海森堡群上薛定谔算子的黎斯位势的某些性质

设L=-△_(H~n)+V是Heisenberg群H~n上的Schr(o|¨)dinger算子,其中△_(H~n)为H~n上的次Laplacian,V≠0为满足逆H(o|¨)lder不等式的非负函数.本文研究H~n上Riesz位势I_α~L=L~(-α/2)在Campanato型空间A_L~β和Hardy型空间H_L~p上的某些性质.     

Hölder estimates of p-harmonic extension operators

It is now a well-known fact that for 1<p<∞ the p-harmonic functions on domains in metric measure spaces equipped with a doubling measure supporting a (1,p)-Poincaré inequality are locally Hölder continuous. In this note we provide a characterization of domains in such metric spaces for which p-harmonic extensions of Hölder continuous boundary data are globally Hölder continuous. We also provide a link between this regularity property of the domain and the uniform p-fatness of the complement of the domain.     

Parabolic Schrödinger operators

We characterize the domain of the parabolic Schrödinger operator t_∂−Δ+V in Lp(Rn+1), 1<p<∞, where the potential V is nonnegative and belongs to the Parabolic Reverse Hölder class p(PB).     

非齐型空间中一类满足Hörmander条件的Marcinkiewicz交换子估计

记μ为上的非负Radon测度,且仅满足对固定的C₀>0和n∈(0,d],及所有的和r>0, μ(B(x,r))≤C₀ rⁿ.作者建立了一类核函数满足Hörmander条件的Marcinkiewicz积分与Lip_β(μ)(0<β)函数生成的交换子由L^p(μ)到L^q(μ),由L^p(μ) 到Lip_β-n/p(μ)及L^n/β(μ)到RBMO(μ)有界.部分结论对经典 Marcinkiewicz积分也是新的.       

Remarks on Hölder continuity for solutions of the p-Laplace evolution equations

We study the interior Hölder regularity problem for the gradient of solutions of the p-Laplace evolution equations with the external forces. Misawa gave some conditions for the Hölder continuity of the gradient of solutions. We show Hölder estimates of the solutions with weaker condition as for Misawa.     

Justifying the convergence of the rectangular method for complete singular integral equations with continuous coefficients on the circle

For an integral equation on the unit circle of the form (aI + bS + K)f = g, where a and b are Hölder functions, S is a singular integration operator, and K is an integral operator with Hölder kernel, we consider a method of solution based on the discretization of integral operators using the rectangle rule. This method is justified under the assumption that the equation is solvable in L ₂() and the coefficients a and b satisfy the strong ellipticity condition.     

Some applications of reverse Hölder inequalities with a boundary integral

We obtain an increase in the exponent of integrability of the derivatives of solutions of two classes of boundary-value problems. We derive estimates of the corresponding norms of the solutions. For a class of quasilinear elliptic systems we establish an L_p-estimate of the gradient of the solutions of class W _m ¹ ,m > 1, p > m, of a boundary-value problem with nonzero condition on the conormal derivative. To solve Signorini's problem we obtain an L_p-estimate, p > 2,of the second derivatives of an L ₂-solution with a nonzero one-sided restriction on the conormal derivative. The proof of both results is based on the application of an reverse Hölder inequality with a surface integral established earlier by the author. Bibliography: 5 titles.Translated fromProblemy Matematicheskogo Analiza, No. 12, 1992, pp. 13–29.     

Some discrete Sobolev's inequalities in three-dimensional spherical and cylindrical coordinates

The discrete Sobolev's inequalities inL _p norm are proved for three-dimensional spherical and cylindrical coordinates, by using discrete Hölder inequality, property of the triangle functions and complicated deduction.     

Estimates of the Hölder constant for functions satisfying a uniformly elliptic or a uniformly parabolic quasilinear inequality with unbounded coefficients

One obtains inner and boundary estimates of the Hölder constants for functions u(·) satisfying a uniformly elliptic or uniformly parabolic quasilinear inequality of nondivergence form with unbounded coefficients. It is shown that the Hölder exponents in them depend only on the dimension W and on the constants and occurring in the ellipticity conditions. In the boundary estimates they depend also on the constant ₀, occurring in the condition (A) on the boundary and on the Hölder exponent for the boundary values of u(·).Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 147, pp. 72–94, 1985.     

Weighted estimates for commutators of some singular integrals related to Schrödinger operators

Let L=−Δ+V$L=-\mathrm{\Delta }+V$ be a Schrödinger operator with a non-negative potential V satisfying some appropriate reverse Hölder inequality. In this paper, we study the boundedness of the commutators of some singular integrals associated to L such as the Riesz transforms and fractional integrals with the new BMO functions introduced in Bongioanni et al. (2011) [1] on the weighted spaces L^p(w)$L^p(w)$ where w belongs to the new classes of weights introduced by Bongioanni et al. (2011) [2].     

Stochastic partial differential equations in M-type 2 Banach spaces

We study abstract stochastic evolution equations in M-type 2 Banach spaces. Applications to stochastic partial differential equations inL ^p spaces withp2 are given. For example, solutions of such equations are Hölder continuous in the space variables.The author is an Alexander von Humboldt Stiftung fellow     

Hölder continuity of solutions of supercritical dissipative hydrodynamic transport equations

We examine the regularity of weak solutions of quasi-geostrophic (QG) type equations with supercritical (α<1/2$\alpha <1/2$) dissipation α(−Δ)${(-\mathrm{\Delta })}^{\alpha }$. This study is motivated by a recent work of Caffarelli and Vasseur, in which they study the global regularity issue for the critical (α=1/2$\alpha =1/2$) QG equation [L. Caffarelli, A. Vasseur, Drift diffusion equations with fractional diffusion and the quasi-geostrophic equation, arXiv: math.AP/0608447, 2006]. Their approach successively increases the regularity levels of Leray–Hopf weak solutions: from L²$L^2$ to L^∞$L^{\infty }$, from L^∞$L^{\infty }$ to Hölder (Cδ$C^{\delta }$, δ>0$\delta >0$), and from Hölder to classical solutions. In the supercritical case, Leray–Hopf weak solutions can still be shown to be L^∞$L^{\infty }$, but it does not appear that their approach can be easily extended to establish the Hölder continuity of L^∞$L^{\infty }$ solutions. In order for their approach to work, we require the velocity to be in the Hölder space C1−2α$C^{1-2\alpha }$. Higher regularity starting from Cδ$C^{\delta }$ with δ>1−2α$\delta >1-2\alpha$ can be established through Besov space techniques and will be presented elsewhere [P. Constantin, J. Wu, Regularity of Hölder continuous solutions of the supercritical quasi-geostrophic equation, Ann. Inst. H. Poincaré Anal. Non Linéaire, in press].     

The Generalized Multifractional Brownian Motion

It is well known that the fractional Brownian motion (FBM) is of great interest in modeling. However, its Hölder is the same all along its path and this restricts its field of application. Therefore, it would be useful to construct a Gaussian process extending the FBM and having a Hölder that is allowed to change. A partial answer to this problem is supplied by the multifractional Brownian motion (MBM); but the Hölder of the MBM must necessarily be continuous and this may be a drawback in some situations. In this paper we construct a Gaussian process generalizing the MBM and having a Hölder that can be a very irregular function.     

The Boundary Harnack Principle for Non-Divergence form Elliptic Operators

If L is a uniformly elliptic operator in non-divergence form,the boundary Harnack principle for the ratio of positive L-harmonicfunctions holds in Hölder domains of order if > . A counterexample shows that is sharp. For Hölder domainsof order with (0,1], the boundary Harnack principle holds providedthe domain also satisfies a strong uniform regularity condition.     

Lifetimes of conditioned diffusions

Summary We investigate when an upper bound on expected lifetimes of conditioned diffusions associated with elliptic operators in divergence and non-divergence form can be found. The critical value of the parameter is found for each of the following classes of domains:L ^p -domains (p=n–1), uniformly regular twistedL ^p -domains (p=n–1), and twisted Hölder domains (=1/3). A related parabolic boundary Harnack principle is proved.     

Convergence of the variants of the Chebyshev–Halley iteration family under the Hölder condition of the first derivative

The present paper is concerned with the convergence problem of the variants of the Chebyshev–Halley iteration family with parameters for solving nonlinear operator equations in Banach spaces. Under the assumption that the first derivative of the operator satisfies the Hölder condition of order p$p$, a convergence criterion of order 1+p$1+p$ for the iteration family is established. An application to a nonlinear Hammerstein integral equation of the second kind is provided.     

Justifying the convergence of the rectangular method for complete singular integral equations with continuous coefficients on the circle

For an integral equation on the unit circle of the form (aI + bS + K)f = g, where a and b are Hölder functions, S is a singular integration operator, and K is an integral operator with Hölder kernel, we consider a method of solution based on the discretization of integral operators using the rectangle rule. This method is justified under the assumption that the equation is solvable in L ₂() and the coefficients a and b satisfy the strong ellipticity condition.Translated from Matematicheskie Zametki, vol. 77, no. 2, 2005, pp. 163–175.Original Russian Text Copyright © 2005 by M. É. Abramyan.This revised version was published online in April 2005 with a corrected issue number.     

On the inclusion of generalized Hölder classes

For the generalized Hölder classes with smoothness functions in the metric of L_p(R_N) we obtain the necessary and sufficient conditions for inclusion. There follows in particular from these conditions a new inclusion theorem with respect to the index of these classes.Translated from Matematicheskie Zametki, Vol. 12, No. 3, pp. 325–336, September, 1972.In conclusion the author wishes to express his gratitude to V. A. Il'in for his attention to the paper.     

Holder Continuity of the Dirichlet Solution for a General Domain

Let D be a bounded domain in Rⁿ. For a function f on the boundaryD, the Dirichlet solution of f over D is denoted by H_Df, providedthat such a solution exists. Conditions on D for H_D to transforma Hölder continuous function on D to a Hölder continuousfunction on D with the same Hölder exponent are studied.In particular, it is demonstrated here that there is no boundeddomain that preserves the Hölder continuity with exponent1. It is also also proved that a bounded regular domain D preservesthe Hölder continuity with some exponent , 0<<1,if and only if D satisfies the capacity density condition, whichis equivalent to the uniform perfectness of D if n = 2. 2000Mathematics Subject Classification 31A05, 31A20, 31B05, 31B25.     

Dimensional variance inequalities of Brascamp–Lieb type and a local approach to dimensional Prékopaʼs theorem

We give a new approach, inspired by Hörmander?s L²$L^2$-method, to weighted variance inequalities which extend results obtained by Bobkov and Ledoux. It provides in particular a local proof of the dimensional functional forms of the Brunn–Minkowski inequalities. We also present several applications of these variance inequalities, including reverse Hölder inequalities for convex functions, weighted Brascamp–Lieb inequalities and sharp weighted Poincaré inequalities for generalized Cauchy measures.