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Miriam Buck

Publications and source records attributed to Miriam Buck.

3 recordsLinked to original sources

Compactly supported anomalous weak solutions for 2D Euler equations with vorticity in Hardy spaces

In a previous work (arXiv:2306.05948), we constructed by convex integration examples of energy dissipating solutions to the 2D Euler equations on $\mathbb{R}^2$ with vorticity in the real Hardy space $H^p(\mathbb{R}^2)$. In the present paper, we develop tools that significantly improve that result in two ways: Firstly, we achieve vorticities in $H^p(\mathbb{R}^2)$ in the optimal range $p\in (0,1)$ compared to $(2/3,1)$ in our previous work. Secondly, the solutions constructed here possess compact support and in particular preserve linear and angular momenta.

math.AP

On the failure of the chain rule for the divergence of Sobolev vector fields

We construct a large class of incompressible vector fields with Sobolev regularity, in dimension $d \geq 3$, for which the chain rule problem has a negative answer. In particular, for any renormalization map $\beta$ (satisfying suitable assumptions) and any (distributional) renormalization defect $T$ of the form $T = {\rm div}\, h$, where $h$ is an $L^1$ vector field, we can construct an incompressible Sobolev vector field $u \in W^{1, \tilde p}$ and a density $\rho \in L^p$ for which ${\rm div}\, (\rho u) =0$ but ${\rm div}\, (\beta(\rho) u) = T$, provided $1/p + 1/\tilde p \geq 1 + 1/(d-1)$

math.AP