𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Instability of Spatially — Periodic States for a Family of Semilinear PDE's on an Infinite Strip

✍ Scribed by Thomas J. Bridges; Alexander Mielke


Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
895 KB
Volume
179
Category
Article
ISSN
0025-584X

No coin nor oath required. For personal study only.

✦ Synopsis


A family of time-evolution equations, for which the time-independent part is a semilinear elliptic equation on an infinite strip, is considered with attention to the instability of spatiallyperiodic states. The analysis uses a sequence of center -manifold reductions; first, every local, small norm, bounded solution is contained in a center manifold. Second, it is proved that every local, small norm, solution of the linear stability problem is also contained in a related nonautonomous center manifold. For the case where the center manifold is foliated by periodic states, with wavelength L ( s ) , parametrized by s, the level sets of a suitably defined spatial Hamiltonian functional, we prove a geometric criterion for instability: a spatially periodic state is linearly unstable in the time-dependent problem if L'(s) > 0. Properties of the manifold of periodic states and their linear stability are explicitly constructed for a family of potentials.