Results 61 to 70 of about 2,806 (244)

Duality for Evolutionary Equations With Applications to Null Controllability

Mathematical Methods in the Applied Sciences, Volume 49, Issue 5, Page 4144-4166, 30 March 2026.
ABSTRACT We study evolutionary equations in exponentially weighted L2$$ {\mathrm{L}}^2 $$‐spaces as introduced by Picard in 2009. First, for a given evolutionary equation, we explicitly describe the ν$$ \nu $$‐adjoint system, which turns out to describe a system backwards in time. We prove well‐posedness for the ν$$ \nu $$‐adjoint system. We then apply
Andreas Buchinger, Christian Seifert
wiley   +1 more source

A MAXIMAL FUNCTION CHARACTERIZATION FOR HARDY SPACES ASSOCIATED TO NONNEGATIVE SELF-ADJOINT OPERATORS SATISFYING GAUSSIAN ESTIMATES [PDF]

, 2015
Let $L$ be a nonnegative, self-adjoint operator satisfying Gaussian estimates on $L^2(\RR^n)$. In this article we give an atomic decomposition for the Hardy spaces $ H^p_{L,max}(\R)$ in terms of the nontangential maximal functions associated with the ...
Liang Song, Lixin Yan
semanticscholar   +1 more source

Solution of certain problem with nonlocal boundary condition for one-dimensional wave equation

Вестник Самарского университета: Естественнонаучная серия
In this paper, we study a problem with nonlocal boundary condition for one-dimensional wave equation. To prove the solvability of the problem we construct biortogonal basis consisting of eigen- and adjoint-functions of not self adjoint operator.
Elvira E. Gasanova, Ludmila S. Pulkina
doaj   +1 more source

Local solvability and stability of the inverse problem for the non-self-adjoint Sturm–Liouville operator

Boundary Value Problems, 2020
We consider the non-self-adjoint Sturm–Liouville operator on a finite interval. The inverse spectral problem is studied, which consists in recovering this operator from its eigenvalues and generalized weight numbers.
Natalia P. Bondarenko
doaj   +1 more source

Mesh and Model Adaptivity for Multiscale Elastoplastic Models With Prandtl‐Reuss Type Material Laws

International Journal for Numerical Methods in Engineering, Volume 127, Issue 6, 30 March 2026.
ABSTRACT Homogenization methods simulate heterogeneous materials like composites effectively, but high computational demands can offset their benefits. This work balances accuracy and efficiency by assessing model and discretization errors of the finite element method (FEM) through an adaptive numerical scheme.
Arnold Tchomgue Simeu, Ismail Caylak, Richard Ostwald   +2 more
wiley   +1 more source

Spectral analysis of singular Hamiltonian systems with an eigenparameter in the boundary condition

Electronic Journal of Differential Equations, 2019
In this article we study a non-self-adjoint eigenparameter dependent singular differential 1D Hamiltonian system with the singular end points a and b in the Hilbert space $L_P^2((a,b);\mathbb{C}^2)$ and we consider that this 1D Hamiltonian system is ...
Bilender P. Allahverdiev
doaj  

Robust Control Design and Analysis Based on Lifting Linearization of Nonlinear Systems Under Uncertain Initial Conditions

International Journal of Robust and Nonlinear Control, Volume 36, Issue 5, Page 3047-3067, 25 March 2026.
ABSTRACT This paper presents a robust control synthesis and analysis framework for nonlinear systems with uncertain initial conditions. First, a deep learning‐based lifting approach is proposed to approximate nonlinear dynamical systems with linear parameter‐varying (LPV) state‐space models in higher‐dimensional spaces while simultaneously ...
Sourav Sinha, Mazen Farhood
wiley   +1 more source

Functions of perturbed unbounded self-adjoint operators. Operator Bernstein type inequalities [PDF]

, 2010
This is a continuation of our papers \cite{AP2} and \cite{AP3}. In those papers we obtained estimates for finite differences $(\D_Kf)(A)=f(A+K)-f(A)$ of the order 1 and $(\D_K^mf)(A)\df\sum\limits_{j=0}^m(-1)^{m-j}(m\j)f\big(A+jK\big)$ of the order $m ...
A. Aleksandrov, V. Peller
semanticscholar   +1 more source

Attribute Implication Bases From Galois Connection Structures

Mathematical Methods in the Applied Sciences, Volume 49, Issue 4, Page 2729-2753, 15 March 2026.
ABSTRACT Modeling knowledge systems by determining relationships among key variables have been and currently is a fundamental and nontrivial challenge in real‐world scenarios. Many approaches have been developed to reach this goal, but many of them are heuristic and require of alternative procedures to provide robust and tractable rules.
M. Eugenia Cornejo, Jesús Medina, Francisco José Ocaña   +2 more
wiley   +1 more source

Interpolation theorems for self-adjoint operators [PDF]

Analysis in Theory and Applications, 2009
We prove a complex and a real interpolation theorems on Besov spaces and Triebel-Lizorkin spaces associated with a selfadjoint operator $L$, without assuming the gradient estimate for its spectral kernel. The result applies to the cases where $L$ is a uniformly elliptic operator or a Schr dinger operator with electro-magnetic potential.
openaire   +4 more sources