Sobolev spaces on Lie groups : Embedding theorems and algebra properties

Let G be a noncompact connected Lie group, denote with ρ a right Haar measure and choose a family of linearly independent left-invariant vector fields X on G satisfying Hörmander's condition. Let χ be a positive character of G and consider the measure μχ whose density with respect to ρ is χ. In this paper, we introduce Sobolev spaces Lα p(μχ) adapted to X and μχ (1