Existence and Non-Uniqueness of Ergodic Leray-Hopf Solutions to the Stochastic Power-Law Flows
Stefanie Elisabeth Berkemeier
TL;DR
This work addresses the existence and non-uniqueness of Leray–Hopf solutions for stochastic power-law flows with shear-thinning behavior in dimensions $d\ge 3$, where the power-law index satisfies $\iota\in\left(1, \frac{2d}{d+2}\right)$. It develops a stochastic convex integration framework augmented by a novel auxiliary energy functional to enforce the energy inequality and achieve global-in-time control, yielding infinitely many probabilistically strong Leray–Hopf solutions and, via Krylov–Bogoliubov and Krein–Milman, infinitely many ergodic stationary solutions. The paper extends the non-uniqueness paradigm to stochastic non-Newtonian fluids in this intermediate index range, providing regularity, energy estimates, and ergodic properties for the constructed solutions. The results significantly advance understanding of long-time behavior, ergodicity, and energy dissipation for stochastic shear-thinning flows and open avenues for further exploration of ergodic theory in non-Newtonian SPDEs.
Abstract
We study long time behavior of shear-thinning fluid flows in $d \geq 3$ dimensions, driven by additive stochastic forcing of trace class, with power-law indices ranging from $1$ to $ \frac{2d}{d+2}$. We particularly focus on Leray-Hopf solutions, i.e. on analytically weak solutions satisfying energy inequality. Introducing a new kind of energy related functional into the technique of convex integration enables the construction of infinitely many such solutions that are probabilistically strong for a certain initial value. Furthermore, we provide global i time estimates which lead to the existence of infinitely many stationary and even ergodic Leray--Hopf solutions. These results represent the first construction of Leray-Hopf solutions in the framework of stochastic shear-thinning fluids within this range of power-law indices.
