Results 51 to 60 of about 11,357 (198)

Global and microlocal aspects of Dirac operators: Propagators and Hadamard states

Mathematische Nachrichten, Volume 298, Issue 9, Page 2942-2974, September 2025.
Abstract We propose a geometric approach to construct the Cauchy evolution operator for the Lorentzian Dirac operator on Cauchy‐compact globally hyperbolic 4‐manifolds. We realize the Cauchy evolution operator as the sum of two invariantly defined oscillatory integrals—the positive and negative Dirac propagators—global in space and in time, with ...
Matteo Capoferri, Simone Murro
wiley   +1 more source

On controllability, parametrization, and output tracking of a linearized bioreactor model

Journal of Applied Mathematics, 2003
The paper deals with a distributed parameter system related to the so-called fixed-bed bioreactor. The original nonlinear partial differential system is linearized around the steady state.
J. Tervo, M. T. Nihtilä, P. Kokkonen
doaj   +1 more source

A few remarks on time-frequency analysis of Gevrey, analytic and ultra-analytic functions

, 2012
We give a brief survey of recent results concerning almost diagonalization of pseudodifferential operators via Gabor frames. Moreover, we show new connections between symbols with Gevrey, analytic or ultra-analityc regularity and time-frequency analysis ...
Cordero, Elena, Nicola, Fabio, Rodin, Luigi   +2 more
core   +1 more source

Fundamental Solutions and Green's Functions for Certain Elliptic Differential Operators From a Pseudodifferential Algebra

Mathematical Methods in the Applied Sciences, Volume 48, Issue 13, Page 12654-12674, September 2025.
ABSTRACT We have studied possible applications of a particular pseudodifferential algebra in singular analysis for the construction of fundamental solutions and Green's functions of a certain class of elliptic partial differential operators. The pseudodifferential algebra considered in the present work, comprises degenerate partial differential ...
Heinz‐Jürgen Flad, Gohar Flad‐Harutyunyan   +1 more
wiley   +1 more source

Pseudodifferential operators with generalized symbols and regularity theory

Electronic Journal of Differential Equations, 2005
We study pseudodifferential operators with amplitudes $a_varepsilon (x,xi)$ depending on a singular parameter $varepsilon o 0$ with asymptotic properties measured by different scales.
Claudia Garetto, Todor Gramchev, Michael Oberguggenberger   +2 more
doaj  

Pseudodifferential operators and their commutators on Morrey type spaces

Demonstratio Mathematica
This paper discusses the boundedness of the commutators generated by pseudodifferential operators with Lipschitz functions, and sets up the sufficient condition such that these operators are bounded on classical Morrey spaces and generalized Morrey ...
Deng Yu-Long
doaj   +1 more source

Formal Pseudodifferential Operators in One and Several Variables, Central Extensions, and Integrable Systems

Advances in Mathematical Physics, 2015
We review some aspects of the theory of Lie algebras of (twisted and untwisted) formal pseudodifferential operators in one and several variables in a general algebraic context.
Jarnishs Beltran, Enrique G. Reyes
doaj   +1 more source

KP-KdV Hierarchy and Pseudo-Differential Operators

Communications in Advanced Mathematical Sciences, 2019
The study of KP-KdV equations are the archetype of integrable systems and are one of the most fundamental equations of soliton phenomena and a topic of active mathematical research.
Lesfari Ahmed
doaj   +1 more source

An exotic calculus of Berezin–Toeplitz operators

Mathematika, Volume 71, Issue 2, April 2025.
Abstract We develop a calculus of Berezin–Toeplitz operators quantizing exotic classes of smooth functions on compact Kähler manifolds and acting on holomorphic sections of powers of positive line bundles. These functions (classical observables) are exotic in the sense that their derivatives are allowed to grow in ways controlled by local geometry and ...
Izak Oltman
wiley   +1 more source

Decoupling for Schatten class operators in the setting of quantum harmonic analysis

Bulletin of the London Mathematical Society, Volume 57, Issue 1, Page 23-37, January 2025.
Abstract We introduce the notion of decoupling for operators, and prove an equivalence between classical ℓqLp$\ell ^qL^p$ decoupling for functions and ℓqSp$\ell ^q{\mathcal {S}}^p$ decoupling for operators on bounded sets in R2d${\mathbb {R}}^{2d}$. We also show that the equivalence depends only on the bounded set Ω$\Omega$ and not on the values of p,q$
Helge J. Samuelsen
wiley   +1 more source