Results 21 to 30 of about 300 (51)

A characterization of the generators of analytic C0‐semigroups in the class of scalar type spectral operators

open access: yesAbstract and Applied Analysis, Volume 2004, Issue 12, Page 1007-1018, 2004., 2004
In the class of scalar type spectral operators in a complex Banach space, a characterization of the generators of analytic C0‐semigroups in terms of the analytic vectors of the operators is found.
Marat V. Markin
wiley   +1 more source

Lyapunov theorems for Banach spaces

open access: yes, 1993
We present a spectral mapping theorem for semigroups on any Banach space $E$. From this, we obtain a characterization of exponential dichotomy for nonautonomous differential equations for $E$-valued functions.
Latushkin, Yuri   +1 more
core   +4 more sources

Analyticity and Riesz basis property of semigroups associated to damped vibrations [PDF]

open access: yes, 2007
Second order equations of the form $z'' + A_0 z + D z'=0$ in an abstract Hilbert space are considered. Such equations are often used as a model for transverse motions of thin beams in the presence of damping.
Jacob, Birgit   +2 more
core   +3 more sources

An inverse problem for a second‐order differential equation in a Banach space

open access: yesAbstract and Applied Analysis, Volume 2004, Issue 12, Page 997-1005, 2004., 2004
We consider the problem of determining the unknown term in the right‐hand side of a second‐order differential equation with unbounded operator generating a cosine operator function from the overspecified boundary data. We obtain necessary and sufficient conditions of the unique solvability of this problem in terms of location of the spectrum of the ...
Y. Eidelman
wiley   +1 more source

A Massera‐type criterion for almost periodic solutions of higher‐order delay or advance abstract functional differential equations

open access: yesAbstract and Applied Analysis, Volume 2004, Issue 10, Page 881-896, 2004., 2004
Let u be a given bounded uniformly continuous mild solution of a higher‐order abstract functional differential equation of delay or advance type. We give a so‐called Massera‐type criterion for the existence of a mild solution, which is a “spectral component” of u with spectrum similar to the one of the forcing term f.
Nguyen Van Minh, Ha Binh Minh
wiley   +1 more source

Asymptotic parabolicity for strongly damped wave equations

open access: yes, 2013
For $S$ a positive selfadjoint operator on a Hilbert space, \[ \frac{d^2u}{dt}(t) + 2 F(S)\frac{du}{dt}(t) + S^2u(t)=0 \] describes a class of wave equations with strong friction or damping if $F$ is a positive Borel function.
Fragnelli, Genni   +3 more
core   +1 more source

On the Lw2‐boundedness of solutions for products of quasi‐integro differential equations

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 10, Page 639-659, 2003., 2003
Given a general quasi‐differential expressions τ1, τ2, …, τn each of order n with complex coefficients and their formal adjoints are τ1+,τ2+,…,τn+ on [0, b), respectively, we show under suitable conditions on the function F that all solutions of the product of quasi‐integrodifferential equation [∏j=1nτj]y=wF(t,y,∫0tg(t,s,y,y′,…,y(n2−1)(s))ds) on [0, b),
Sobhy El-Sayed Ibrahim
wiley   +1 more source

Almost periodic solutions of periodic linear partial functional differential equations

open access: yes, 2018
We study conditions for the abstract periodic linear functional differential equation $\dot{x}=Ax+F(t)x_t+f(t)$ to have almost periodic with the same structure of frequencies as $f$.
Luong, Vu Trong, Van Minh, Nguyen
core   +1 more source

Linear neutral partial differential equations: a semigroup approach

open access: yesInternational Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 23, Page 1433-1445, 2003., 2003
We study linear neutral PDEs of the form (∂/∂t)Fut = BFut + Φut, t ≥ 0; u0(t) = φ(t), t ≤ 0, where the function u(⋅) takes values in a Banach space X. Under appropriate conditions on the difference operator F and the delay operator Φ, we construct a C0‐semigroup on C0(ℝ−, X) yielding the solutions of the equation.
Rainer Nagel, Nguyen Thieu Huy
wiley   +1 more source

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