Results 51 to 60 of about 4,144 (169)

Null controllability of a coupled system of degenerate parabolic equations with lower order terms

Electronic Journal of Differential Equations, 2019
This article concerns the null controllability of a control system governed by coupled degenerate parabolic equations with lower order terms. For these equations, the convection terms cannot be controlled by the diffusion terms.
Jianing Xu, Qian Zhou, Yuanyuan Nie
doaj  

Preconditioning Techniques for Generalized Sylvester Matrix Equations

Numerical Linear Algebra with Applications, Volume 32, Issue 2, April 2025.
ABSTRACT Sylvester matrix equations are ubiquitous in scientific computing. However, few solution techniques exist for their generalized multiterm version, as they now arise in an increasingly large number of applications. In this work, we consider algebraic parameter‐free preconditioning techniques for the iterative solution of generalized multiterm ...
Yannis Voet
wiley   +1 more source

Strong unique continuation for the higher order fractional Laplacian

, 2019
In this article we study the strong unique continuation property for solutions of higher order (variable coefficient) fractional Schr\"odinger operators.
García-Ferrero, María-Ángeles, Rüland, Angkana   +1 more
core   +1 more source

A quantitative Carleman estimate for second-order elliptic operators [PDF]

Proceedings of the Royal Society of Edinburgh: Section A Mathematics, 2018
AbstractWe prove a Carleman estimate for elliptic second-order partial differential expressions with Lipschitz continuous coefficients. The Carleman estimate is valid for any complex-valued function u ∈ W2,2 with support in a punctured ball of arbitrary radius.
Nakić, Ivica, Rose, Christian, Tautenhahn, Martin   +2 more
openaire   +3 more sources

Stabilization for degenerate equations with drift and small singular term

Mathematical Methods in the Applied Sciences, Volume 48, Issue 4, Page 5086-5109, 15 March 2025.
We consider a degenerate/singular wave equation in lone dimension, with drift and in presence of a leading operator that is not in divergence form. We impose a homogeneous Dirichlet boundary condition where the degeneracy occurs and a boundary damping at the other endpoint.
Genni Fragnelli, Dimitri Mugnai, Amine Sbai   +2 more
wiley   +1 more source

On Carleman estimates for pseudo-differential operators [PDF]

Inventiones Mathematicae, 1972
The original purpose of this work was to prove the regularity theorems in [1] without using Fourier integral operators. Instead we use the method of Carleman estimates of H6rmander ([3], Ch. 8), with the weight function e ~Cx) replaced by a pseudo-differential operator e r ~ C x ' ~ s~x'~ of variable order s(x, 4).
openaire   +2 more sources

On the boundary of an immediate attracting basin of a hyperbolic entire function

Journal of the London Mathematical Society, Volume 111, Issue 3, March 2025.
Abstract Let f$f$ be a transcendental entire function of finite order which has an attracting periodic point z0$z_0$ of period at least 2. Suppose that the set of singularities of the inverse of f$f$ is finite and contained in the component U$U$ of the Fatou set that contains z0$z_0$. Under an additional hypothesis, we show that the intersection of ∂U$\
Walter Bergweiler, Jie Ding
wiley   +1 more source

Reachability of a second-order integro-differential equation on Riemannian manifold for a viscoelasticity model

Electronic Journal of Differential Equations, 2019
We study a reachability problem for a second-order integro-differential equation on a finite-dimensional Riemannian manifold, which is a model equation for viscoelasiticity.
Kang Zhou
doaj  

An Inverse Source Problem for Singular Parabolic Equations with Interior Degeneracy

Abstract and Applied Analysis, 2018
The main purpose of this work is to study an inverse source problem for degenerate/singular parabolic equations with degeneracy and singularity occurring in the interior of the spatial domain.
Khalid Atifi, Idriss Boutaayamou, Hamed Ould Sidi, Jawad Salhi   +3 more
doaj   +1 more source