Holomorphic Functions of Exponential Type and Duality for Stein Groups   with Algebraic Connected Component of Identity
  We suggest a generalization of Pontryagin duality from the category of commutative Stein groups to the category of (not necessarily commutative) Stein groups with algebraic connected component of identity. In contrast to the other similar generalizations, in our approach the enveloping category consists of Hopf algebras (in a proper symmetrical monoidal category). 
S.S. Akbarov