Ghost-patterning and non-patterning in a draining film model

Patterns can form when the uniform state of any system is unstable so that some non-uniform motif grows in amplitude. Here, we identify an alternative way to form non-trivial structures, which we call “ghost-patterns”. Ghost-patterns emerge from noisy initial conditions when all non-uniform modes decay in amplitude except for one non-trivial motif which fails to decay. Hence, in seeking structured states, it is not necessary to find positive growth rates. We demonstrate ghost-patterns in an idealized non-equilibrium model intended to emulate draining thin-film suspensions. Graphical abstract