Invariant measure selection by noise. An example

Invariant Measure Selection by Noise an Example

We consider a deterministic system with two conserved quantities and infinity many invariant measures. However the systems possess a unique invariant measure when enough stochastic forcing and balancing dissipation are added. We then show that as the forcing and dissipation are removed a unique limit of the deterministic system is selected. The exact structure of the limiting measure depends on...

Effect of noise on the relaxation to an invariant probability measure of nonhyperbolic chaotic attractors.

We study the influence of external noise on the relaxation to an invariant probability measure for two types of nonhyperbolic chaotic attractors, a spiral (or coherent) and a noncoherent one. We find that for the coherent attractor the rate of mixing changes under the influence of noise, although the largest Lyapunov exponent remains almost unchanged. A mechanism of the noise influence on mixin...

Uniqueness of the Invariant Measure for a Stochastic PDE Driven by Degenerate Noise

We consider the stochastic Ginzburg-Landau equation in a bounded domain. We assume the stochastic forcing acts only on high spatial frequencies. The low-lying frequencies are then only connected to this forcing through the non-linear (cubic) term of the Ginzburg-Landau equation. Under these assumptions, we show that the stochastic PDE has a unique invariant measure. The techniques of proof comb...

Countable Infinitary Theories Admitting an Invariant Measure

Let L be a countable language. We characterize, in terms of definable closure, those countable theories Σ of Lω1,ω(L) for which there exists an S∞-invariant probability measure on the collection of models of Σ with underlying set N. Restricting to Lω,ω(L), this answers an open question of Gaifman from 1964, via a translation between S∞-invariant measures and Gaifman’s symmetric measure-models w...

Invariant measure for an infinite neural network