Finite element approximations for the Dirichlet problem associated a second order elliptic di erential equation are studied The purpose of this paper is to discuss domain embedding preconditioners for the discrete systems The essen tial boundary condition on the interior interface is removed by introducing Lagrange multipliers The associated discrete system with a saddle point structure is prec...

in this paper, a new and ecient approach is applied for numerical approximationof the linear dierential equations with variable coecients based on operational matriceswith respect to hermite polynomials. explicit formulae which express the hermite expansioncoecients for the moments of derivatives of any dierentiable function in terms of theoriginal expansion coecients of the function itse...

This paper surveys recent results on the classi cation of di erential invari ants of transformation groups and their applications to invariant di erential equations and variational problems Consider a group of transformations acting on a jet space coordinatized by the inde pendent variables the dependent variables and their derivatives Scalar functions which are not a ected by the group transfo...

Degenerate parabolic equations of Kolmogorov type occur in many areas of analysis and applied mathematics. In their simplest form these equations were introduced by Kolmogorov in 1934 to describe the probability density of the positions and velocities of particles but the equations are also used as prototypes for evolution equations arising in the kinetic theory of gases. More recently equation...

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We consider an elliptic partial di erential operator P (x; @) with analytic coe cients and discuss the unique continuation along an analytic curve. That is, let P (x; @)u = 0 in a simply connected domain R, be an analytic curve and let fxgj2N have an accumulation point. Our main result asserts that if u(x) = 0, j 2 N , then u(x) = 0 for any x 2 . Furthermore we apply such uniqueness to an isotr...

Symbolic Reachability Computation for Families of Linear Vector Fields Gerardo Lafferriere Department of Mathematical Sciences Portland State University, P.O. Box 751, Portland, OR 97207-0751. [email protected] George J. Pappas Department of Electrical Engineering University of Pennsylvania, 200 South 33rd Street, Philadelphia, PA 19104. [email protected] Sergio Yovine VERIMAG Centre Equat...

In this study we analyze a non-overlapping domain decomposition method for the solution of elliptic Partial Di erential Equation (PDE) problems. This domain decomposition method involves the solution of Dirichlet and Neumann PDE problems on each subdomain, coupled with smoothing operations on the interfaces of the subdomains. The convergence analysis of the method at the di erential equation le...

The existence, uniqueness, and global exponential stability of traveling wave solutions of a class of nonlinear and nonlocal evolution equations are established. It is assumed that there are two stable equilibria so that a tr aveling wave is a solution that connects them. A basic assumption is the comparison principle: a smaller initial value produces a smaller solution. When applied to di eren...

We study some classes of generalized a¢ ne functions, using a generalized di¤erential. We study some properties and characterizations of these classes and we devise some characterizations of solution sets of optimization problems involving such functions or functions of related classes. Key words: colinvex, colin…ne, generalized di¤erential, optimization problem, protoconvex function, pseudocon...