Smallness problem for quantum affine algebras and quiver varieties
Annales scientifiques de l'École Normale Supérieure, Serie 4, Volume 41 (2008) no. 2, p. 271-306

The geometric small property (Borho-MacPherson [2]) of projective morphisms implies a description of their singularities in terms of intersection homology. In this paper we solve the smallness problem raised by Nakajima [37, 35] for certain resolutions of quiver varieties [37] (analogs of the Springer resolution): for Kirillov-Reshetikhin modules of simply-laced quantum affine algebras, we characterize explicitly the Drinfeld polynomials corresponding to the small resolutions. We use an elimination theorem for monomials of Frenkel-Reshetikhin q-characters that we establish for non necessarily simply-laced quantum affine algebras. We also refine results of [21] and extend the main result to general simply-laced quantum affinizations, in particular to quantum toroidal algebras (double affine quantum algebras).

La propriété géométrique de petitesse (Borho-MacPherson [2]) des morphismes projectifs implique une description de leurs singularités en termes d’homologie d’intersection. Dans cet article nous résolvons le problème de petitesse posé par Nakajima [37, 35] pour certaines résolutions de variétés carquois [37] (analogues de la résolution de Springer) : pour les modules de Kirillov-Reshetikhin des algèbres affines quantiques simplement lacées, nous caractérisons explicitement les polynômes de Drinfeld correspondant aux résolutions petites. Nous utilisons un théorème d’élimination pour les monômes des q-caractères de Frenkel-Reshetikhin, que nous établissons pour les algèbres affines quantiques non nécessairement simplement lacées. Nous raffinons également des résultats de [21] et étendons le résultat principal aux affinisées quantiques générales simplement lacées, en particulier aux algèbres toroïdales quantiques (algèbres quantiques doublement affines).

DOI : https://doi.org/10.24033/asens.2068
Classification:  17B37,  14L30,  81R50,  82B23,  17B67
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     author = {Hernandez, David},
     title = {Smallness problem for quantum affine algebras and quiver varieties},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {Ser. 4, 41},
     number = {2},
     year = {2008},
     pages = {271-306},
     doi = {10.24033/asens.2068},
     zbl = {1189.17014},
     mrnumber = {2468483},
     language = {en},
     url = {http://www.numdam.org/item/ASENS_2008_4_41_2_271_0}
}
Hernandez, David. Smallness problem for quantum affine algebras and quiver varieties. Annales scientifiques de l'École Normale Supérieure, Serie 4, Volume 41 (2008) no. 2, pp. 271-306. doi : 10.24033/asens.2068. http://www.numdam.org/item/ASENS_2008_4_41_2_271_0/

[1] A. A. Beilinson, J. Bernstein & P. Deligne, Faisceaux pervers, in Analysis and topology on singular spaces, I (Luminy, 1981), Astérisque 100, Soc. Math. France, 1982, 5-171. | Zbl 0536.14011

[2] W. Borho & R. Macpherson, Partial resolutions of nilpotent varieties, in Analysis and topology on singular spaces, II, III (Luminy, 1981), Astérisque 101, Soc. Math. France, 1983, 23-74. | Zbl 0576.14046

[3] N. Bourbaki, Éléments de mathématique. Groupes et algèbres de Lie. Chapitres 4 à 6, Paris, Hermann, 1968 ; Springer, 2007. | Zbl 1120.17002

[4] V. Chari & A. A. Moura, Characters and blocks for finite-dimensional representations of quantum affine algebras, Int. Math. Res. Not. 5 (2005), 257-298. | Zbl 1074.17004

[5] V. Chari & A. A. Moura, Characters of fundamental representations of quantum affine algebras, Acta Appl. Math. 90 (2006), 43-63. | Zbl 1101.17016

[6] V. Chari & A. Pressley, Quantum affine algebras, Comm. Math. Phys. 142 (1991), 261-283. | Zbl 0739.17004

[7] V. Chari & A. Pressley, A guide to quantum groups, Cambridge University Press, 1994. | Zbl 0839.17009

[8] V. Chari & A. Pressley, Quantum affine algebras and their representations, in Representations of groups (Banff, AB, 1994), CMS Conf. Proc. 16, Amer. Math. Soc., 1995, 59-78. | Zbl 0855.17009

[9] V. Chari & A. Pressley, Integrable and Weyl modules for quantum affine sl 2 , in Quantum groups and Lie theory (Durham, 1999), London Math. Soc. Lecture Note Ser. 290, Cambridge Univ. Press, 2001, 48-62. | Zbl 1034.17008

[10] G. W. Delius & N. J. Mackay, Affine quantum groups, in Encyclopedia of Mathematical Physics, Elsevier, 2006.

[11] V. G. DrinfelʼD, Quantum groups, in Proceedings of the International Congress of Mathematicians, Vol. 1, 2 (Berkeley, Calif., 1986), Amer. Math. Soc., 1987, 798-820. | MR 934283 | Zbl 0667.16003

[12] V. G. DrinfelʼD, A new realization of Yangians and of quantum affine algebras, Soviet Math. Dokl. 36 (1998), 212-216. | MR 914215 | Zbl 0667.16004

[13] E. Frenkel & E. Mukhin, Combinatorics of q-characters of finite-dimensional representations of quantum affine algebras, Comm. Math. Phys. 216 (2001), 23-57. | Zbl 1051.17013

[14] E. Frenkel & N. Reshetikhin, The q-characters of representations of quantum affine algebras and deformations of 𝒲-algebras, in Recent developments in quantum affine algebras and related topics (Raleigh, NC, 1998), Contemp. Math. 248, Amer. Math. Soc., 1999, 163-205. | Zbl 0973.17015

[15] M. Goresky & R. Macpherson, Intersection homology theory, Topology 19 (1980), 135-162. | Zbl 0448.55004

[16] M. Goresky & R. Macpherson, Intersection homology. II, Invent. Math. 72 (1983), 77-129. | Zbl 0529.55007

[17] R. M. Hardt, Semi-algebraic local-triviality in semi-algebraic mappings, Amer. J. Math. 102 (1980), 291-302. | MR 564475 | Zbl 0465.14012

[18] D. Hernandez, Algebraic approach to q,t-characters, Adv. Math. 187 (2004), 1-52. | MR 2074171 | Zbl 1098.17009

[19] D. Hernandez, Monomials of q and q,t-characters for non simply-laced quantum affinizations, Math. Z. 250 (2005), 443-473. | MR 2178794 | Zbl 1098.17010

[20] D. Hernandez, Representations of quantum affinizations and fusion product, Transform. Groups 10 (2005), 163-200. | MR 2195598 | Zbl 1102.17009

[21] D. Hernandez, The Kirillov-Reshetikhin conjecture and solutions of T-systems, J. reine angew. Math. 596 (2006), 63-87. | MR 2254805 | Zbl 1160.17010

[22] D. Hernandez, Drinfeld coproduct, quantum fusion tensor category and applications, Proc. Lond. Math. Soc. 95 (2007), 567-608. | MR 2368277 | Zbl 1133.17010

[23] D. Hernandez, On minimal affinizations of representations of quantum groups, Comm. Math. Phys. 276 (2007), 221-259. | MR 2342293 | Zbl 1141.17011

[24] M. Jimbo, A q-difference analogue of U(𝔤) and the Yang-Baxter equation, Lett. Math. Phys. 10 (1985), 63-69. | MR 797001 | Zbl 0587.17004

[25] V. G. Kac, Infinite-dimensional Lie algebras, third éd., Cambridge University Press, 1990. | MR 1104219 | Zbl 0574.17010

[26] A. N. Kirillov & N. Reshetikhin, Representations of Yangians and multiplicities of the inclusion of the irreducible components of the tensor product of representations of simple Lie algebras, J. Soviet Math 52 (1990), 3156-3164, translated from Zap. Nauchn. Sem. Leningrad. Otdel. Mat. Inst. Steklov. (LOMI) 160, Anal. Teor. Chisel i Teor. Funktsii. 8, 211-221, 301 (1987). | Zbl 0900.16047

[27] H. Knight, Spectra of tensor products of finite-dimensional representations of Yangians, J. Algebra 174 (1995), 187-196. | MR 1332866 | Zbl 0868.17009

[28] A. Kuniba & J. Suzuki, Analytic Bethe ansatz for fundamental representations of Yangians, Comm. Math. Phys. 173 (1995), 225-264. | Zbl 0834.58045

[29] K. Miki, Representations of quantum toroidal algebra U q ( sl n+1, tor )(n2), J. Math. Phys. 41 (2000), 7079-7098. | MR 1781425 | Zbl 1028.17011

[30] H. Nakajima, Instantons on ALE spaces, quiver varieties, and Kac-Moody algebras, Duke Math. J. 76 (1994), 365-416. | MR 1302318 | Zbl 0826.17026

[31] H. Nakajima, Quiver varieties and Kac-Moody algebras, Duke Math. J. 91 (1998), 515-560. | MR 1604167 | Zbl 0970.17017

[32] H. Nakajima, Quiver varieties and finite-dimensional representations of quantum affine algebras, J. Amer. Math. Soc. 14 (2001), 145-238. | MR 1808477 | Zbl 0981.17016

[33] H. Nakajima, T-analogue of the q-characters of finite dimensional representations of quantum affine algebras, in Physics and combinatorics, 2000 (Nagoya), World Sci. Publ., River Edge, NJ, 2001, 196-219. | MR 1872257 | Zbl 1011.17013

[34] H. Nakajima, Geometric construction of representations of affine algebras, in Proceedings of the International Congress of Mathematicians, Vol. I (Beijing, 2002), Higher Ed. Press, 2002, 423-438. | MR 1989196 | Zbl 1049.17014

[35] H. Nakajima, Problems on quiver varieties, in The 50th Geometry Symposium, Hokkaido Univ., 2003, http://www.math.kyoto-u.ac.jp/~nakajima/TeX/kika03.pdf.

[36] H. Nakajima, t-analogs of q-characters of Kirillov-Reshetikhin modules of quantum affine algebras, Represent. Theory 7 (2003), 259-274 (electronic). | MR 1993360 | Zbl 1078.17008

[37] H. Nakajima, Quiver varieties and t-analogs of q-characters of quantum affine algebras, Ann. of Math. 160 (2004), 1057-1097. | MR 2144973 | Zbl 1140.17015

[38] O. Schiffmann, Nakajima's quiver varieties, Séminaire Bourbaki 2006/07, exposé no 976, Astérisque (2008), 295-344. | MR 2487738 | Zbl 1151.14026

[39] R. Thom, Ensembles et morphismes stratifiés, Bull. Amer. Math. Soc. 75 (1969), 240-284. | MR 239613 | Zbl 0197.20502

[40] M. Varagnolo & É. Vasserot, Standard modules of quantum affine algebras, Duke Math. J. 111 (2002), 509-533. | Zbl 1011.17012