: 1862: 1854: 1851: 1845: 1836: 1830: 1827: 1821: 1815: 1807: 1804: 1796: 1793: 1790: 1787: 1784: 1780: 1776: 1771: 1768: 1765: 1761: 1749: 1743: 1740: 1734: 1728: 1720: 1717: 1711: 1707: 1699: 1696: 1693: 1689: 1682: 1671: 1665: 1662: 1656: 1650: 1642: 1639: 1633: 1625: 1624: 1623: 1599: 1596: 1593: 1590: 1580: 1577: 1574: 1571: 1559: 1554: 1551: 1548: 1545: 1542: 1538: 1534: 1531: 1526: 1523: 1520: 1517: 1513: 1506: 1503: 1500: 1490: 1487: 1484: 1481: 1471: 1468: 1465: 1462: 1450: 1445: 1442: 1439: 1436: 1433: 1429: 1421: 1418: 1415: 1412: 1402: 1399: 1396: 1393: 1381: 1376: 1373: 1370: 1367: 1364: 1360: 1352: 1349: 1346: 1334: 1331: 1324: 1321: 1318: 1306: 1303: 1297: 1292: 1287: 1284: 1281: 1277: 1269: 1268: 1267: 1250: 1245: 1241: 1232: 1226: 1223: 1219: 1210: 1207: 1204: 1200: 1193: 1188: 1184: 1180: 1175: 1172: 1165: 1162: 1158: 1153: 1145: 1144: 1143: 1141: 1136: 1132: 1128: 1124: 1096: 1092: 1088: 1085: 1081: 1077: 1072: 1068: 1064: 1060: 1030: 1026: 1022: 1013: 1009: 991: 987: 981: 978: 975: 971: 965: 962: 959: 955: 947: 940: 934: 928: 924: 920: 916: 912: 908: 900: 899: 898: 897: 893: 890: 886: 882: 878: 874: 870: 866: 862: 858: 854: 850: 846: 842: 841: 840: 838: 834: 830: 826: 821: 817: 812: 810: 792: 789: 782: 779: 775: 770: 766: 758: 754: 747: 725: 721: 717: 713: 709: 690: 685: 681: 676: 672: 664: 659: 655: 652: 647: 643: 612: 609: 606: 603: 590: 587: 584: 582: 574: 571: 566: 562: 552: 549: 544: 540: 526: 520: 517: 511: 505: 502: 496: 493: 487: 474: 469: 466: 462: 458: 456: 449: 445: 439: 435: 423: 422: 421: 402: 398: 394: 391: 387: 383: 378: 374: 370: 366: 337: 334: 331: 309: 305: 296: 292: 291:Hecke algebra 288: 284: 280: 261: 255: 247: 243: 235: 233: 231: 227: 223: 219: 215: 211: 210:Verma modules 207: 202: 200: 196: 192: 188: 184: 180: 176: 171: 169: 165: 161: 157: 153: 139: 130: 126: 122: 114: 112: 110: 106: 102: 99: 98:Coxeter group 95: 91: 87: 83: 80: and 79: 60: 52: 49: 46: 42: 34: 30: 19: 4961: 4957: 4932:math/0403496 4922: 4918: 4885: 4881: 4836: 4830: 4827:Vogan, David 4792: 4766: 4760: 4708: 4702: 4678: 4630: 4624: 4607: 4601: 4574: 4570: 4548: 4541:Billey, Sara 4531: 4514: 4481: 4477: 4464: 4455: 4176: 4158: 4151: 4142: 4101:flag variety 4094: 4081: 4075: 4025: 3998: 3985:Grassmannian 3974: 3927: 3923: 3919: 3915: 3906: 3897: 3889: 3885: 3884: 3876: 3871: 3859: 3846: 3836: 3706: 3701: 3697: 3693: 3691: 3675: 3671: 3666: 3662: 3658: 3654: 3650: 3646: 3640: 3628: 3572: 3568: 3564: 3557: 3550: 3543: 3541: 3535: 3530: 3529:in category 3520: 3516: 3512: 3508: 3504: 3502:vanishes if 3494: 3487: 3483: 3321: 3286: 3282: 3280: 3266: 3262: 3258: 3254: 3248: 3244: 3240: 3233: 3223: 3197: 3188: 3185: 2903: 2899: 2895: 2887: 2883: 2864: 2860: 2856: 2834: 2830: 2826: 2821:Verma module 2809: 2804:be a finite 2801: 2799: 2795:Lie algebras 2786: 2784: 2200: 2195: 2191: 2187: 2183: 2178: 2174: 2170: 2166: 2162: 2158: 2154: 2150: 2146: 2139: 2135: 2128: 2124: 2119: 2115: 2111: 2104: 2097: 2093: 2086: 2085:= 1 for all 2081: 2077: 2073: 2062: 2058: 2050: 2046: 2042: 2036: 2032: 2028: 2024: 2019: 2015: 2007: 2003: 1999: 1995: 1991: 1974: 1970: 1968: 1621: 1265: 1139: 1134: 1130: 1126: 1119: 1117: 1011: 894:The elements 888: 884: 880: 876: 872: 868: 864: 860: 856: 853:Bruhat order 848: 844: 836: 832: 828: 824: 819: 815: 813: 808: 723: 719: 715: 707: 688: 683: 679: 674: 670: 662: 657: 653: 650: 645: 641: 631: 294: 286: 282: 278: 248:, and write 245: 241: 239: 203: 191:Mark Goresky 172: 118: 100: 93: 89: 32: 26: 5057:Polynomials 4843:: 365–379, 4715:: 165–184, 4637:: 387–410, 3685:are called 3324:David Vogan 2842:), and let 2840:Weyl vector 2787:Inventiones 2774:Polo (1999) 718:that sends 154:related to 5051:Categories 5008:U.C. Davis 4500:References 4367:such that 4173:Inequality 4157:, such as 3645:the space 3527:Ext groups 3276:category O 2812:denote by 2806:Weyl group 867:, and for 236:Definition 158:which are 125:Weyl group 105:Weyl group 4990:205929043 4971:1211.4305 4949:120459494 4902:1088-4165 4873:120917588 4865:0020-9910 4791:(1980b), 4745:120098142 4737:0020-9910 4659:0020-9910 4049:∖ 3989:real form 3948:∖ 3817:¯ 3771:⁡ 3749:∑ 3484:and that 3437:⁡ 3426:− 3414:ℓ 3411:− 3399:ℓ 3388:⁡ 3366:∑ 3313:Bernstein 3309:Beilinson 3210:) and by 3155:⁡ 3099:≤ 3092:∑ 3069:⁡ 3029:⁡ 2987:ℓ 2984:− 2972:ℓ 2961:− 2950:≤ 2943:∑ 2920:⁡ 1899:ℓ 1896:− 1884:ℓ 1866:ℓ 1863:− 1831:ℓ 1816:ℓ 1805:− 1794:≤ 1781:∑ 1744:ℓ 1741:− 1729:ℓ 1708:− 1666:ℓ 1663:− 1651:ℓ 1504:− 1227:ℓ 1224:− 1185:∑ 1173:− 1163:− 1086:− 963:≤ 956:∑ 935:ℓ 929:− 891:) − 1)/2. 790:− 780:− 726:and each 607:∈ 572:− 521:ℓ 506:ℓ 488:ℓ 392:− 335:∈ 256:ℓ 224:relating 160:unipotent 140:ℓ 109:Lie group 5041:software 5027:programs 5025:The GAP 5004:Readings 4667:18403883 4579:Springer 4547:(2000), 4530:(1993), 4513:(1981), 4097:geometry 4011:in that 2902:-module 2123:is 1 if 1985:Examples 1977:without 1567:if  1458:if  1389:if  1342:if  1322:≰ 1314:if  1031:′ 917:′ 859:), 1 if 851:(in the 599:if  483:if  289:). The 201:groups. 5034:Coxeter 4910:1698201 4845:Bibcode 4717:Bibcode 4687:1106905 4639:Bibcode 4490:2454587 3841:of the 3641:By the 3315: ( 3230:Remarks 3218: ( 3206: ( 2868:. Both 2819:be the 2161:} with 2068:is the 807:; also 123:of the 84: ( 5039:Atlas 4988:  4947:  4908:  4900:  4871:  4863:  4811:  4743:  4735:  4685:  4665:  4657:  4585:  4555:  4488:  3922:where 3186:where 2199:= 1 + 2182:= 1 + 127:of an 96:of a 4986:S2CID 4966:arXiv 4945:S2CID 4927:arXiv 4869:S2CID 4839:(2), 4741:S2CID 4711:(2), 4663:S2CID 4633:(3), 4474:(PDF) 4447:Notes 3983:in a 2196:acbca 2186:and 2072:then 2041:then 1998:then 871:< 691:) = 0 678:+ 1)( 181:. In 107:of a 4898:ISSN 4861:ISSN 4809:ISBN 4733:ISSN 4655:ISSN 4583:ISBN 4553:ISBN 4428:> 4397:> 4332:> 4302:and 4287:< 4136:and 4119:and 4107:and 4001:, a 3898:real 3515:) + 3486:Ext( 3317:1993 3265:) − 3247:) − 3220:1981 3208:1981 2875:and 2863:) − 2833:) − 2800:Let 2793:and 2210:the 2179:bacb 2165:and 2054:= 1. 2031:) − 2022:and 1973:and 1788:< 1597:< 1578:> 1488:< 1469:< 1419:< 1400:< 883:) − 324:for 220:and 212:and 193:and 177:for 86:1979 31:, a 4976:doi 4962:120 4937:doi 4890:doi 4853:doi 4801:doi 4771:doi 4725:doi 4647:doi 4028:of 3997:of 3845:of 3768:dim 3674:of 3395:Ext 3385:dim 3322:3. 3319:). 3293:y,w 3283:all 2716:492 2700:677 2678:426 2656:239 2634:820 2628:129 2612:611 2606:363 2590:567 2584:906 2561:441 2555:015 2533:369 2527:964 2505:956 2499:778 2477:915 2471:859 2449:808 2443:808 2421:003 2415:159 2386:012 2380:964 2358:059 2352:067 2330:892 2324:370 2302:021 2296:293 2280:791 2258:472 2232:152 2149:= { 2134:If 2103:or 2092:If 2057:If 2014:If 1990:If 855:of 835:of 733:to 722:to 700:by 665:− 1 293:of 228:of 189:of 131:on 5053:: 5017:. 4984:, 4974:, 4960:, 4943:, 4935:, 4921:, 4906:MR 4904:, 4896:, 4884:, 4867:, 4859:, 4851:, 4837:71 4835:, 4825:; 4807:, 4787:; 4767:38 4765:, 4755:; 4739:, 4731:, 4723:, 4709:53 4707:, 4697:; 4683:MR 4661:, 4653:, 4645:, 4631:64 4629:, 4619:; 4608:49 4606:, 4600:, 4581:, 4571:R- 4543:; 4526:; 4509:; 4486:MR 4480:, 4476:, 4443:. 4169:. 4140:. 4132:, 4115:, 4087:. 3930:a 3633:. 3571:= 3556:= 3507:+ 3493:, 3278:. 3261:+ 3226:. 3152:ch 3066:ch 3026:ch 2917:ch 2732:61 2672:11 2650:41 2569:10 2541:11 2513:12 2485:13 2457:14 2437:11 2429:15 2409:11 2394:16 2366:17 2338:18 2310:19 2288:20 2274:38 2266:21 2240:22 2192:ac 2157:, 2153:, 2061:= 2018:≤ 1994:≤ 1135:yw 1122:yw 863:= 847:≤ 831:, 820:yw 702:−T 687:− 661:+ 649:= 111:. 92:, 5021:. 4993:. 4978:: 4968:: 4952:. 4939:: 4929:: 4923:6 4913:. 4892:: 4886:3 4876:. 4855:: 4847:: 4818:. 4803:: 4780:. 4773:: 4748:. 4727:: 4719:: 4690:. 4670:. 4649:: 4641:: 4612:. 4592:. 4562:. 4536:. 4519:. 4482:9 4471:" 4468:8 4465:E 4431:0 4425:) 4422:1 4419:( 4414:w 4411:, 4408:u 4405:t 4401:P 4394:) 4391:1 4388:( 4383:w 4380:u 4376:P 4355:t 4335:1 4329:) 4326:1 4323:( 4318:w 4315:u 4311:P 4290:w 4284:u 4263:) 4260:q 4257:( 4252:w 4249:u 4245:P 4223:) 4220:S 4217:, 4214:W 4211:( 4191:1 4188:= 4185:q 4085:8 4082:E 4072:. 4060:B 4056:/ 4052:G 4046:K 4032:R 4030:K 4026:K 4018:R 4016:G 4008:R 4006:K 3999:G 3994:R 3992:G 3971:, 3959:B 3955:/ 3951:G 3945:B 3928:B 3924:G 3920:B 3918:/ 3916:G 3872:y 3867:y 3865:X 3860:i 3858:2 3853:w 3851:X 3847:w 3822:) 3812:w 3808:X 3802:( 3797:i 3794:2 3787:y 3783:X 3778:H 3774:I 3763:i 3759:q 3753:i 3745:= 3742:) 3739:q 3736:( 3731:w 3728:, 3725:y 3721:P 3707:q 3705:( 3702:w 3700:, 3698:y 3694:P 3682:w 3680:X 3676:W 3672:w 3667:w 3663:X 3659:W 3655:G 3651:B 3649:/ 3647:G 3610:0 3606:w 3602:, 3599:y 3595:P 3576:0 3573:w 3569:w 3565:w 3561:1 3558:L 3554:1 3551:M 3547:1 3544:M 3536:W 3531:O 3523:) 3521:y 3519:( 3517:ℓ 3513:w 3511:( 3509:ℓ 3505:j 3500:) 3497:w 3495:L 3490:y 3488:M 3469:) 3466:) 3461:w 3457:L 3453:, 3448:y 3444:M 3440:( 3432:i 3429:2 3423:) 3420:y 3417:( 3408:) 3405:w 3402:( 3391:( 3380:i 3376:q 3370:i 3362:= 3359:) 3356:q 3353:( 3348:w 3345:, 3342:y 3338:P 3300:y 3298:L 3291:P 3272:λ 3267:ρ 3263:ρ 3259:λ 3257:( 3255:w 3249:ρ 3245:ρ 3243:( 3241:w 3192:0 3189:w 3171:) 3166:y 3162:L 3158:( 3149:) 3146:1 3143:( 3138:y 3133:0 3129:w 3125:, 3122:w 3117:0 3113:w 3108:P 3102:w 3096:y 3088:= 3085:) 3080:w 3076:M 3072:( 3045:) 3040:y 3036:M 3032:( 3023:) 3020:1 3017:( 3012:w 3009:, 3006:y 3002:P 2996:) 2993:y 2990:( 2981:) 2978:w 2975:( 2968:) 2964:1 2958:( 2953:w 2947:y 2939:= 2936:) 2931:w 2927:L 2923:( 2904:X 2900:g 2896:X 2888:W 2884:g 2879:w 2877:L 2872:w 2870:M 2865:ρ 2861:ρ 2859:( 2857:w 2855:− 2846:w 2844:L 2835:ρ 2831:ρ 2829:( 2827:w 2825:− 2816:w 2814:M 2810:W 2802:W 2751:q 2748:3 2745:+ 2740:2 2736:q 2729:+ 2724:3 2720:q 2713:+ 2708:4 2704:q 2697:, 2694:2 2691:+ 2686:5 2682:q 2675:, 2669:+ 2664:6 2660:q 2653:, 2647:+ 2642:7 2638:q 2631:, 2625:+ 2620:8 2616:q 2609:, 2603:+ 2598:9 2594:q 2587:, 2581:+ 2565:q 2558:, 2552:, 2549:2 2546:+ 2537:q 2530:, 2524:, 2521:3 2518:+ 2509:q 2502:, 2496:, 2493:6 2490:+ 2481:q 2474:, 2468:, 2465:9 2462:+ 2453:q 2446:, 2440:, 2434:+ 2425:q 2418:, 2412:, 2406:+ 2390:q 2383:, 2377:, 2374:7 2371:+ 2362:q 2355:, 2349:, 2346:4 2343:+ 2334:q 2327:, 2321:, 2318:1 2315:+ 2306:q 2299:, 2293:+ 2284:q 2277:, 2271:+ 2262:q 2255:, 2252:3 2249:+ 2236:q 2208:8 2201:q 2194:, 2188:P 2184:q 2177:, 2175:b 2171:P 2167:c 2163:a 2159:c 2155:b 2151:a 2147:S 2143:3 2140:A 2136:W 2129:w 2127:≤ 2125:y 2120:w 2118:, 2116:y 2112:P 2108:2 2105:A 2101:1 2098:A 2094:W 2089:. 2087:y 2082:w 2080:, 2078:y 2074:P 2066:0 2063:w 2059:w 2051:w 2049:, 2047:y 2043:P 2037:y 2035:( 2033:ℓ 2029:w 2027:( 2025:ℓ 2020:w 2016:y 2008:w 2006:, 2004:y 2000:P 1996:w 1992:y 1975:q 1971:q 1952:w 1949:, 1946:y 1942:P 1938:) 1933:y 1930:, 1927:x 1923:R 1919:( 1916:D 1911:) 1908:) 1905:w 1902:( 1893:) 1890:y 1887:( 1881:2 1878:+ 1875:) 1872:x 1869:( 1860:( 1855:2 1852:1 1846:q 1840:) 1837:y 1834:( 1828:+ 1825:) 1822:x 1819:( 1812:) 1808:1 1802:( 1797:w 1791:y 1785:x 1777:= 1772:w 1769:, 1766:x 1762:P 1756:) 1753:) 1750:w 1747:( 1738:) 1735:x 1732:( 1726:( 1721:2 1718:1 1712:q 1705:) 1700:w 1697:, 1694:x 1690:P 1686:( 1683:D 1678:) 1675:) 1672:x 1669:( 1660:) 1657:w 1654:( 1648:( 1643:2 1640:1 1634:q 1600:y 1594:y 1591:s 1581:x 1575:x 1572:s 1560:, 1555:y 1552:s 1549:, 1546:x 1543:s 1539:R 1535:q 1532:+ 1527:y 1524:, 1521:x 1518:s 1514:R 1510:) 1507:1 1501:q 1498:( 1491:y 1485:s 1482:y 1472:x 1466:s 1463:x 1451:, 1446:s 1443:y 1440:, 1437:s 1434:x 1430:R 1422:y 1416:y 1413:s 1403:x 1397:x 1394:s 1382:, 1377:y 1374:s 1371:, 1368:x 1365:s 1361:R 1353:y 1350:= 1347:x 1335:, 1332:1 1325:y 1319:x 1307:, 1304:0 1298:{ 1293:= 1288:y 1285:, 1282:x 1278:R 1251:. 1246:x 1242:T 1236:) 1233:x 1230:( 1220:q 1216:) 1211:y 1208:, 1205:x 1201:R 1197:( 1194:D 1189:x 1181:= 1176:1 1166:1 1159:y 1154:T 1140:q 1138:( 1131:R 1127:q 1125:( 1120:P 1102:] 1097:2 1093:/ 1089:1 1082:q 1078:, 1073:2 1069:/ 1065:1 1061:q 1057:[ 1053:Z 1027:w 1023:C 1012:D 992:y 988:T 982:w 979:, 976:y 972:P 966:w 960:y 948:2 944:) 941:w 938:( 925:q 921:= 913:w 909:C 889:y 887:( 885:ℓ 881:w 879:( 877:ℓ 873:w 869:y 865:w 861:y 857:W 849:w 845:y 837:W 833:w 829:y 825:q 823:( 816:P 809:D 793:1 783:1 776:w 771:T 767:= 764:) 759:w 755:T 751:( 748:D 737:s 735:T 730:s 728:T 724:q 720:q 716:D 708:q 704:s 697:s 695:T 689:q 684:s 680:T 675:s 671:T 669:( 663:q 658:s 654:T 651:q 646:s 642:T 636:s 634:T 613:. 610:S 604:s 591:, 588:0 585:= 578:) 575:q 567:s 563:T 559:( 556:) 553:1 550:+ 545:s 541:T 537:( 530:) 527:w 524:( 518:+ 515:) 512:y 509:( 503:= 500:) 497:w 494:y 491:( 475:, 470:w 467:y 463:T 459:= 450:w 446:T 440:y 436:T 408:] 403:2 399:/ 395:1 388:q 384:, 379:2 375:/ 371:1 367:q 363:[ 359:Z 338:W 332:w 310:w 306:T 295:W 287:S 283:w 279:w 265:) 262:w 259:( 246:S 242:W 101:W 94:w 90:y 64:) 61:q 58:( 53:w 50:, 47:y 43:P 20:)

Index

Lusztig–Vogan polynomial
representation theory
David Kazhdan
George Lusztig
1979
Coxeter group
Weyl group
Lie group
Springer representations
Weyl group
algebraic group
{\displaystyle \ell } -adic cohomology groups
conjugacy classes
unipotent
Kazhdan & Lusztig 1980a
Hecke algebra of the Coxeter group
Poincaré duality
Schubert varieties
Kazhdan & Lusztig (1980b)
intersection cohomology
Mark Goresky
Robert MacPherson
intersection cohomology
Grothendieck group
Verma modules
simple modules
Jens Carsten Jantzen
Anthony Joseph
primitive ideals
enveloping algebras

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