On local oscillatory integrals with variable Calderón-Zygmund kernels

Letp(1, ). In this paper, the authors investigate the uniformL ^p ( ⁿ ) in of the oscillatory singular integral operatorT defined by

Multilinear oscillatory integrals with Calderón-Zygmund kernel

A criterion on some boundedness is obtained for a class of multilinear oscillatory singular integrals with Calderon-Zygmund standard kernel. Project supported by the National Natural Science Foundation of China (Grnat No. 19131080).     

Boundedness of singular integrals of variable rough Calderón-Zygmund kernels along surfaces

Letn2. The authors establish theL ²( ⁿ )-boundedness of singular integrals with variable rough Calderón-Zygmund kernels associated to surfaces satisfying some conditions.The research is supported in part by the NNSF and the SEDF of China.     

Wavelet shrinkage estimators of Calderón-Zygmund operators with odd kernels

Wavelet shrinkage is a strategy to obtain a nonlinear approximation to a given function f and is widely used in data compression,signal processing and statistics,etc.For Calder′on-Zygmund operators T,it is interesting to construct estimator of T f,based on wavelet shrinkage estimator of f.With the help of a representation of operators on wavelets,due to Beylkin et al.,an estimator of T f is presented in this paper.The almost everywhere convergence and norm convergence of the proposed estimators are established.     

Calderón-Zygmund operators with kernels of Dini’s type on generalized weighted variable exponent Morrey spaces

Positivity - Let T be a Calderón-Zygmund operator of type $$omega $$ with $$omega (t)$$ being nondecreasing and satisfying a kind of Dini’s type condition and let $$T_{vec {b}}$$ be...     

Capacities Associated with Calderón-Zygmund Kernels

Analytic capacity is associated with the Cauchy kernel 1/z and the L ^∞-norm. For n?∈??, one has likewise capacities related to the kernels $K_i(x)=x_i^{2n-1}/|x|^{2n}$ , 1?≤?i?≤?2, $x=(x_1,x_2)\in{\mathbb R}^2$ . The main result of this paper states that the capacities associated with the vectorial kernel (K ₁, K ₂) are comparable to analytic capacity.     

The algebra of Calderón-Zygmund kernels on a homogeneous group is inverse-closed

We show that the subalgebra of convolution operators with Calderón-Zygmund kernels on a homogeneous group G is inverse-closed in the algebra of all bounded linear operators on the Hilbert space L ²(G). The main tool used is a symbolic calculus, where the convolution of distributions on the group is translated via the abelian Fourier transform into a “twisted product” of symbols on the dual to the Lie algebra g of G.     

Θ-type Calderón-Zygmund operators with non-doubling measures

Let µ be a Radon measure on ? ^d which may be non-doubling. The only condition that µ must satisfy is µ(B(x, r)) ≤ Cr ⁿ for all x∈? ^d , r > 0 and for some fixed 0 < n ≤ d. In this paper, under this assumption, we prove that θ-type Calderón-Zygmund operator which is bounded on L ²(µ) is also bounded from L ^∞(µ) into RBMO(µ) and from H _atb ^1,∞ (µ) into L ¹(µ). According to the interpolation theorem introduced by Tolsa, the L ^p (µ)-boundedness (1 < p < ∞) is established for θ-type Calderón-Zygmund operators. Via a sharp maximal operator, it is shown that commutators and multilinear commutators of θ-type Calderón-Zygmund operator with RBMO(µ) function are bounded on L ^p (µ) (1 < p < ∞).     

Maximal multilinear Calderón-Zygmund operators with non-doubling measures

Under the assumption that μ is a non-doubling measure on ℝ ^d which only satisfies some growth condition, the authors prove that the maximal multilinear Calderón-Zygmund operator is bounded from (μ) × … × (μ) into L ^p (μ) for any p ₁, … p _m ∈ (1, ∞) and p with 1/p = 1/p ₁ + … + 1/p _m , and bounded from (μ) × … × (μ) into weak- ^{L p} (μ) if there exists any p _i = 1. Furthermore, the authors establish a weighted weak-type estimate for the maximal multilinear Calderón-Zygmund operator. The second (corresponding) author is supported by Tianyuan Fund of China (No. 10626055) and National Natural Science Foundation of China (No. 10701078).     

Hypersingular parameterized Marcinkiewicz integrals with variable kernels on Sobolev and Hardy-Sobolev spaces

Let α≥ 0 and 0 〈 ρ ≤ n/2, the boundedness of hypersingular parameterized Marcinkiewicz integrals μΩ,α^ρ with variable kernels on Sobolev spaces Lα^ρ and HardySobolev spaces Hα^ρ is established.     

Multiple weighted estimates for maximal vector-valued commutator of multilinear Calderón-Zygmund singular integrals

This paper concerns with multiple weighted norm inequalities for maximal vector-valued multilinear singular operator and maximal commutators. The Cotlar-type inequality of maximal vector-valued multilinear singular integrals operator is obtained. On the other hand, pointwise estimates for sharp maximal function of two kinds of maximal vector-valued multilinear singular integrals and maximal vector-valued commutators are also established. By the weighted estimates of a class of new variant maximal operator, Cotlar's inequality and the sharp maximal function estimates, multiple weighted strong estimates and weak estimates for maximal vector-valued singular integrals of multilinear operators and those for maximal vector-valued commutator of multilinear singular integrals are obtained.     

Boundedness of Calderón-Zygmund operators with finite non-doubling measures

Let μ be a nonnegative Radon measure on ?d which satisfies the polynomial growth condition that there exist positive constants C₀ and n ∈ (0, d] such that, for all x ∈ ?d and r>0, μ(B(x, r))≤C0rn, where B(x, r) denotes the open ball centered at x and having radius r. In this paper, we show that, if μ(?d)<∞, then the boundedness of a Calderón-Zygmund operator T on L²(μ) is equivalent to that of T from the localized atomic Hardy space h¹(μ) to L^1,∞(μ) or from h¹(μ) to L¹(μ).     

A new approach to L p estimates for Calderón-Zygmund type singular integrals

In this paper we give a new proof for L^p estimates of the Calderón-Zygmund type singular integrals. Our approach is completely free from harmonic analysis. This work was partially supported by the innovation foundation of Shanghai university under Grant A10-0101-08-905.     

Littlewood-Paley operators with variable kernels

In this paper we study a certain directional Hilbert transform and the bound-edness on some mixed norm spaces. As one of applications, we prove the Lp-boundedness of the Littlewood-Paley operators with variable kernels. Our results are extensions of some known theorems.     

On an estimate of Calderón-Zygmund operators by dyadic positive operators

Given a general dyadic grid D and a sparse family of cubes S = {Q _j ^k ∈ D, define a dyadic positive operator A _D,S by $${A_{D,S}}f(x) = \sum\limits_{j,k} {{f_{Q_j^k}}{\chi _{Q_j^k}}} (x)$$ . Given a Banach function space X(? ⁿ ) and the maximal Calderón-Zygmund operator ${T_\natural }$ , we show that $${\left\| {{T_\natural}f} \right\|_X} \leqslant c(T,n)\mathop {\sup }\limits_{D,S} {\left\| {{A_{D,S}}|f|} \right\|_X}$$ This result is applied to weighted inequalities. In particular, it implies (i) the “twoweight conjecture” by D. Cruz-Uribe and C. Pérez in full generality; (ii) a simplification of the proof of the “A ₂ conjecture”; (iii) an extension of certain mixed A _p ?A _r estimates to general Calderón-Zygmund operators; (iv) an extension of sharp A ₁ estimates (known for T ) to the maximal Calderón-Zygmund operator $\natural $ .     

On Calderón-Toeplitz operators

We discuss boundedness and Schatten ideal criteria for a class of Toeplitz style operators based on the Calderón reproducing formula. These operators are a variation on Calderón-Zygmund operators but our results also apply to classical Toeplitz operators acting on the weighted Bergman space of the upper half plane.     

广义Calderón-Zygmund算子交换子的有界性

讨论了广义Calderón-Zyginund算子与Lipschitz函数生成的交换子在Lebe-sgue空间及Hardy空间上的有界性,同时得到了其端点估计.     

Endpoint estimates for Calderón-Zygmund type operators

In this paper, the author states three classes of endpoint estimates for Calderon-Zygmund type operators. As their special cases, the corresponding results of classical Calderon-Zygmund operators can be deduced respectively.     

Calderón-Zygmund算子在CH_p~q上的有界性

本文讨论了δ－Calderon－Zygmund算子以及θ（t）－Calderon－Zygmund算子在Hardy型空间CHqp上的有界性．