L^(2) Boundedness of the Fourier Integral Operator with Inhomogeneous Phase Functions

In this paper,we investigate the L^(2) boundedness of the Fourier integral operator Tφ,a with smooth and rough symbols and phase functions which satisfy certain non-degeneracy conditions.In particular,if the symbol a∈L∞Smρ,the phase functionφsatisfies some measure conditions and ∇kξφ(·,ξ)L∞≤C|ξ|−k for all k≥2,ξ≠0,and some∈>0,we obtain that Tφ,a is bounded on L^(2) if m<n2 min{ρ−1,−2}.This result is a generalization of a result of Kenig and Staubach on pseudo-differential operators and it improves a result of Dos Santos Ferreira and Staubach on Fourier integral operators.Moreover,the Fourier integral operator with rough symbols and inhomogeneous phase functions we study in this paper can be used to obtain the almost everywhere convergence of the fractional Schr odinger operator.

Multilinear Hausdorff Operators and Their Best Constants

In this paper, we study two different extensions of the Hausdorff operator to the multilinear case. Boundedness on Lebesgue spaces and Herz spaces is obtained. The bound on the Lebesgue space is optimal. Our results are substantial extensions of some known results on Multilinear high dimensional Hardy operator.

Sharp L^2 Boundedness of the Oscillatory Hyper-Hilbert Transform along Curves

Consider the oscillatory hyper-Hilbert transform Hn,α,βf（x）=∫0^1 f（x-Г（t））e^it-βt^-1-α dt along the curve P（t） = （tp1, tP2,..., tpn）, where β 〉 α ≥ 0 and 0 〈 p1 〈 p2 〈 ... 〈 Pn. We prove that H n,α,β is bounded on L2 if and only if β ≥ （n ＋ 1）α. Our work extends and improves some known results.

Boundedness of an Oscillating Multiplier on Triebel-Lizorkin Spaces

Abstract In this paper, we study Triebel-Lizorkin space estimates for an oscillating multiplier mΩ,α,β. This operator was initially studied by Wainger and by Fefferman-Stein in the Lebesgue spaces. We obtain the boundedness results on the Triebel-Lizorkin space Fpα,q（R^n） for different p, q.

The (L^p,F_p^(β,∞))-Boundedness of Commutators of Multipliers

In this paper, we study the commutator generalized by a multiplier and a Lipschitz function. Under some assumptions, we establish the boundedness properties of it from L^P（R^n） into Fp^β,∞（R^n）, the Triebel Lizorkin spaces.

Global Well-posedness of Generalized Magnetohydrodynamics Equations in Variable Exponent Fourier–Besov–Morrey Spaces

A generalized incompressable magnetohydrodynamics system is considered in this paper.Furthermore, results of global well-posednenss are established with the aid of Littlewood–Paley decomposition and Fourier localization method in mentioned system with small initial condition in the variable exponent Fourier–Besov–Morrey spaces. Moreover, the Gevrey class regularity of the solution is also achieved in this paper.

Approximation of the Fractional Schrodinger Propagator on Compact Manifolds

Let L be a second order positive,elliptic differential operator that is self-adjoint with respect to some C^(∞)density dx on a compact connected manifold M.We proved that if 0<α<1,α/2<s<αand f∈H^(s)(M)then the fractional Schrodinger propagator e^(itLα/2) on M satisfies eitLα/2 f(x)−f(x)=o(t^(s/α−ε))almost everywhere as t→0^(+),for anyε>0.