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Prox-regularization and solution of ill-posed elliptic variational inequalities

Alexander Kaplan, Rainer Tichatschke (1997)

Applications of Mathematics

In this paper new methods for solving elliptic variational inequalities with weakly coercive operators are considered. The use of the iterative prox-regularization coupled with a successive discretization of the variational inequality by means of a finite element method ensures well-posedness of the auxiliary problems and strong convergence of their approximate solutions to a solution of the original problem. In particular, regularization on the kernel of the differential operator and regularization...

Pseudodifferential Operators and Weighted Normed Symbol Spaces

Sjöstrand, J. (2008)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 35S05.This work is the continuation of two earlier ones by the author and stimulated by many more recent contributions. We develop a very general calculus of pseudodifferential operators with microlocally defined normed symbol spaces. The goal was to attain the natural degree of generality in the case when the underlying metric on the cotangent space is constant. We also give sufficient conditions for our operators to belong to Schatten–von Neumann classes....

Pseudo-Differential Operators in a Wave Diffraction Problem with Impedance Conditions

Castro, L.P., Kapanadze, D. (2008)

Fractional Calculus and Applied Analysis

Mathematics Subject Classification: 35J05, 35J25, 35C15, 47H50, 47G30We consider an impedance boundary-value problem for the Helmholtz equation which models a wave diffraction problem with imperfect conductivity on a strip. Pseudo-differential operators are used to deal with this wave diffraction problem. Therefore, single and double layer potentials allow a reformulation of the problem into a system of integral equations. By using operator theoretical methods, the well-posedness of the problem...

Pseudodifferential operators on non-quasianalytic classes of Beurling type

C. Fernández, A. Galbis, D. Jornet (2005)

Studia Mathematica

We introduce pseudodifferential operators (of infinite order) in the framework of non-quasianalytic classes of Beurling type. We prove that such an operator with (distributional) kernel in a given Beurling class ( ω ) ' is pseudo-local and can be locally decomposed, modulo a smoothing operator, as the composition of a pseudodifferential operator of finite order and an ultradifferential operator with constant coefficients in the sense of Komatsu, both operators with kernel in the same class ( ω ) ' . We also...

Pseudomonotonicity and nonlinear hyperbolic equations

Dimitrios A. Kandilakis (1997)

Commentationes Mathematicae Universitatis Carolinae

In this paper we consider a nonlinear hyperbolic boundary value problem. We show that this problem admits weak solutions by using a lifting result for pseudomonotone operators and a surjectivity result concerning coercive and monotone operators.

Pseudo-spectrum for a class of semi-classical operators

Karel Pravda-Starov (2008)

Bulletin de la Société Mathématique de France

We study in this paper a notion of pseudo-spectrum in the semi-classical setting called injectivity pseudo-spectrum. The injectivity pseudo-spectrum is a subset of points in the complex plane where there exist some quasi-modes with a precise rate of decay. For that reason, these values can be considered as some ‘almost eigenvalues’ in the semi-classical limit. We are interested here in studying the absence of injectivity pseudo-spectrum, which is characterized by a global a priori estimate. We prove...

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