Frequency theorem for parabolic equations and its relation to inertial manifolds theory
Abstract
We obtain a version of the Frequency Theorem (a theorem on solvability of certain operator inequalities), which allows to construct quadratic Lyapunov functionals for semilinear parabolic equations. We show that the well-known Spectral Gap Condition, which was used in the theory of inertial manifolds by C. Foias, R. Temam and G. R. Sell, is a particular case of some frequency inequality, which arises within the Frequency Theorem. In particular, this allows to construct inertial manifolds for semilinear parabolic equations (including also some non-autonomous problems) in the context of a more general geometric theory developed in our adjacent works. This theory is based on quadratic Lyapunov functionals and generalizes the frequency-domain approach used by R. A. Smith. We also discuss the optimality of frequency inequalities and its relationship with known old and recent results in the field.
Keywords
Cite
@article{arxiv.2011.12031,
title = {Frequency theorem for parabolic equations and its relation to inertial manifolds theory},
author = {Mikhail Anikushin},
journal= {arXiv preprint arXiv:2011.12031},
year = {2024}
}