Algebraic Characterizations of Graph Regularity Conditions

It is well-known that a connected finite simple graph is regular if and only if the all-ones matrix spans an ideal of its adjacency algebra. We show that several other graph regularity conditions involving pairs and triples of vertices also have ideal theoretic characterizations in some appropriate algebras.     

Stability for Parabolic Quasiminimizers

This paper studies parabolic quasiminimizers which are solutions to parabolic variational inequalities. We show that, under a suitable regularity condition on the boundary, parabolic Q-quasiminimizers related to the parabolic p-Laplace equations with given boundary values are stable with respect to parameters Q and p. The argument is based on variational techniques, higher integrability results and regularity estimates in time. This shows that stability does not only hold for parabolic partial differential equations but it also holds for variational inequalities.     

Capacity and Potential Estimates for Quasiminimizers

We obtain estimates for quasiminimizing potentials and their level sets. A new method, based on one dimensional quasiminimizers, is used. The connection of these estimates and the maximum principle is studied.     

Partial Boundary Regularity for the Navier-Stokes Equations

We prove two conditions of local Holder continuity for suitable weak solutions to the Navier-Stokes equations near a smooth curved part of the boundary of the domain. One of these conditions has the form of the Caffarelli-Kohn-Nirenberg condition for local boundedness of suitable weak solutions at interior points of the space-time cylinder. The corresponding results near a planar part of the boundary have been established earlier by Seregin. Bibliography: 21 titles. To Nina Nikolaevna Uraltseva on the occasion of her 70th birthday __________ Published in Zapiski Nauchnykh Seminarov POMI, Vol. 310, 2004, pp. 158–190.     

Boundary Regularity for Minimal Graphs of Higher Codimensions

In this paper, the authors derive H¨older gradient estimates for graphic functions of minimal graphs of arbitrary codimensions over bounded open sets of Euclidean space under some suitable conditions.     

椭圆型方程的边界正则性与Dini条件

笔者利用Caffarelli扰动方法,证明了Poisson方程和完全非线性一致椭圆型方程在Dini条件下其粘性解的边界正则性,从而给出了文[8]定理4.11不用位势理论的简化证明.     

Efficient Removal Lemmas for Matrices

Order - It was recently proved in Alon et al. (2017) that any hereditary property of two-dimensional matrices (where the row and column order is not ignored) over a finite alphabet is testable with...     

The Boundary Regularity of Pseudo-holomorphic Disks

In this paper we will prove the continuity, the C^k-regularity after deforming suitably the domain, and the Hölder continuity, of the weakly pseudo-holomorphic disk with its boundary in a singular totally-real subvariety with only corners as its singularites.     

算子值傅里叶乘子与向量值边值问题最大正则性

向量值L^p空间上的算子值傅里叶乘子由于L．Weis在2000年的重要工作而成为泛函分析的热点之一，其对R-有界性创造性的应用使这个领域的研究耳目一新，新的结果层出不穷．本文的目的是介绍算子值傅里叶乘子的这些最新进展，以及它们在向量值边值问题最大正则性方面的应用．包括N．J．Kalton和G．Lancien给出的关于L^p-最大正则性的反例．Besov空间和Triebel空间上的算子值傅里叶乘子以及在Besov空问和Triebel空间意义下的最大正则性也是我们要介绍的内容．     

Regularity of the Solutions for Parabolic Two-Phase Free Boundary Problems

In this paper we start to develop the regularity theory of general two-phase free boundary problems for parabolic equations. In particular we consider uniformly parabolic operators in nondivergence form and we are mainly concerned with the optimal regularity of the viscosity solutions. We prove that under suitable nondegenerate conditions the solution is Lipschitz across the free boundary.     

Petrovsky系统边界控制的正则性

讨论了具有Dirichlet边界控制和同位观测的Petrovsky系统的正则性,给出了相应的直接传输算子,证明了系统在G.Weiss意义下是正则的,且其直接传输算子为零.     

Regularity of Keldys-Fichera Boundary Value Problem for Degenerate Elliptic Equations

The authors discuss the W1,p-solutions and the interior regularity of weak solutions for the Keldys-Fichera boundary value problem using the acute angle principle,the reversed Hlder inequality and the generalized poincar'e inequalities.     

Hotspot Lemmas for Noncompact Spaces

Mathematical Notes -     

Boundary Regularity for Viscosity Solutions of Fully Nonlinear Elliptic Equations

We provide regularity results at the boundary for continuous viscosity solutions to nonconvex fully nonlinear uniformly elliptic equations and inequalities in Euclidian domains. We show that (i) any solution of two sided inequalities with Pucci extremal operators is C ^{1, α} on the boundary; (ii) the solution of the Dirichlet problem for fully nonlinear uniformly elliptic equations is C ^{2, α} on the boundary; (iii) corresponding asymptotic expansions hold. This is an extension to viscosity solutions of the classical Krylov estimates for smooth solutions.     

Boundary Regularity and Nontransversal Intersection for the Fully Nonlinear Obstacle Problem

In this paper a classification is given of blowup solutions at the intersection of the free and fixed boundary corresponding to obstacle problems generated by fully nonlinear, uniformly elliptic operators. As a consequence, nontransversal intersection is shown to hold in any dimension. Several regularity results are also obtained. © 2019 Wiley Periodicals, Inc.     

Existence and Regularity for a Class of Nonlinear Hyperbolic Boundary Value Problems

The regularity of the solution of the telegraph system with nonlinear monotone boundary conditions is investigated by two methods. The first one is based on D'Alembert-type representation formulae for the solution. In the second method the telegraph system is reduced to a linear Cauchy problem with a locally Lipschitzian functional perturbation; then regularity results are established by appealing to the theory of linear semigroups.     

Regularity for Fully Nonlinear Elliptic Equations with Neumann Boundary Data

We obtain local C ^α, C ^1,α, and C ^2,α regularity results up to the boundary for viscosity solutions of fully nonlinear uniformly elliptic second order equations with Neumann boundary conditions.     

Boundary Regularity for Conformally Compact Einstein Metrics in Even Dimensions

Sufficient conditions are derived for a symmetric hyperbolic system with large variable-coefficient terms to be uniformly well posed. Examples of systems satisfying those conditions are presented.