We introduce a new “weak” BMO-regularity condition for couples (X,Y) of lattices of measurable functions on the circle (Definition 3, Section 9), describe it in terms of the lattice $X^{1/2}{\left(Y^{\text{'}}\right)}^{1/2}$, and prove that this condition still ensures “good” interpolation for the couple $(X_A,Y_A)$ of the Hardy-type spaces corresponding to X and Y (Theorem 1, Section 9). Also, we present a neat version of Pisier’s approach to interpolation of Hardy-type subspaces (Theorem 2, Section 13). These two main results of the paper are...

Let A be a uniform algebra on X and σ a probability measure on X. We define the Hardy spaces $H^p\left(\sigma \right)$ and the $H^p\left(\sigma \right)$ interpolating sequences S in the p-spectrum ${ℳ}_p$ of σ. We prove, under some structural hypotheses on A and σ, that if S is a “dual bounded” Carleson sequence, then S is $H^s\left(\sigma \right)$-interpolating with a linear extension operator for s < p, provided that either p = ∞ or p ≤ 2. In the case of the unit ball of ℂⁿ we find, for instance, that if S is dual bounded in $H^{\infty }\left(\right)$ then S is $H^p\left(\right)$-interpolating with a linear...

In this paper we prove the continuity of fractional integrals acting on nonhomogeneous function spaces defined on spaces of homogeneous type with finite measure. A definition of the molecules which are used in the $H^p$ theory is given. Results are proved for $L^p$, $H^p$, BMO, and Lipschitz spaces.

We consider and solve extremal problems in various bounded weakly pseudoconvex domains in ${ℂ}^n$ based on recent results on boundedness of Bergman projection with positive Bergman kernel in Bergman spaces $A_{\alpha }^p$ in such type domains. We provide some new sharp theorems for distance function in Bergman spaces in bounded weakly pseudoconvex domains with natural additional condition on Bergman representation formula.

We present new sharp embedding theorems for mixed-norm analytic spaces in pseudoconvex domains with smooth boundary. New related sharp results in minimal bounded homogeneous domains in higher dimension are also provided. Last domains we consider are domains which are direct generalizations of the well-studied so-called bounded symmetric domains in ${ℂ}^n.$ Our results were known before only in the very particular case of domains of such type in the unit ball. As in the unit ball case, all our proofs are...

We obtain new sharp embedding theorems for mixed-norm Herz-type analytic spaces in tubular domains over symmetric cones. These results enlarge the list of recent sharp theorems in analytic spaces obtained by Nana and Sehba (2015).

Let $A_1,\cdots ,A_m$ be $n\times n$ real matrices such that for each $1\le i\le m,$$A_i$ is invertible and $A_i-A_j$ is invertible for $i\ne j$. In this paper we study integral operators of the form $$Tf\left(x\right)=\int k_1(x-A_{1}y)k_2(x-A_{2}y)\cdots k_m(x-A_{m}y)f\left(y\right)\mathrm{d}y,$$$...$

The point-wise product of a function of bounded mean oscillation with a function of the Hardy space $H^1$ is not locally integrable in general. However, in view of the duality between $H^1$ and $BMO$, we are able to give a meaning to the product as a Schwartz distribution. Moreover, this distribution can be written as the sum of an integrable function and a distribution in some adapted Hardy-Orlicz space. When dealing with holomorphic functions in the unit disc, the converse is also valid: every holomorphic...

We consider a convolution operator Tf = p.v. Ω ⁎ f with $\Omega \left(x\right)=K\left(x\right)e^{ih\left(x\right)}$, where K(x) is an (n,β) kernel near the origin and an (α,β), α ≥ n, kernel away from the origin; h(x) is a real-valued $C^{\infty }$ function on ${ℝ}^n\setminus 0$. We give a criterion for such an operator to be bounded from the space $H_0^p\left({ℝ}^n\right)$ into itself.

Let $Tf\left(x\right)=p.v.{ʃ}_{ℝ¹}{e}^{iP(x-y)}f\left(y\right)/(x-y)dy$, where P is a real polynomial on ℝ. It is proved that T is bounded on the weighted H¹(wdx) space with w ∈ A₁.

Let 1 ≤ p ≤ ∞ and let $w_0,w_1$ be two weights on the unit circle such that $log\left(w_0{w}_1^{-1}\right)\in BMO$. We prove that the couple $(H_p\left(w_0\right),H_p\left(w_1\right))$ of weighted Hardy spaces is a partial retract of $(L_p\left(w_0\right),L_p\left(w_1\right))$. This completes previous work of the authors. More generally, we have a similar result for finite families of weighted Hardy spaces. We include some applications to interpolation.