Search arXivSearch

arXiv · 2111.07851

$\mathrm{L}_p$-maximal regularity for parabolic and elliptic boundary value problems with boundary conditions of mixed differentiability orders

Abstract

In the theory of non-linear parabolic and elliptic partial differential equations, the notion of maximal regularity plays an essential role in establishing existence, regularity and boundedness of solutions. There is a long history of works where sufficient conditions for maximal regularity have been established: First scalar equations and systems of finitely many coupled equations have been considered. Around 2000, the vector-valued case with infinite-dimensional range space $E$ became accessible to the development and progress in theory of $\mathcal{R}$-bounded operator families and its close connection to the $\mathcal{H}^\infty$-calculus. The ground-braking results by Denk, Hieber and Prüss for $\mathrm{L}_p$-maximal regularity of vector-valued parabolic and elliptic boundary value problems, however, were restricted to boundary conditions with homogeneous principle parts of the boundary symbol, in contrast to some previous results by Ladyszenskaya, Solonnikov and Uralceva for finite-component systems which also allow for, e.g. both Dirichlet and (mixed) flux boundary conditions at the same position. In this manuscript we aim for closing this gap, and extend the results of Denk, Hieber and Prüss to this slightly more general situation. To this end, we closely review the strategy used in their works and adapt it to the situation considered here.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Björn Augner. 2023-03-12. $\mathrm{L}_p$-maximal regularity for parabolic and elliptic boundary value problems with boundary conditions of mixed differentiability orders. https://arxiv.org/abs/2111.07851

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

A linear test approach to global controllability of third- and fifth-order nonlinear dispersive equations

We investigate third- and fifth-order nonlinear dispersive equations of KdV type on the torus and establishes approximate controllability by a fixed four-dimensional control; rather than relying solely on the saturation machinery, the analysis exploits the finite-dimensional controllability of the inviscid Burgers equation linearized around a carefully constructed return trajectory, with the trajectory itself obtained from an observable family. This ``linear test" strategy, yields more information about the structure of the control than the standard approach. In particular, the constructed control is shown to depend continuously on the initial and target states, a property that is by no means automatic in nonlinear control problems, and to decompose as a bounded linear operator applied to the data plus a fixed remainder, with the operator part interestingly independent of the order of dispersion.

math.AP

A conditional Lagrangian clock barrier at the $C^{1,\frac{1}{3}}$ threshold for axisymmetric Euler without swirl

We consider axisymmetric no-swirl solutions to the three-dimensional incompressible Euler equations, with initial velocity in $C^{1,α}\cap L^2$, where $α\in\left[\frac{1}{3},1\right)$. In a major breakthrough, Shkoller introduced a clock-and-driver framework that he used in order to prove finite-time type I blow-up below the $C^{1,\frac{1}{3}}$ threshold in this setting. Motivated by this, we define Lagrangian classes of coherent conditional solutions for which the same mechanism yields a supercritical-critical barrier to blow-up when $α\geq\frac{1}{3}$. When $α>\frac{1}{3}$, the aforementioned barrier is genuinely depleted, whereas at the critical endpoint $α=\frac{1}{3}$, we obtain an exponential bound preventing blow-up. In the general case, we formulate a matrix-clock criterion in terms of the smallest singular value of the deformation gradient and show that, under transverse cusp-tail, longitudinal, off-clock, Dini, and suitable geometric coherence hypotheses, this singular value cannot collapse in finite time. In particular, we also show that the class of such coherent solutions includes the smooth ones locally in time. In the on-axis case, the criterion reduces to the scalar clock inequality $\displaystyle \dot{J}(t)\gtrsim -B(t)J(t)-CJ(t)^{3α}$, which rules out Shkoller-type clock collapse for $α\geq\frac{1}{3}$. These results do not enlarge the known Lorentz-space global regularity classes. Rather, they in particular identify the supercritical Lagrangian obstruction dual to Shkoller's subcritical blow-up mechanism in the case $α>\frac{1}{3}$.

math.AP