In this paper, the authors establish the inhomogeneous Plancherel-Polya inequalities on spaces of homogeneous type by use of the inhomogeneous discrete Calderon reproducing formulas. As an application, the authors prove that the Lebesgue norms of the inhomogeneous Littlewood-Paley g-function and S-function on spaces of homogeneous type are equivalent. All results are new even for Rn.

An RD-space X is a space of homogeneous type in the sense of Coifman and Weiss with the additional property that a reverse doubling property holds in X, or equivalently, that there exists a constant a0 > 1 such that for all x ∈ X and 0 < r < diam (X)=a0, the annulus B(x, a0r) n B(x, r) is nonempty, where diam (X) denotes the diameter of the metric space (X, d). An important class of RD-spaces is provided by Carnot-Caratheodory spaces with a doubling measure. In this paper, the authors introduce some spaces of Lipschitz type on RD-spaces, and discuss their relations with known Besov and Triebel-Lizorkin spaces and various Sobolev spaces.

New norms for some distributions on spaces of homogeneous type which include some fractals are introduced. Using inhomogeneous discrete Calderon reproducing formulae and the Plancherel-Polya inequalities on spaces of homogeneous type, the authors prove that these norms give a new characterization for the Besov and Triebel-Lizorkin spaces with p; q > 1 and can be used to introduce new inhomogeneous Besov and Triebel-Lizorkin spaces with p; q≤ 1 on spaces of homogeneous type. Moreover, atomic decompositions of these new spaces are also obtained. All the results of this paper are new even for Rn.

Let Γ be a compact d-set in Rn with 0 < d ≤n, which includes various kinds of fractals. The author shows that the Besov spaces Bspq(Γ) defined by two different and equivalent methods, namely, via traces and quarkonial decompositions in the sense of Triebel are the same spaces as those obtained by regarding Γ as a space of homogeneous type when 0 < s < 1, 1 < p <∞　 and 1≤q≤∞.

In this paper, we prove the product Hp boundedness of Calderon-Zygmund operators which were considered by Fefferman and Stein. The methods used in this paper are new even for the classical Hp boundedness of Calderon-Zygmund operators, namely, using some subtle estimates together with the Hp−Lp boundedness of product vector valued Calderon-Zygmund operators.