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1.
Let {T
p:q
1 p q
2} be a family of consistent C
0 semigroups on L
p(), with q
1,q
2 [1,) and open. We show that certain commutator conditions on T
p and on the resolvent of its generator A
p ensure the p independence of the spectrum of A
p for p [q
1,q
2.Applications include the case of Petrovskij correct systems with Hölder continuous coefficients, Schrödinger operators, and certain elliptic operators in divergence form with real, but not necessarily symmetric, or complex coefficients. 相似文献
2.
In this paper we study the regularity theory of the solutions of a class of degenerate elliptic equations in divergence form. By introducing a proper distance and applying the compactness method we establish the Hölder type estimates for the weak solutions. 相似文献
3.
4.
Pierre Dreyfuss 《Potential Analysis》2007,26(2):101-119
We prove that under some global conditions on the maximum and the minimum eigenvalue of the matrix of the coefficients, the gradient of the (weak) solution of some degenerate elliptic equations has higher integrability than expected. Technically we adapt the Giaquinta–Modica regularity method in some degenerate cases. When the dimension is two, a consequence of our result is a new Hölder continuity result for the weak solution. 相似文献
5.
On Mixed Error Estimates for Elliptic Obstacle Problems 总被引:1,自引:0,他引:1
We establish in this paper sharp error estimates of residual type for finite element approximation to elliptic obstacle problems. The estimates are of mixed nature, which are neither of a pure a priori form nor of a pure a posteriori form but instead they are combined by an a priori part and an a posteriori part. The key ingredient in our derivation for the mixed error estimates is the use of a new interpolator which enables us to eliminate inactive data from the error estimators. One application of our mixed error estimates is to construct a posteriori error indicators reliable and efficient up to higher order terms, and these indicators are useful in mesh-refinements and adaptive grid generations. In particular, by approximating the a priori part with some a posteriori quantities we can successfully track the free boundary for elliptic obstacle problems. 相似文献
7.
Lung-an Ying 《偏微分方程(英文版)》2003,16(1):37-48
We study the structure of solutions to the interface problems for second order quasi-linear elliptic partial differential equations in two dimensional space. We prove that each weak solution can be decomposed into two parts near singular points, a finite sum of functions in the form of cr^α log^m rφ(θ) and a regular one w. The coefficients c and the C^{1,α} norm of w depend on the H¹-norm and the C^{º,α}-norm of the solution, and the equation only. 相似文献
8.
We consider a Dirichlettype problem for a system of elliptic equations of second order with a strong degeneracy at an inner point of the domain, when, in a neighborhood of this point, the principal term of the asymptotics of a solution is additionally given. We prove the existence and uniqueness of a solution of the problem considered in a weighted class of Hölder vector functions. 相似文献
9.
E. R. Jakobsen 《BIT Numerical Mathematics》2004,44(2):269-285
In this paper we provide estimates of the rates of convergence of monotone approximation schemes for non-convex equations in one space-dimension. The equations under consideration are the degenerate elliptic Isaacs equations with x-depending coefficients, and the results applies in particular to certain finite difference methods and control schemes based on the dynamic programming principle. Recently, Krylov, Barles, and Jakobsen obtained similar estimates for convex Hamilton–Jacobi–Bellman equations in arbitrary space-dimensions. Our results are only valid in one space-dimension, but they are the first results of this type for non-convex second-order equations. 相似文献
10.
Summary We prove existence and optimal decay properties of a Green's matrix for elliptic systems of second order. The results follow
from regularity theorems in weak Lebesgue spaces which can be obtained from the classicalL
p
theory using interpolation theorems.
This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag. 相似文献
11.
We give examples of discontinuous solutions and of unbounded solutions of linear isotropic degenerate elliptic equations. Discontinuous solutions exist even when both the maximum eigenvalue and the inverse of the minimum eigenvalue of the matrix of the coefficients are in the intersection of all the Lp spaces. 相似文献
12.
We consider nonlinear elliptic problems whose prototype is
, with Ω bounded open subset of and p > 1. When several notions of solutions have been introduced; we refer to distributional solutions which can be obtained by an approximation
procedure and point out that the question can be faced by a new method which uses symmetrization techniques. In this way we
prove both a priori estimates and a continuity with respect to data result which allow us to deduce existence and uniqueness
of the solution.
相似文献
13.
14.
Abstract We study nonlinear noncoercive elliptic problems with measure data, proving first that the global estimates already known when the problem is coercive are still true for noncoercive problems. We then prove new estimates, on sets far from the support of the singular part of the right-hand side, in the energy space associated to the operator, which entails additional regularity results on the solutions. 相似文献
15.
O. Mali 《Numerical Functional Analysis & Optimization》2017,38(1):58-79
In this article, functional type a posteriori error estimates are presented for a certain class of optimal control problems with elliptic partial differential equation constraints. It is assumed that in the cost functional the state is measured in terms of the energy norm generated by the state equation. The functional a posteriori error estimates developed by Repin in the late 1990s are applied to estimate the cost function value from both sides without requiring the exact solution of the state equation. Moreover, a lower bound for the minimal cost functional value is derived. A meaningful error quantity coinciding with the gap between the cost functional values of an arbitrary admissible control and the optimal control is introduced. This error quantity can be estimated from both sides using the estimates for the cost functional value. The theoretical results are confirmed by numerical tests. 相似文献
16.
利用Moser-Nash迭代和稠密引理,得到了在自然增长下的非线性退化椭圆方程有界弱解具有某一Hlder指数的正则性;在已知数据的进一步正则性下,建立了具有任意γ满足0≤γ<κ的优化Hlder连续性指数,其中κ是A-调和函数的局部Hlder连续指数. 相似文献
17.
MUCHUNLAI TANGXIANJIANG 《高校应用数学学报(英文版)》1998,13(1):31-38
In this paper L^p-L^q estimates for the solution u(x,t) to the following perturbed high-er order hyperbolic equation are considered, (ρπ--a△)(ρπ--b△)u V(x)u=O, x∈R^n,n≥6, ρ1eu(x,O) = O, ρ^3eu(x,O) = f(x), (j = O,1,2).We assume that the otential V(x) and the initial data f(x) are compactly supported, andV(x) is sufficiently small, then the solution u (x,t) of the above problem satisfies the same L^p-L^q estimates as that of the unperturbed problem. 相似文献
18.
19.
In this paper,the higher order asymptotic behaviors of boundary blow-up solutions to the equation■in bounded smooth domain■are systematically investigated for p and q.The second and third order boundary behaviours of the equation are derived.The results show the role of the mean curvature of the boundary■and its gradient in the high order asymptotic expansions of the solutions. 相似文献
20.
HE Yue School of Mathematics Computing Science Zhongshan University Guangzhou China School of Mathematics Computing Science Nanjing Normal University Nanjing China. 《数学年刊A辑(中文版)》2007,(5)
研究一类特殊退化椭圆型方程边值问题的适定性,该类问题与双曲空间中的极小图的Dirichlet问题,曲面的无穷小等距形变刚性问题等等的研究密切相关,而这类方程的特征形式在区域上是变号的,其适定性是值得深入讨论的.最后,得到这类边值问题的H~1弱解的存在性和唯一性. 相似文献