Arkhipov, SergeyGaitsgory, Dennis2019-01-042003-01Arkhipov, Sergey, and Dennis Gaitsgory. 2003. “Another Realization of the Category of Modules over the Small Quantum Group.” Advances in Mathematics 173 (1): 114–43. https://doi.org/10.1016/s0001-8708(02)00016-6.0001-8708http://nrs.harvard.edu/urn-3:HUL.InstRepos:37971086Let g be a semi-simple simply-connected Lie algebra and let U-l be the corresponding quantum group with divided powers, where is an even order root of unity. Let in addition u(l) subset of U-l be the corresponding "small" quantum group. In this paper we establish the following relation between the categories of representations of U-l and u(l). We show that the category of u(l)-modules is naturally equivalent to the category of U-l-modules, which have a Hecke eigen-property with respect to representations lifted by means of the quantum Frobenius map U-l --> U(q), where g is the Langlands dual Lie algebra. This description allows to express the regular linkage class in the category u(l)-mod in terms of perverse sheaves on the affine flag variety with a Hecke eigen-property. Moreover, it can serve as a basis to the program to understand the connection between the category u(l)-mod and the category of representations of the corresponding affine algebra at the critical level.en-USJournal Article2019-01-0410.1016/s0001-8708(02)00016-6