This paper deals with some characterizations of gradient-like continuous random dynamical systems (RDS). More precisely, we establish an equivalence with the existence of random continuous section or with the existence of continuous and strict Liapunov function. However and contrary to the deterministic case, parallelizable RDS appear as a particular case of gradient-like RDS.The obtained results are generalizations of well-known analogous theorems in the framework of deterministic dynamical systems....

Consider a stochastic heat equation ∂tu=κ  ∂xx2u+σ(u)ẇ for a space–time white noise ẇ and a constant κ>0. Under some suitable conditions on the initial function u0 and σ, we show that the quantities lim sup t→∞t−1sup x∈Rln El(|ut(x)|2) and lim sup t→∞t−1ln E(sup x∈R|ut(x)|2) are equal, as well as bounded away from zero and infinity by explicit multiples of 1/κ. Our proof works by demonstrating quantitatively that the peaks of the stochastic process x↦ut(x) are highly concentrated...

This paper is devoted to the helices processes, i.e. the solutions H : ℝ × Ω → ℝd, (t, ω) ↦ H(t, ω) of the helix equation $\begin{array}{ccc}\mathit{H}\mathrm{\left(}\mathrm{0}\mathit{,\omega }\mathrm{\right)}\mathrm{=}\mathrm{0}\mathrm{;} \mathit{H}\mathrm{(}\mathit{s}\mathrm{+}\mathit{t,\omega }\mathrm{)}\mathrm{=}\mathit{H}\mathrm{\left(}\mathit{s,}\mathrm{\Phi }\mathrm{\right(}\mathit{t,\omega }\mathrm{\left)}\mathrm{\right)}\mathrm{+}\mathit{H}\mathrm{\left(}\mathit{t,\omega }\mathrm{\right)}& & \end{array}$ where Φ : ℝ × Ω → Ω, (t, ω) ↦ Φ(t, ω) is a dynamical system on a measurable space (Ω, ℱ).More precisely, we investigate dominated solutions and non differentiable solutions of the helix equation. For the last case, the Wiener helix plays a fundamental role. Moreover, some relations with the cocycle equation defined...