activity
20242026
collaborators

5 papers

math.AP2026

Optimal energy decay rates for Klein-Gordon equations with Kelvin-Voigt damping

Filippo Dell'Oro, Lassi Paunonen, David Seifert

We study the long-time behaviour of solutions to a one-dimensional linear Klein-Gordon equation with Kelvin-Voigt damping. One of the interesting features of the equation is that t…

math.FA2026

Polynomial Stability of Non-Linearly Damped Contraction Semigroups

Lassi Paunonen, David Seifert

We investigate the stability properties of an abstract class of semi-linear systems. Our main result establishes rational rates of decay for classical solutions assuming a certain…

math.AP2025

Polynomial stability of a coupled wave-heat network

Lassi Paunonen, David Seifert

We study the long-time asymptotic behaviour of a topologically non-trivial network of wave and heat equations. By analysing the simpler wave and the heat networks separately, and t…

math.FA2025

Stability of abstract coupled systems

Serge Nicaise, Lassi Paunonen, David Seifert

We study stability of abstract differential equations coupled by means of a general algebraic condition. Our approach is based on techniques from operator theory and systems theory…

math.AP2024

Admissibility theory in abstract Sobolev scales and transfer function growth at high frequencies

Lassi Paunonen, David Seifert, Nicolas Vanspranghe

For strongly continous semigroups on Hilbert spaces, we investigate admissibility properties of control and observation operators shifted along continuous scales of spaces built by…