First, we define a generalization of the standard quantum Toda chain inspired by a construction of quantum cohomology of partial flags spaces GL +1 /P , P a parabolic subgroup. Common eigenfunctions of the parabolic quantum Toda chains are generalized Whittaker functions given by matrix elements of infinite-dimensional representations of gl +1 . For maximal parabolic subgroups (i.e., for P such that GL +1 /P = P ) we construct two different representations of the corresponding parabolic Whittaker functions as correlation functions in topological quantum field theories on a two-dimensional disk. In one case the parabolic Whittaker function is given by a correlation function in a type-A equivariant topological sigma model with the target space P . In the other case, the same Whittaker function appears as a correlation function in a type-B equivariant topological Landau-Ginzburg model related with the type-A model by mirror symmetry. This note is a continuation of our project of establishing a relation between twodimensional topological field theories (and more generally topological string theories) and Archimedean (∞-adic) geometry. From this perspective the existence of two, mirror dual, topological field theory representations of the parabolic Whittaker functions provide a quantum field theory realization of the local Archimedean Langlands duality for Whittaker functions. The established relation between the Archimedean Langlands duality and mirror symmetry in two-dimensional topological quantum field theories should be considered as a main result of this note.
IntroductionIn [17,18] we propose two-dimensional topological field theories as a proper framework for a description of the Archimedean completion of arithmetic schemes (∞-adic geometry according to [28]). In particular, we give a representation of local Archimedean L-factors (we include local epsilon-factor in the definition of the L-factors) in terms of two-dimensional topological field theories. It is well-known that local L-factors allow two types of 135 136 Anton Gerasimov, Dimitri Lebedev and Sergey Oblezin constructions -"arithmetic" construction based on representation theory of the Weil-Deligne group of the local field and "automorphic" construction relying on representation theory of reductive groups over local field (see, e.g., [1,6,7]). The equivalence of these constructions for various types of L-factors is a subject of the local Langlands duality. In an interpretation suggested in [17,18] the "arithmetic" construction of local Archimedean L-factors is naturally identified with a type-A topological field theory description [17] in terms of equivariant volumes of spaces of holomorphic maps of a disk into complex vector spaces. The "automorphic" construction of the same local L-factors is realized using a type-B topological field theory via periods of holomorphic forms [18]. The Archimedean Langlands duality between these two constructions of the local Archimedean L-factors appears as a mirror duality between underlying type-A and type-B topolo...