Let G be a real connected Lie group with polynomial volume growth endowed with its Haar measuredx. Given a C² positive bounded integrable function M on G, we give a sufficient condition for an L² Poincaré inequality with respect to the measure M(x)dx to hold on G. We then establish a nonlocal Poincaré inequality on G with respect to M(x)dx. We also give analogous Poincaré inequalities on Riemannian manifolds and deal with the case of Hardy inequalities.

The main purpose of the present paper is to extend the theory of non-smooth atomic decompositions to anisotropic function spaces of Besov and Triebel-Lizorkin type. Moreover, the detailed analysis of the anisotropic homogeneity property is carried out. We also present some results on pointwise multipliers in special anisotropic function spaces.

We give norm inequalities for some classical operators in amalgam spaces and in some subspaces of Morrey space.

We study the duality theory of the weighted multi-parameter Triebel-Lizorkin spaces ${\dot{F}}_p^{\alpha ,q}(\omega ;{ℝ}^{n_1}\times {ℝ}^{n_2})$. This space has been introduced and the result $${\left({\dot{F}}_p^{\alpha ,q}(\omega ;{ℝ}^{n_1}\times {ℝ}^{n_2})\right)}^{*}={\mathrm{CMO}}_p^{-\alpha ,q^{\text{'}}}(\omega ;{ℝ}^{n_1}\times {ℝ}^{n_2})$$ for $0<p\le 1$ has been proved in Ding, Zhu (2017). In this paper, for $1<p<\infty$, $0<q<\infty$ we establish its dual space ${\dot{H}}_p^{\alpha ,q}(\omega ;{ℝ}^{n_1}\times {ℝ}^{n_2})$.